Pavel Zlotarenchuk's questions

我有一个列表（ListView），每个单元格都有一个 . 如果单击屏幕底部的 TextInput，则列表会滚动，以使元素位于键盘上方并且键盘打开，然后立即关闭（问题一），但是如果将光标放在列表的最后一个元素，然后在关闭键盘后，列表也会向后滚动，事实证明根本无法向其中输入数据。请帮忙，提前谢谢

编码：

renderCell(rowData, rowID) {
        return (
            <View style={styles.measurement}>
                <Image style={styles.image}
                       source={{uri: rowData.picture}}/>
                <View style={{margin: 10}}>
                    <Text style={styles.text}>{this.getName(rowData)}</Text>
                    <TextInput style={{marginTop: 4, height: 40, borderWidth: 1, fontSize: 14, alignSelf: 'flex-start'}}
                               keyboardType='numeric'
                               maxLength={6}
                               numberOfLines={1}
                               placeholder="value in centimeters"
                               value={this.getValue(this.state.sizes, rowID)}
                               onChangeText={(text) => {
                                   this.state.values[rowID] = {
                                       name_ru: rowData.name_ru,
                                       name_en: rowData.name_en,
                                       value: text
                                   }
                               }}/>
                </View>
            </View>
        )
    }

PS我尝试使用react-native-keyboard-aware-scroll-view - 没有结果

不久前，我开始学习 React Native。并且遇到了问题。我正在尝试解析https://www.cryptocompare.com/api/data/coinlist 并从数据部分获取图片链接我得到了部分本身

dataImages: Array(responseJson.Data)
console.log(this.state.dataImages[0])

看起来像这样：

"42": {
"Id": "4321",
"Url": "/coins/42/overview",
"ImageUrl": "/media/12318415/42.png",
"Name": "42",
"Symbol": "42",
"CoinName": "42 Coin",
"FullName": "42 Coin (42)",
"Algorithm": "Scrypt",
"ProofType": "PoW/PoS",
"FullyPremined": "0",
"TotalCoinSupply": "42",
"PreMinedValue": "N/A",
"TotalCoinsFreeFloat": "N/A",
"SortOrder": "34",
"Sponsored": false
},
"300": {
"Id": "749869",
"Url": "/coins/300/overview",
"ImageUrl": "/media/27010595/300.png",
"Name": "300",
"Symbol": "300",
"CoinName": "300 token",
"FullName": "300 token (300)",
"Algorithm": "N/A",
"ProofType": "N/A",
"FullyPremined": "0",
"TotalCoinSupply": "300",
"PreMinedValue": "N/A",
"TotalCoinsFreeFloat": "N/A",
"SortOrder": "2212",
"Sponsored": false
},...

尽管我添加了“[0]”，但如果在输入“.DOGE”（元素名称）之后，我可以获得元素但我需要从所有元素中获取 ImageUrl 或 Name 字段请告诉我我做错了什么.

再会。有一个代码：

ExecutorService executorService = Executors.newFixedThreadPool(3);
        for (int i = 0; i < 3; i++) {
            executorService.execute(new ParallelRunnable(parallelGraph, parallelLineData, i));
    }

它创建一个线程池。问题是：如何捕获这个执行器的所有线程的完成并在完成时执行代码。动作发生在 android 上。

有一个代码：

public class BackupHelper extends BackupAgentHelper {

    public static final Object[] DATA_LOCK = new Object[0];

    @Override
    public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data,
                         ParcelFileDescriptor newState) throws IOException {

        synchronized (DATA_LOCK) {
            super.onBackup(oldState, data, newState);
        }
        Log.d("BackupHelper", "onBackup()");
    }

    @Override
    public void onCreate(){
        FileBackupHelper db = new FileBackupHelper(this, DatabaseHelper.DATABASE_NAME);
        addHelper(DatabaseHelper.DATABASE_NAME, db);
        Log.d("BackupHelper", "onCreate()");
    }

    @Override
    public File getFilesDir(){
        File path = getDatabasePath(DatabaseHelper.DATABASE_NAME);
        return path.getParentFile();
    }

    @Override
    public void onRestore(BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState)
            throws IOException {
        Log.d("BackupHelper", "onRestore()");
        synchronized (DATA_LOCK) {
            super.onRestore(data, appVersionCode, newState);
        }
    }
}

清单说：

android:allowBackup="true"
android:fullBackupOnly="true"
android:backupInForeground="true"
android:backupAgent=".app.db.BackupHelper"

我这样称呼：

private BackupManager backupManager;
backupManager = new BackupManager(context);

但即使是来自 BackupHelper 的日志也不会显示。也许我做错了什么？请帮助，我已经挣扎了几天。

我正在编写一个应用程序，在工作时，它将数据保存在 SQLite 中。重要的是应用程序在删除之前将数据保存在云中，然后在安装后将其拉起。您无需注册即可实施。

是否可以使用谷歌（使用谷歌帐户）本地执行此操作？如果可能，怎么做？还有其他方法吗？

同志们下午好，我使用 MPAndroidChart 库绘制了价格随时间变化的线性图。Y 标尺没有问题，但我无法让 X 标尺充分发挥作用。有水将所需值代入此刻度，具体取决于位置：

IAxisValueFormatter formatter = new IAxisValueFormatter() {
    @Override
    public String getFormattedValue(float value, AxisBase axis) {
        return quarters[(int) value];
    }
;
XAxis xAxis = mLineChart.getXAxis();
xAxis.setGranularity(1f); // minimum axis-step (interval) is 1
xAxis.setValueFormatter(formatter);

但是有一个问题，加载器在加载结束时重新绘制图形，加载器通过选择用户想要查看结果的时间段来启动。如果我们想在 10 分钟内看到结果，那么来自服务器的值少于 10 个，如果在一天内，则超过 100 个。问题是由于某种原因该值没有更新，而当100个值后我需要回看10个，它在轴列表中查找100个中的Y值，自然找不到它们，因为我们只有10个要崩溃。实际上问题是如何重置这些值？在将数据传递给图表之前，我执行 mChart.clear(); 我不明白出了什么问题。请帮助理解。

同志们好。有一个fragment dialog（一个单独的类）是通过接口创建的，通过点击listView中的一个item（点击在adapter中处理，在activity中调用接口）。数据被传递到这个对话框（用于编辑和保存到数据库）。旋转手机时如何保存对话框的状态？更准确地说，我像这样保存对话框本身的状态：

@Override
    public void onSaveInstanceState(Bundle savedInstanceState) {
        super.onSaveInstanceState(savedInstanceState);
        if (builder != null) {
            savedInstanceState.putBoolean("showDialog", true);
            savedInstanceState.putString("id", String.valueOf(id));
            savedInstanceState.putString("key", key);
            if (!String.valueOf(posTextView.getText()).equals("")) {
                savedInstanceState.putDouble("posTextView", Double.parseDouble(String.valueOf(posTextView.getText())));
            } else {
                savedInstanceState.putDouble("posTextView", 0);
            }
            if (!String.valueOf(priceTextView.getText()).equals("")) {
                savedInstanceState.putDouble("priceTextView", Double.parseDouble(String.valueOf(priceTextView.getText())));
            } else {
                savedInstanceState.putDouble("priceTextView", 0);
            }
            savedInstanceState.putLong("dateLong", resultDate);
        } else {
            savedInstanceState.putBoolean("showDialog", false);
        }
    }

我恢复

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    setRetainInstance(true);
    if (savedInstanceState != null && savedInstanceState.getBoolean("showDialog")) {
        this.id= savedInstanceState.getInt("id");
        this.key= savedInstanceState.getString("key");
        this.quantity = savedInstanceState.getDouble("posTextView");
        this.price = savedInstanceState.getDouble("priceTextView");
        this.dateLong = savedInstanceState.getLong("dateLong");
    }

旋转后如何在活动中调用包含此数据的对话框？除非旧的已关闭，否则不会创建新的。对话框构造函数（即使在恢复数据后也需要上下文，否则为 nullPointerException）

 public EditPortfolioDialogFragment newInstance(Integer id, String key, double quantity, double price, long dateLong,
                                                   boolean buy, Context context, PortfolioItemSaveListener portfolioItemSaveListener) {
        EditPortfolioDialogFragment dialogFragment = new EditPortfolioDialogFragment();

        this.coinId = id;
        if (key != null) {
            this.key = key;
            this.oldKey = key;
        } else {
            this.key = "abc";
        }
        this.quantity = quantity;
        this.price = price;
        this.dateLong = dateLong;

        this.context = context;
        this.portfolioItemSaveListener = portfolioItemSaveListener;
        return dialogFragment;
    }

一个小时我不明白为什么工作室强调 return new ProfessionListLoader(MainActivity.this); 并且不允许应用程序运行。

import android.os.Bundle;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.Loader;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import com.tanat.english_for_professions.R;
import com.tanat.english_for_professions.loader.ProfessionListLoader;
import java.util.ArrayList;
import butterknife.BindView;
import butterknife.ButterKnife;

public class MainActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<ArrayList<String>> {
    private int LOADER_ID = 0;

    @BindView(R.id.professionList)
    ListView professionList;
    @BindView(R.id.toolbar)
    Toolbar toolbar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_activity);
        ButterKnife.bind(this);
        setSupportActionBar(toolbar);
        loadData();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();

        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    public Loader<ArrayList<String>> onCreateLoader(int id, Bundle args) {
        return new ProfessionListLoader(MainActivity.this);
    }

    @Override
    public void onLoadFinished(Loader<ArrayList<String>> loader, ArrayList<String> data) {

    }

    @Override
    public void onLoaderReset(Loader<ArrayList<String>> loader) {

    }

    private void loadData() {
        ArrayList data = null;
        if (data == null || data.size() == 0) {
            getSupportLoaderManager().initLoader(LOADER_ID, null, this);
        } else {
            createListAdapter(data);
        }
    }

    public void createListAdapter(ArrayList data) {
        ArrayAdapter<String> adapter;
        if (data != null) {
            adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, data);
            professionList.setAdapter(adapter);
        }
    }
}

装载机：

import android.content.AsyncTaskLoader;
import android.content.Context;
import android.util.Log;
import com.tanat.english_for_professions.R;
import com.tanat.english_for_professions.utils.JsonDisperse;
import org.json.JSONException;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;

public class ProfessionListLoader extends AsyncTaskLoader<ArrayList<String>> {
    private Context context;

    public ProfessionListLoader(Context context) {
        super(context);
        this.context = context;
    }

    String jsonString = "";
    InputStream inputStream;
    HttpURLConnection urlConnection = null;
    BufferedReader reader = null;

    @Override
    public ArrayList<String> loadInBackground() {
        try {
            URL url = new URL("url-url-url");

            urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestMethod("GET");
            urlConnection.connect();

            inputStream = url.openConnection().getInputStream();
            StringBuffer buffer = new StringBuffer();
            reader = new BufferedReader(new InputStreamReader(inputStream));

            String line;
            while ((line = reader.readLine()) != null) {
                buffer.append(line);
            }
            jsonString = buffer.toString();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
        Log.d("loader", jsonString);
        JsonDisperse jsonDisperse = new JsonDisperse();
        jsonDisperse.saveStaticString(jsonString);

        try {
            return jsonDisperse.getListProfession(Integer.parseInt(context.getString(R.string.language)));
        } catch (JSONException e) {
            e.printStackTrace();
            return null;
        }
    }
}

如果你悬停，上下文会原谅，但我也给它。 请帮帮我。

实际上在 Realm 中，模型类的名称与表的名称相同。以及如何创建许多具有不同名称但每个模型有 1 个模型的表？也就是说，假设有一个鞋品牌列表，这是1个表，每个品牌都有一个集合（这些表和品牌一样多，虽然可能还有更多，但我们不会分心）每个鞋子集合中的模型有：id、颜色、价格......（不取决于鞋子的集合或品牌）假设您需要解析 JSON 并将其保存到表中。

一、品牌列表

2.collection_dolce

3.collection_eccet

...................................

N.collection_xxx

如何为一个模型创建具有不同名称的这些表？在品牌列表中，您可以添加一个包含集合表名称的列

ButterKnife 库已经连接到项目并且可以工作，但是如何将它连接到这个片段。

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    inflater.inflate(R.layout.profession_list_fragment, null);

    ButterKnife.bind(this, ???);

    serviceIntent = new Intent(getActivity(), ServiceLoad.class);
    setConnection();

    loadData ();

    return super.onCreateView(inflater, container, savedInstanceState);
}

提前致谢。

先生们好！有这样的代码

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:elevation="10dp"
    android:background="@drawable/card_background"
    >

    <TextView
        android:id="@+id/textView_dialog_address"
        style="@style/SecondaryTextView"
        android:layout_width="140dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="12dp"
        android:layout_marginRight="12dp"
        android:layout_marginTop="12dp"
        android:text="text"
        android:textAlignment="center"
        android:textStyle="bold"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

它看起来像这样：

我需要 infoWindow 在这样的标记下：

+我只是无法在我一直在争取第三天的信息窗口下充分添加阴影，请尽你所能帮助任何人）

有以下片段：package tanat.androidtesttask.fragments；

import android.content.BroadcastReceiver;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.database.sqlite.SQLiteDatabase;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.RequiresApi;
import android.support.v4.widget.SwipeRefreshLayout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;

import com.google.firebase.crash.FirebaseCrash;

import java.util.ArrayList;

import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.OnClick;

import io.realm.Realm;
import io.realm.RealmAsyncTask;
import io.realm.RealmConfiguration;
import io.realm.RealmResults;
import tanat.androidtesttask.BuildConfig;
import tanat.androidtesttask.activity.InfoRoutActivity;
import tanat.androidtesttask.R;
import tanat.androidtesttask.activity.MainActivity;
import tanat.androidtesttask.database.DBHelper;
import tanat.androidtesttask.database.RealmController;
import tanat.androidtesttask.model.RealmModel;
import tanat.androidtesttask.service.BroadcastService;
import tanat.androidtesttask.utils.JSONParsing;
import tanat.androidtesttask.utils.LoadLocalData;
import tanat.androidtesttask.errorreporter.Log;

public class ListFragment extends android.app.ListFragment implements SwipeRefreshLayout.OnRefreshListener{

    @BindView(R.id.refresh) SwipeRefreshLayout swipeRefreshLayout;
    @BindView(R.id.standart_layout) LinearLayout contentLayout;
    @BindView(R.id.error_layout) LinearLayout errorLayout;
    @BindView(R.id.errorTextView) TextView errorTextView;

    //button to update if an error
    @OnClick(R.id.refreshButton)
    void onRefreshClick() {
        onRefresh();
    }

    private View rootView;

    private final static int STATUS_START = 100;
    private final static int STATUS_FINISH = 200;
    private final static String PARAM_RESULT = "result";
    private final static String PARAM_STATUS = "status";
    public final static String BROADCAST_ACTION = "tanat.androidtesttask.activity";
    private BroadcastReceiver broadcastReceiver;

    private LoadLocalData loadLocalData;
    DBHelper dbHelper;
    Realm realm;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        rootView = inflater.inflate(R.layout.fragment_item, null);
        ButterKnife.bind(this, rootView);

        swipeRefreshLayout.setOnRefreshListener(this);

        intent = new Intent(getActivity(), BroadcastService.class);
        setsConnection();

        loadLocalData = new LoadLocalData(getActivity());

        dbHelper = new DBHelper(getActivity());

        Realm.init(getActivity());

        setRetainInstance(true);
        return rootView;
    }

    Intent intent;
    private ArrayList data = null;

    private void setsConnection (){
        broadcastReceiver = new BroadcastReceiver() {
            public void onReceive(Context context, Intent intent) {
                int status = intent.getIntExtra(PARAM_STATUS, 0);
                if (status == STATUS_START) {
                    if (BuildConfig.USE_LOG) {Log.d("server start task");}
                    FirebaseCrash.log("server start task");
                }
                if (status == STATUS_FINISH) {
                    if (BuildConfig.USE_LOG) {Log.d("server finish task");}
                    FirebaseCrash.log("server finish task");

                    data = intent.getStringArrayListExtra(PARAM_RESULT);
                    procesShowData();

                    saveCache();
                }
            }
        };
        IntentFilter intFilt = new IntentFilter(BROADCAST_ACTION);

        getActivity().registerReceiver(broadcastReceiver, intFilt);
    }

    @Override
    public void onStart() {
        super.onStart();
        loadData();
        procesShowData();
    }

    @Override
    public void onPause(){
        // save the data so that you do not load it again when return to the fragment
        if(data != null && !data.get(0).toString().equals("false")) {
            if (BuildConfig.USE_LOG) {Log.d("pause before save");}
            //save data in file
            loadLocalData.writeFile(FILE_NAME, new JSONParsing().dispatch());
        }
        if (BuildConfig.USE_LOG) {Log.d("pause last save");}
        super.onPause();
    }

    @Override
    public void onDestroy() {
        getActivity().unregisterReceiver(broadcastReceiver);
        getActivity().stopService(intent);
        super.onDestroy();
    }

    @RequiresApi(api = Build.VERSION_CODES.M)
    @Override
    public void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);
        loadLocalData.writeFile(FILE_NAME, new JSONParsing().dispatch());

        Intent intent = new Intent(ListFragment.this.getContext(), InfoRoutActivity.class);
        intent.putExtra("position", position);
        startActivity(intent);
    }

    @Override
    public void onRefresh() {
        swipeRefreshLayout.setRefreshing(true);

        getActivity().startService(intent);
    }

    private String FILE_NAME = "JsonTestTask";
    // loading data
    private void loadData (){
        // start show progress dialog
        swipeRefreshLayout.setRefreshing(true);

        // upload local data
        data = loadLocalData.returnArray(FILE_NAME);

        //if there is no data, load it from the network
        if (data == null || data.size() == 0 || data.get(0).toString().equals("false")) {
            data = null;
            getActivity().startService(intent);
        }
    }

    private void procesShowData (){
        if(data != null){
            if(data.get(0).toString().equals("false")){
                contentLayout.setVisibility(View.INVISIBLE);
                errorLayout.setVisibility(View.VISIBLE);
                errorTextView.setText(data.get(1).toString());
            } else {
                // if network operation true
                errorLayout.setVisibility(View.INVISIBLE);
                contentLayout.setVisibility(View.VISIBLE);
                // create list
                createdList();
            }
        } else {
            errorLayout.setVisibility(View.INVISIBLE);
            contentLayout.setVisibility(View.VISIBLE);
            createdList();
        }
        if (data != null) {
            swipeRefreshLayout.setRefreshing(false);
        }
    }

    private ArrayAdapter<String> adapter;

    // create list
    public void createdList(){
        if (data != null){
            adapter = new ArrayAdapter<String>(getActivity(),
                    android.R.layout.simple_list_item_1, data);
        } else {
            adapter = null;
        }
        setListAdapter(adapter);
    }

    public void saveCache (){
        int checkTypeDatabase = new MainActivity().checkTypeDatabase;
        if (checkTypeDatabase == 1) {
            // use Realm database
            CacheRealm cacheRealm = new CacheRealm();
            cacheRealm.execute();

        } else if (checkTypeDatabase == 2) {
            // use SQLite database
            CacheSQLite cacheSQLite = new CacheSQLite();
            cacheSQLite.execute();
        }
    }

    private int id = 0;

    private int name_from_city = 1;
    private int highlight_from_city = 2;
    private int id_from_city = 3;

    private int name_to_city = 4;
    private int highlight_to_city = 5;
    private int id_to_city = 6;

    private int info = 7;

    private int from_date = 8;
    private int from_time = 9;
    private int from_info = 10;

    private int to_date = 11;
    private int to_time = 12;
    private int to_info = 13;

    private int price = 14;
    private int bus_id = 15;
    private int reservation_count = 16;

    // Caching the query in the Realm database
    class CacheRealm extends AsyncTask<Void, Void, Void> {

        @Override
        protected Void doInBackground(Void... params) {
            ArrayList<String[]> arrayList = new JSONParsing().examineJSONObj();

            Realm realm = Realm.getDefaultInstance();

            try {
            realm.beginTransaction();

            RealmResults<RealmModel> results = realm.where(RealmModel.class).findAll();
            results.deleteAllFromRealm();

            for (int i = 0; i < arrayList.size(); i++) {
                RealmModel realmObject = realm.createObject(RealmModel.class);

                realmObject.setId(Integer.valueOf(arrayList.get(i)[id]));

                realmObject.setName_from_city(arrayList.get(i)[name_from_city]);
                realmObject.setHighlight_from_city(arrayList.get(i)[highlight_from_city]);
                realmObject.setId_from_city(Integer.valueOf(arrayList.get(i)[id_from_city]));

                realmObject.setName_to_city(arrayList.get(i)[name_to_city]);
                realmObject.setHighlight_to_city(arrayList.get(i)[highlight_to_city]);
                realmObject.setId_to_city(Integer.valueOf(arrayList.get(i)[id_to_city]));

                realmObject.setInfo(arrayList.get(i)[info]);

                realmObject.setFrom_date(arrayList.get(i)[from_date]);
                realmObject.setFrom_time(arrayList.get(i)[from_time]);
                realmObject.setFrom_info(arrayList.get(i)[from_info]);

                realmObject.setTo_date(arrayList.get(i)[to_date]);
                realmObject.setTo_time(arrayList.get(i)[to_time]);
                realmObject.setTo_info(arrayList.get(i)[to_info]);

                realmObject.setPrice(Integer.valueOf(arrayList.get(i)[price]));
                realmObject.setBus_id(Integer.valueOf(arrayList.get(i)[bus_id]));
                realmObject.setReservation_count(Integer.valueOf(arrayList.get(i)[reservation_count]));
            }

            realm.commitTransaction();

            } finally {
                realm.close();
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            if (BuildConfig.USE_LOG) {Log.d("The cache is written to the Realm database");}
            super.onPostExecute(result);
        }
    }

    // Caching the query in the SQLite database
    class CacheSQLite extends AsyncTask<Void, Void, Void> {

        @Override
        protected Void doInBackground(Void... params) {
            SQLiteDatabase db = dbHelper.getWritableDatabase();

            ContentValues values = new ContentValues();
            ArrayList<String[]> arrayList = new JSONParsing().examineJSONObj();

            db.delete(dbHelper.TABLE_NAME, null, null);
            for (int i = 0; i < arrayList.size(); i++){
                values.put(dbHelper.ID, arrayList.get(i)[id]);
                values.put(dbHelper.NAME_FROM_CITY, arrayList.get(i)[name_from_city]);
                values.put(dbHelper.HIGHLIGHT_FROM_CITY, arrayList.get(i)[highlight_from_city]);
                values.put(dbHelper.ID_FROM_CITY, arrayList.get(i)[id_from_city]);
                values.put(dbHelper.NAME_TO_CITY, arrayList.get(i)[name_to_city]);
                values.put(dbHelper.HIGHLIGHT_TO_CITY, arrayList.get(i)[highlight_to_city]);
                values.put(dbHelper.ID_TO_CITY, arrayList.get(i)[id_to_city]);
                values.put(dbHelper.INFO, arrayList.get(i)[info]);
                values.put(dbHelper.FROM_DATE, arrayList.get(i)[from_date]);
                values.put(dbHelper.FROM_TIME, arrayList.get(i)[from_time]);
                values.put(DBHelper.FROM_INFO, arrayList.get(i)[from_info]);
                values.put(DBHelper.TO_DATE, arrayList.get(i)[to_date]);
                values.put(dbHelper.TO_TIME, arrayList.get(i)[to_time]);
                values.put(dbHelper.TO_INFO, arrayList.get(i)[to_info]);
                values.put(dbHelper.PRICE, arrayList.get(i)[price]);
                values.put(dbHelper.BUS_ID, arrayList.get(i)[bus_id]);
                values.put(dbHelper.RESERVATION_COUNT, arrayList.get(i)[reservation_count]);

                db.insert(dbHelper.TABLE_NAME, null, values);
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            if (BuildConfig.USE_LOG) {Log.d("The cache is written to the SQLite database");}
            super.onPostExecute(result);
        }
    }
}

问题是，如果您在使用其中一个 AsyncTask 之后调用 onPause 方法（即使在最后一个完成之后）。错误文本如下：

    02-01 03:52:39.581 1688-1688/tanat.androidtesttask E/UncaughtException: java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.FileOutputStream android.content.Context.openFileOutput(java.lang.String, int)' on a null object reference
                                                                                at android.content.ContextWrapper.openFileOutput(ContextWrapper.java:183)
at tanat.androidtesttask.d.b.a(Unknown Source)
at tanat.androidtesttask.fragments.ListFragment.onListItemClick(Unknown Source)
at android.app.ListFragment$2.onItemClick(ListFragment.java:160)
at android.widget.AdapterView.performItemClick(AdapterView.java:310)
at android.widget.AbsListView.performItemClick(AbsListView.java:1145)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:3042)
at android.widget.AbsListView.onTouchUp(AbsListView.java:3891)
at android.widget.AbsListView.onTouchEvent(AbsListView.java:3656)
at android.view.View.dispatchTouchEvent(View.java:9294)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2547)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2240)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at com.android.internal.policy.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2403)
at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1737)
at android.app.Activity.dispatchTouchEvent(Activity.java:2765)
at com.android.internal.policy.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2364)
at android.view.View.dispatchPointerEvent(View.java:9514)
at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4230)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4096)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3642)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3695)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3661)
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3787)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3669)
at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3844)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3642)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3695)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3661)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3669)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3642)
at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:5922)
at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:5896)
at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:5857)
at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:6025)
at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185)
at android.os.MessageQueue.nativePollOnce(Native Method)
at android.os.MessageQueue.ne
    02-01 03:52:39.586 1688-1688/tanat.androidtesttask E/AndroidRuntime: FATAL EXCEPTION: main
Process: tanat.androidtesttask, PID: 1688
java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.FileOutputStream android.content.Context.openFileOutput(java.lang.String, int)' on a null object reference
at android.content.ContextWrapper.openFileOutput(ContextWrapper.java:183)
at tanat.androidtesttask.d.b.a(Unknown Source)
at tanat.androidtesttask.fragments.ListFragment.onListItemClick(Unknown Source)
at android.app.ListFragment$2.onItemClick(ListFragment.java:160)
at android.widget.AdapterView.performItemClick(AdapterView.java:310)
at android.widget.AbsListView.performItemClick(AbsListView.java:1145)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:3042)
at android.widget.AbsListView.onTouchUp(AbsListView.java:3891)
at android.widget.AbsListView.onTouchEvent(AbsListView.java:3656)
at android.view.View.dispatchTouchEvent(View.java:9294)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2547)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2240)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2553)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2254)
at com.android.internal.policy.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2403)
at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1737)
at android.app.Activity.dispatchTouchEvent(Activity.java:2765)
at com.android.internal.policy.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2364)
at android.view.View.dispatchPointerEvent(View.java:9514)
at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4230)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4096)
at 
android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185)
at android.os.MessageQueue.

我不明白问题出在哪里，因为没有一个 asyncTasks 使用 onPause 使用的任何东西。请帮助理解。

有一个代码：

    import android.Manifest;
    import android.app.Activity;
    import android.app.AlertDialog;
    import android.content.Context;
    import android.content.DialogInterface;
    import android.content.pm.PackageManager;
    import android.os.Bundle;
    import android.os.Environment;
    import android.support.v4.app.ActivityCompat;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.widget.Toast;
    import com.google.firebase.analytics.FirebaseAnalytics;
    import tanat.androidtesttask.R;
    import tanat.androidtesttask.errorreporter.GetLogs;
    import tanat.androidtesttask.utils.LoadLocalData;
    import tanat.androidtesttask.utils.SendEMail;

    public class MainActivity extends Activity {

        private FirebaseAnalytics mFirebaseAnalytics;
        public Context context;

        @Override
        public void onCreate(Bundle savedInstanceState) {
            setContentView(R.layout.activity_main);

            // Obtain the FirebaseAnalytics instance.
            mFirebaseAnalytics = FirebaseAnalytics.getInstance(this);

            context = MainActivity.this;
            super.onCreate(savedInstanceState);
        }

        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            getMenuInflater().inflate(R.menu.menu, menu);
            return true;
        }

        public String LOG_FILE_NAME = "logs";

        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            String action = "";

            int i = item.getItemId();
            //
            if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {

            if (i == R.id.save_logs) {
                    if (isCheckPermission(1)) {
                        saveLogs();
                    }
            } else if (i == R.id.send_logs) {
                if (isCheckPermission(2)) {
                    new SendEMail(MainActivity.this).send(LOG_FILE_NAME);
                    tanat.androidtesttask.errorreporter.Log.d("Permission granted, file sending");
                } else {
    ///
                }
            }
            } else {
                action = "Insert a memory card";
            }
            Toast.makeText(this, action, Toast.LENGTH_SHORT).show();
            return super.onOptionsItemSelected(item);
        }

        private boolean isCheckPermission(int i) {
            if (i == 1) {
                if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) !=
                        PackageManager.PERMISSION_GRANTED) {

                    // Should we show an explanation?
                    if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                        showMessageOKCancel("Requires write permission to save logs to file");
                        return false;
                    }

                    // No explanation needed, we can request the permission.
                    ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.WRITE_EXTERNAL_STORAGE},
                            PERMISSIONS_REQUEST);

                    return false;
                    // MY_PERMISSIONS_REQUEST is an
                    // app-defined int constant. The callback method gets the
                    // result of the request.
                }
                return true;
            } else if (i == 2) {
                if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) !=
                        PackageManager.PERMISSION_GRANTED) {

                    // Should we show an explanation?
                    if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.READ_EXTERNAL_STORAGE)) {
                        showMessageOKCancel("Requires read permission to transfer file");
                        return false;
                    }
                    ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.READ_EXTERNAL_STORAGE},
                            PERMISSIONS_REQUEST);

                    return false;
                }

                return true;
            }
            return false;
        }

        private void showMessageOKCancel(String message) {
            new AlertDialog.Builder(MainActivity.this)
                    .setMessage(message)
                    .setPositiveButton("OK", listener)
                    .setNegativeButton("Cancel", listener)
                    .create()
                    .show();
        }

        final private int PERMISSIONS_REQUEST = 7;

        DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() {

            final int BUTTON_NEGATIVE = -2;
            final int BUTTON_POSITIVE = -1;

            @Override
            public void onClick(DialogInterface dialog, int which) {
                switch (which) {
                    case BUTTON_NEGATIVE:
                        // int which = -2
                        dialog.dismiss();
                        break;

                    case BUTTON_POSITIVE:
                        // int which = -1
                        ActivityCompat.requestPermissions(
                                MainActivity.this, new String[]{
                                        android.Manifest.permission.WRITE_EXTERNAL_STORAGE,
                                        android.Manifest.permission.READ_EXTERNAL_STORAGE},
                                PERMISSIONS_REQUEST);
                        dialog.dismiss();
                        break;
                }
            }
        };

    /*    Handler handler = new Handler(){
            @Override
            public void handleMessage(Message msg){
                LoadLocalData loadSD = new LoadLocalData(MainActivity.this);
                loadSD.writeFileSD(LOG_FILE_NAME, GetLogs.get());
                Toast.makeText(MainActivity.this, "Logs save", Toast.LENGTH_SHORT).show();
            }
        };*/

        @Override
        public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
            switch (requestCode) {
                case PERMISSIONS_REQUEST: {
                    // If request is cancelled, the result arrays are empty.
                    if (grantResults.length > 0
                            && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                        // permission was granted!
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        //Toast.makeText(this, "Permission on write storage granted", Toast.LENGTH_SHORT).show();
                            saveLogs();
                        }
                        if (grantResults[1] == PackageManager.PERMISSION_GRANTED) {
                            Toast.makeText(this, "Permission on read storage granted.", Toast.LENGTH_SHORT).show();
                        }

                    } else {

                        // permission denied, boo! Disable the
                        // functionality that depends on this permission.
                    }
                    return;
                }

                // other 'case' lines to check for other
                // permissions this app might request.
            }
        }

//метод который сохраняет логи
        public void saveLogs (){
            LoadLocalData loadSD = new LoadLocalData(MainActivity.this);
            loadSD.writeFileSD(LOG_FILE_NAME, GetLogs.get());
            Toast.makeText(this, "Logs save", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onDestroy() {
        //    Log.d("Logs","Logs: " + GetLogs.get());

            super.onDestroy();
        }
    }

在第一次尝试保存日志时，它会请求将数据写入存储卡的权限，如果获得，它会写入文件，然后立即崩溃并出现错误：

E/UncaughtException: java.lang.RuntimeException: Failure delivering result ResultInfo{who=@android:requestPermissions:, request=7, result=-1, data=Intent { act=android.content.pm.action.REQUEST_PERMISSIONS (has extras) }} to activity {tanat.androidtesttask/tanat.androidtesttask.activity.MainActivity}: java.lang.ArrayIndexOutOfBoundsException: length=1; index=1
                         at android.app.ActivityThread.deliverResults(ActivityThread.java:3699)
                         at android.app.ActivityThread.handleSendResult(ActivityThread.java:3742)
                         at android.app.ActivityThread.-wrap16(ActivityThread.java)
                         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1393)
                         at android.os.Handler.dispatchMessage(Handler.java:102)
                         at android.os.Looper.loop(Looper.java:148)
                         at android.app.ActivityThread.main(ActivityThread.java:5417)
                         at java.lang.reflect.Method.invoke(Native Method)
                         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
                      Caused by: java.lang.ArrayIndexOutOfBoundsException: length=1; index=1
                         at tanat.androidtesttask.activity.MainActivity.onRequestPermissionsResult(Unknown Source)
                         at android.app.Activity.dispatchRequestPermissionsResult(Activity.java:6553)
                         at android.app.Activity.dispatchActivityResult(Activity.java:6432)
                         at android.app.ActivityThread.deliverResults(ActivityThread.java:3695)
                         at android.app.ActivityThread.handleSendResult(ActivityThread.java:3742) 
                         at android.app.ActivityThread.-wrap16(ActivityThread.java) 
                         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1393) 
                         at android.os.Handler.dispatchMessage(Handler.java:102) 
                         at android.os.Looper.loop(Looper.java:148) 
                         at android.app.ActivityThread.main(ActivityThread.java:5417) 
                         at java.lang.reflect.Method.invoke(Native Method) 
                         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
                         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: tanat.androidtesttask, PID: 2022
                  java.lang.RuntimeException: Failure delivering result ResultInfo{who=@android:requestPermissions:, request=7, result=-1, data=Intent { act=android.content.pm.action.REQUEST_PERMISSIONS (has extras) }} to activity {tanat.androidtesttask/tanat.androidtesttask.activity.MainActivity}: java.lang.ArrayIndexOutOfBoundsException: length=1; index=1
                      at android.app.ActivityThread.deliverResults(ActivityThread.java:3699)
                      at android.app.ActivityThread.handleSendResult(ActivityThread.java:3742)
                      at android.app.ActivityThread.-wrap16(ActivityThread.java)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1393)
                      at android.os.Handler.dispatchMessage(Handler.java:102)
                      at android.os.Looper.loop(Looper.java:148)
                      at android.app.ActivityThread.main(ActivityThread.java:5417)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
                   Caused by: java.lang.ArrayIndexOutOfBoundsException: length=1; index=1
                      at tanat.androidtesttask.activity.MainActivity.onRequestPermissionsResult(Unknown Source)
                      at android.app.Activity.dispatchRequestPermissionsResult(Activity.java:6553)
                      at android.app.Activity.dispatchActivityResult(Activity.java:6432)
                      at android.app.ActivityThread.deliverResults(ActivityThread.java:3695)
                      at android.app.ActivityThread.handleSendResult(ActivityThread.java:3742) 
                      at android.app.ActivityThread.-wrap16(ActivityThread.java) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1393) 
                      at android.os.Handler.dispatchMessage(Handler.java:102) 
                      at android.os.Looper.loop(Looper.java:148) 
                      at android.app.ActivityThread.main(ActivityThread.java:5417) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 

在随后的发射中（当已经获得许可时）没有问题。如果您删除数据保存方法，只需放一个 toast - 它可以工作（更准确地说，它是这样工作的，但它不会随着 toast 而退出）。我读到权限对话框似乎在一个单独的线程中，我试图通过hander保存它（虽然这也是废话，然后toast也不起作用），但无济于事。请告诉我如何解决这个问题？

先生们好日子。通常，任务是获取应用程序执行日志并通过邮件将它们发送给开发人员。我认为发送会有问题，但日志不会有问题。有一个代码：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class GetLogs {

    public static String get(){
        StringBuilder builder = new StringBuilder();
        try {
            Process process = Runtime.getRuntime().exec("logcat -d all");

            BufferedReader bufferedReader = new BufferedReader(
                    new InputStreamReader(process.getInputStream()));

            String line;
            while ((line = bufferedReader.readLine()) != null) {
                builder.append(line + "\n");
            }
        } catch (IOException e){
            Log.d("Error getting logs");
        }
        return builder.toString();
    }
}

该类只是捕获并返回日志，问题在于它捕获它们的标签。“logcat -d all”应该捕获所有带有d标签的日志，但是我手动输出的那些日志原则上不会捕获。我这样输出它（好吧，你永远不知道）：

Log.d("MyLog","TEST");

上面的方法返回以下内容：

    --------- beginning of system
01-26 08:42:37.797  1813  1827 E ActivityThread: Failed to find provider info for com.google.android.gms.chimera
    --------- beginning of main
01-26 08:42:37.797  1813  1827 I chatty  : uid=10080(tanat.androidtesttask) expire 8 lines
01-26 08:42:37.805  1813  1829 I chatty  : uid=10080(tanat.androidtesttask) expire 1 line
01-26 08:42:37.900  1813  1831 I chatty  : uid=10080(tanat.androidtesttask) expire 24 lines
01-26 08:42:39.136  1813  1832 I chatty  : uid=10080(tanat.androidtesttask) expire 9 lines
01-26 08:43:19.769  1813  1848 I chatty  : uid=10080(tanat.androidtesttask) expire 15 lines
01-26 08:43:20.075  1813  1813 I chatty  : uid=10080(tanat.androidtesttask) expire 6 lines
01-26 08:57:52.638  1974  1974 I chatty  : uid=10080(tanat.androidtesttask) expire 27 lines
01-26 08:57:52.670  1974  1988 E ActivityThread: Failed to find provider info for com.google.android.gms.chimera
01-26 08:57:52.670  1974  1988 I chatty  : uid=10080(tanat.androidtesttask) expire 8 lines
01-26 08:57:52.678  1974  1990 I chatty  : uid=10080(tanat.androidtesttask) expire 1 line
01-26 08:57:52.699  1974  1992 I chatty  : uid=10080(tanat.androidtesttask) expire 39 lines
01-26 08:57:53.029  1974  1993 I chatty  : uid=10080(tanat.androidtesttask) expire 9 lines
01-26 09:02:55.283  2073  2073 I chatty  : uid=10080(tanat.androidtesttask) expire 17 lines
01-26 09:02:55.317  2073  2087 E ActivityThread: Failed to find provider info for com.google.android.gms.chimera
01-26 09:02:55.317  2073  2087 I chatty  : uid=10080(tanat.androidtesttask) expire 8 lines
01-26 09:02:55.322  2073  2089 I chatty  : uid=10080(tanat.androidtesttask) expire 1 line
01-26 09:02:55.347  2073  2091 I chatty  : uid=10080(tanat.androidtesttask) expire 3 lines
     --------- beginning of crash
01-26 09:02:55.355  2073  2073 E AndroidRuntime: FATAL EXCEPTION: main
01-26 09:02:55.355  2073  2073 E AndroidRuntime: Process: tanat.androidtesttask, PID: 2073
01-26 09:02:55.355  2073  2073 E AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{tanat.androidtesttask/tanat.androidtesttask.activity.MainActivity}: java.lang.ArithmeticException: divide by zero
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at android.app.ActivityThread.-wrap11(ActivityThread.java)
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at android.os.Handler.dispatchMessage(Handler.java:102)
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at android.os.Looper.loop(Looper.java:148)
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at android.app.ActivityThread.main(ActivityThread.java:5417)
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at java.lang.reflect.Method.invoke(Native Method)
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
01-26 09:02:55.355  2073  2073 E AndroidRuntime: Caused by: java.lang.ArithmeticException: divide by zero
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at tanat.androidtesttask.activity.MainActivity.onCreate(Unknown Source)
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at android.app.Activity.performCreate(Activity.java:6237)
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
01-26 09:02:55.355  2073  2073 E AndroidRuntime:    ... 9 more
01-26 09:03:15.533  2102  2102 I chatty  : uid=10080(tanat.androidtesttask) expir

事实上，如果您添加更多我编写的日志，这就是您所需要的。请告诉我，怎么做？

再会。我想连接到 Crashlytics 项目，我跟着办公室。指令但抛出错误：

Error:Execution failed for task ':app:processDebugGoogleServices'.
> Please fix the version conflict either by updating the version of the google-services plugin (information about the latest version is available at https://bintray.com/android/android-tools/com.google.gms.google-services/) or updating the version of com.google.android.gms to 11.4.2.

我无法弄清楚版本不兼容的确切位置。build.gradle 项目代码

buildscript {
    repositories {
        google()
        jcenter()
        mavenCentral()
        maven {
            url 'https://maven.fabric.io/public'
        }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'
        classpath 'com.jakewharton:butterknife-gradle-plugin:8.8.1'

        classpath 'com.google.gms:google-services:3.1.2'
        classpath 'io.fabric.tools:gradle:1.24.4'
    }
}

allprojects {
    repositories {
        google()
        jcenter()
        maven {
            url 'https://maven.google.com/'
        }
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

build.gradle 应用代码

apply plugin: 'com.android.application'
apply plugin: 'com.google.gms.google-services'
apply plugin: 'io.fabric'

android {
    compileSdkVersion 26
    defaultConfig {
        applicationId "tanat.androidtesttask"
        minSdkVersion 15
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    implementation 'com.android.support:support-v4:26.1.0'
    implementation 'com.android.support:recyclerview-v7:26.1.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'

    implementation 'com.jakewharton:butterknife:8.8.1'
    annotationProcessor 'com.jakewharton:butterknife-compiler:8.8.1'

    compile('com.crashlytics.sdk.android:crashlytics:2.7.1@aar') {
        transitive = true
    }
    compile 'com.google.firebase:firebase-core:11.8.0'
}

请帮我找到解决方案。

有一个接收片段数据的类

package tanat.androidtesttask.utils;

import android.content.Context;
import java.util.ArrayList;
import tanat.androidtesttask.activity.MainActivity;

public class LoadAllData {

    private final Context context;

    public LoadAllData(Context context) {
        this.context = context;
    }

    public ArrayList loadDemoData (Context context, int numberOfDownloads){
        String jsonStr = "";

        if (numberOfDownloads == 0) {
            jsonStr = loadLocalData(context);
            //делаем проверку на наличие локальной базы
            if (jsonStr == null || jsonStr.equals("")) {
                jsonStr = loadInetData();
            }
        } else {
            jsonStr = loadInetData();
        }

        ArrayList demoData = new JSONParsing().examineJSONDemoString(jsonStr);
        return demoData;
    }

    public String loadLocalData (Context context) {
        LoadLocalData loadLocalData;
        loadLocalData = new LoadLocalData(context);
        return loadLocalData.readFile();
    }

    public void pullLocalData (Context context, String localJsonStr) {
        LoadLocalData loadLocalData;
        loadLocalData = new LoadLocalData(context);
        loadLocalData.writeFile(localJsonStr);
    }

    public String loadInetData (){
        return MainActivity.loadData();
    }
}

但问题是通过 MainActivity.loadData() 的 loadInetData 方法加载数据没有正确实现（我什至会说 bydlocode）。此方法应从应用程序启动后立即创建的服务接收数据，并以流的形式从网络加载数据，并且片段应在数据加载期间旋转进度对话框。但我无法在第二天实施。

片段代码：package tanat.androidtesttask.fragments；

import android.app.DialogFragment;
import android.app.PendingIntent;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Build;
import android.os.Bundle;
import android.os.IBinder;
import android.support.annotation.RequiresApi;
import android.support.v4.widget.SwipeRefreshLayout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import java.util.ArrayList;
import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.OnClick;
import butterknife.Unbinder;

import tanat.androidtesttask.activity.InfoRoutActivity;
import tanat.androidtesttask.activity.MainActivity;
import tanat.androidtesttask.R;
import tanat.androidtesttask.service.ConectService;
import tanat.androidtesttask.service.TestService;
import tanat.androidtesttask.utils.LoadAllData;

public class ListFragment extends android.app.ListFragment implements SwipeRefreshLayout.OnRefreshListener{

    // unbilder для роботы butterknife с фрагментом

    private View rootView;
    private DialogFragment dialogFragment;

    @BindView(R.id.refresh) SwipeRefreshLayout swipeRefreshLayout;
    @BindView(R.id.standart_layout) LinearLayout contentLayout;
    @BindView(R.id.error_layout) LinearLayout errorLayout;
    @BindView(R.id.errorTextView) TextView errorTextView;

    //кнопка для обновления в случае ошибки
    @OnClick(R.id.refreshButton)
    void onRefreshClick() {
        onRefresh();
    }

    //подключаем мой фрагмент
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        rootView = inflater.inflate(R.layout.fragment_item, null);
        ButterKnife.bind(this, rootView);

        dialogFragment = new AlterDialog();
        swipeRefreshLayout.setOnRefreshListener(this);

        return rootView;
    }

    private ArrayList data = null;

    @Override
    public void onStart() {
        super.onStart();
        onRefresh();
    }

    //вешаем слушатель на нажатие итема фрагмента
    @RequiresApi(api = Build.VERSION_CODES.M)
    @Override
    public void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);

        //передаем позицию елемента в второе активити
        //создаем интент
        Intent intent = new Intent(ListFragment.this.getContext(), InfoRoutActivity.class);
        //записываем в него ключ и позицию
        intent.putExtra("position", position);
        //передаем
        startActivity(intent);
    }

    int numberOfDownloads = 0;

    //свайп вниз для обновления
    @Override
    public void onRefresh() {
        // начинаем показывать прогресс
        swipeRefreshLayout.setRefreshing(true);

        // вызываем загрузку данных 
        LoadAllData loadAllData = new LoadAllData(getActivity());
        data = loadAllData.loadDemoData(getActivity(), numberOfDownloads);

        numberOfDownloads++;

        if(data.size() > 0){
            // данные для списка есть
            // теперь проверим правильно ли была выполнена сетевая операция
            if(data.get(0).toString().equals("false")){
                // сетевая операция не прошла
                // меняем видимость layout так, что б не было видно рабочего layout и был виден
                // layout ошибки и вводим текст ошибки в textView
                contentLayout.setVisibility(View.INVISIBLE);
                errorLayout.setVisibility(View.VISIBLE);
                errorTextView.setText(data.get(1).toString());
            } else {
                //если сетевая операция прошла успешно
                errorLayout.setVisibility(View.INVISIBLE);
                contentLayout.setVisibility(View.VISIBLE);
                // создаем список
                createdList();
            }
        } else {
            //если данных списка нету
            errorLayout.setVisibility(View.INVISIBLE);
            contentLayout.setVisibility(View.VISIBLE);
            // создаем список (ListFragment автоматически выведет заданое сообщение)
            createdList();
        }

        // прячем прогресс
        swipeRefreshLayout.postDelayed(new Runnable() {
            @Override
            public void run() {
                swipeRefreshLayout.setRefreshing(false);
                //либо используем наш класс
        //        dialogFragment.dismiss();
            }
        }, 300);
    }

    private ArrayAdapter<String> adapter;

    // метод создание списка
    public void createdList(){
        adapter = new ArrayAdapter<String>(getActivity(),
                android.R.layout.simple_list_item_1, data);
        setListAdapter(adapter);
    }
}

服务代码：

package tanat.androidtesttask.service;

import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Binder;
import android.os.IBinder;
import android.util.Log;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.concurrent.ExecutionException;

public class ConectService extends Service {

    final String LOG_TAG = "MyLog";
    private static Context context;

    @Override
    public IBinder onBind(Intent intent) {
        return binder;
    }

    public void onCreate() {
        super.onCreate();
        Log.d(LOG_TAG, "onCreate");
    }

    private final IBinder binder = new LocalBinder();
    private static String inetJsonStr = "";

    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d(LOG_TAG, "onStartCommand");
        someTask();
        return super.onStartCommand(intent, flags, startId);
    }

    public void onDestroy() {
        super.onDestroy();
        Log.d(LOG_TAG, "onDestroy");
    }

    public void someTask() {
        GetTask getTask = new GetTask();
        getTask.execute();
        try {
            inetJsonStr = getTask.get();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (ExecutionException e) {
            e.printStackTrace();
        }
    }

    public String getInetJsonStr() {
        if (inetJsonStr.equals("")){

            return null;
        } else {
            return inetJsonStr;
        }
    }

    public class LocalBinder extends Binder {
        public ConectService getService() {
            return ConectService.this;
        }
    }

    private class GetTask extends AsyncTask<Void, Void, String> {

        @Override
        protected String doInBackground(Void... params) {
            String strJson = "";
            InputStream inputStream;

            HttpURLConnection urlConnection = null;
            BufferedReader reader = null;

            // получаем данные с внешнего ресурса и переделываем в строку
            try {
                URL url = new URL("http://projects.gmoby.org/web/index.php/api/trips?from_date=2016-01-01&to_date=2018-03-01");

                urlConnection = (HttpURLConnection) url.openConnection();
                urlConnection.setRequestMethod("GET");
                urlConnection.connect();

                inputStream = url.openConnection().getInputStream();
                StringBuffer buffer = new StringBuffer();
                reader = new BufferedReader(new InputStreamReader(inputStream));

                String line;
                while ((line = reader.readLine()) != null) {
                    buffer.append(line);
                }
                Log.d(LOG_TAG, "strJson not null");
                strJson = buffer.toString();
            } catch (Exception e) {
                e.printStackTrace();
                strJson = e.getMessage();
                Log.d(LOG_TAG, strJson);
            }

            return strJson;
        }
    }
}

这项任务显然不是一件容易的事，我真的希望会有人为此想破脑袋（我已经破了我的）。链接到git 在此先感谢。

有以下类用于写入和读取文件（手机内部存储器）

import android.content.Context;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

public class LoadData {

    public void loadData (){
    }

    // переменная в которой записано название файла что представляет собой локальную строку json
    // или локальную базу
    private String FILENAME = "jsonmytest";

    //метод для сохранение строки json в файл (создание локальной базы)
    protected void write(String answer) {
        try {
            // отрываем поток для записи
            BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(openFileOutput(FILENAME, Context.MODE_PRIVATE)));
            // пишем данные
            bw.write(answer);
            // закрываем поток
            bw.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    // метод для чтения строки json из файла
    public String readFile() {
        String str = "";
        try {
            // открываем поток для чтения
            BufferedReader br = new BufferedReader(new InputStreamReader(openFileInput(FILENAME)));
            // читаем содержимое
            str = br.readLine();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return str;
    }
}

openFileOutput 和 openFileInput 方法以红色突出显示，并且在悬停时写入无法解析方法“openFileInput(java.long.String)”自然会导入所有库。

在 MainActivity 类中，read 和 write 方法的代码完全相同，但这需要在另一个类中加载。请帮忙，我不知道出了什么问题。

下午好，我正在为一名课程工作者用 Java 制作一个 Web 应用程序。出现技术问题。我无法将带有对象的 ArrayList 中的数据输出到将在浏览器页面上的表中。有数据的类代码：

package tanat.servlet;

import java.io.IOException;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import tanat.beans.IceFloe;
import tanat.database.DBUtils;
import tanat.database.MySQLConnUtils;



@WebServlet(urlPatterns = { "/icefloelist" })
public class IceFloeList extends HttpServlet {

    private static final long serialVersionUID = 1L;

    public IceFloeList() {
        super();
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

   //     Connection conn = MyUtils.getStoredConnection(request);
    Connection conn = null;
        String errorString = null;
        List<IceFloe> listfloe = null;

        conn = MySQLConnUtils.getDBConnection();

        try {
            listfloe = DBUtils.queryIceFloe(conn);
        } catch (SQLException e) {
            e.printStackTrace();
            errorString = e.getMessage();
        } 
        // Сохранить информацию в request attribute перед тем как forward к views.
        request.setAttribute("errorString", errorString);
        request.setAttribute("listfloe", listfloe);

        // проверял, в консоль данные идут
        for (int i=0; i< listfloe.size(); i++) {
            System.out.println(listfloe.get(i).getId());
            System.out.println(listfloe.get(i).getNameIceFloe());
            System.out.println(listfloe.get(i).getNumberOfFishermen());
            System.out.println("\n");
        }

        // Forward к /views/productListView.jsp
        RequestDispatcher dispatcher = request.getRequestDispatcher("/views/iceFloeListView.jsp");
        // и так пробывал
//      RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/views/iceFloeListView.jsp");
        dispatcher.forward(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

jsp页面代码

<%@ page language="java" contentType="text/html; charset=UTF-8"
 pageEncoding="UTF-8"%>

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>SalvageService</title>
    <link rel="stylesheet" href="css/style.css">
</head>
<body>

    <div class="navcont" align="center">
        <div class="nav">
            <ul>
                <li><a href="index.html">Главная</a></li>
                <li><a href="ships.html">Корабли</a></li>
                <li><a href="#">Рыбаки</a></li>
                <li><a href="#">Море</a></li>
            </ul>
        </div>
    </div>
    <main>

<table border="1" cellpadding="5" cellspacing="1" >
       <tr>
          <th>Code</th>
          <th>Name</th>
          <th>Price</th>
          <th>Edit</th>
          <th>Delete</th>
       </tr>
       <c:forEach items="${listfloe}" var="iceFloe">
          <tr>
             <td>${iceFloe.id}</td>
             <td>${iceFloe.name}</td>
             <td>${iceFloe.numberOfFishermen}</td>
             <td>
                <a href="editProduct?code=${iceFloe.id}">Edit</a>
             </td>
             <td>
                <a href="deleteProduct?code=${iceFloe.id}">Delete</a>
             </td>
          </tr>
       </c:forEach>
    </table>
    </main>

    <footer>
    <hr>
    <p align="center">
        <small>
        <time>01-2017</time> © Kravchenko Pavel
       </small>
    </p>
    </footer>

</body>
</html>

也就是应该把数据代入表中，但是在控制台中并没有出现这种情况，它写了以下内容，但我认为这不是错误

янв 11, 2018 9:33:29 AM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:SalvageService' did not find a matching property.
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server version:        Apache Tomcat/8.0.36
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server built:          Jun 9 2016 13:55:50 UTC
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server number:         8.0.36.0
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Name:               Windows 10
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Version:            10.0
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Architecture:          amd64
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Java Home:             C:\Program Files\Java\jre1.8.0_151
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Version:           1.8.0_151-b12
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Vendor:            Oracle Corporation
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_BASE:         D:\Developer\JavaScript\.metadata\.plugins\org.eclipse.wst.server.core\tmp1
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_HOME:         C:\Tomcat
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.base=D:\Developer\JavaScript\.metadata\.plugins\org.eclipse.wst.server.core\tmp1
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.home=C:\Tomcat
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dwtp.deploy=D:\Developer\JavaScript\.metadata\.plugins\org.eclipse.wst.server.core\tmp1\wtpwebapps
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.endorsed.dirs=C:\Tomcat\endorsed
янв 11, 2018 9:33:29 AM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dfile.encoding=Cp1251
янв 11, 2018 9:33:29 AM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files\Java\jre1.8.0_151\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:/Program Files/Java/jre1.8.0_151/bin/server;C:/Program Files/Java/jre1.8.0_151/bin;C:/Program Files/Java/jre1.8.0_151/lib/amd64;C:\ProgramData\Oracle\Java\javapath;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\Program Files\Git\cmd;C:\Server\web\apache\bin;C:\Server\web\mysql\bin;;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Users\TaNaT\.dnx\bin;C:\Program Files\Microsoft DNX\Dnvm\;C:\Users\TaNaT\AppData\Local\Microsoft\WindowsApps;C:\Server\web\apache\bin;C:\Server\web\mysql\bin;;C:\Users\TaNaT\Desktop;;.
янв 11, 2018 9:33:29 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-nio-8080"]
янв 11, 2018 9:33:30 AM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
INFO: Using a shared selector for servlet write/read
янв 11, 2018 9:33:30 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["ajp-nio-8009"]
янв 11, 2018 9:33:30 AM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
INFO: Using a shared selector for servlet write/read
янв 11, 2018 9:33:30 AM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 1545 ms
янв 11, 2018 9:33:30 AM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
янв 11, 2018 9:33:30 AM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/8.0.36
янв 11, 2018 9:33:34 AM org.apache.jasper.servlet.TldScanner scanJars
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
янв 11, 2018 9:33:38 AM org.apache.jasper.servlet.TldScanner scanJars
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
янв 11, 2018 9:33:38 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-nio-8080"]
янв 11, 2018 9:33:38 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["ajp-nio-8009"]
янв 11, 2018 9:33:38 AM org.apache.catalina.startup.Catalina start
INFO: Server startup in 7951 ms
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
1
scandinavi
4


2
sibir
7

大多数关于启动服务器的信息，但也许我错过了一些东西，最后证明数据在那里。如果需要 - respasitorium https://bitbucket.org/pahan-titan/salvageservice 请帮助，剩下的时间不多了）提前致谢。

我正在用 Java 为学期论文编写一个 Web 应用程序。启动时出现错误

SEVERE: Servlet.service() for servlet [tanat.servlet.IceFloeList] in context with path [/SalvageService] threw exception
java.lang.NullPointerException
    at tanat.database.DBUtils.queryIceFloe(DBUtils.java:19)
    at tanat.servlet.IceFloeList.doGet(IceFloeList.java:47)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)

发誓，因为我了解这门课

package tanat.database;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import tanat.beans.IceFloe;

public class DBUtils {

    public static List<IceFloe> queryIceFloe(Connection conn) throws SQLException {
        String sql = "SELECT `id`, `name_ice_floe`, ` number_of_fishermen` "
                + "FROM ice_floe ORDER BY 'number_of_fishermen' DESC;";

        PreparedStatement pstm = conn.prepareStatement(sql);  //на эту строку ругается
        ResultSet rs = pstm.executeQuery();
        List<IceFloe> list = new ArrayList<IceFloe>();

//пробывал через статмент ничего не меняеться
//      Statement statement = conn.createStatement();
//      ResultSet rs = statement.executeQuery(sql);

        while (rs.next()) {
            int id = rs.getInt("ID");
            String name = rs.getString("Name");
            int numberOfFishermen = rs.getInt("NumberOfFishermen");
            IceFloe iceFloe = new IceFloe();
            iceFloe.setId(id);
            iceFloe.setNameIceFloe(name);
            iceFloe.setNumberOfFishermen(numberOfFishermen);
            list.add(iceFloe);
        }
        return list;
    }

    public static IceFloe findIceFloe(Connection conn, String code) throws SQLException {
        String sql = "Select a.Code, a.Name, a.Price from Product a where a.Code=?";

        PreparedStatement pstm = conn.prepareStatement(sql);
        pstm.setString(1, code);

        ResultSet rs = pstm.executeQuery();

        while (rs.next()) {
            String name = rs.getString("Name");
            int numberOfFishermen = rs.getInt("NumberOfFishermen");
            IceFloe iceFloe = new IceFloe();
            iceFloe.setNameIceFloe(name);
            iceFloe.setNumberOfFishermen(numberOfFishermen);
            return iceFloe;
        }
        return null;
    }

    public static void updateIceFloe(Connection conn, IceFloe iceFloe) throws SQLException {
        String sql = "Update Product set Name =?, Price=? where Code=? ";

        PreparedStatement pstm = conn.prepareStatement(sql);

        pstm.setInt(1, iceFloe.getId());
        pstm.setString(2, iceFloe.getnameIceFloe());
        pstm.setInt(3, iceFloe.getNumberOfFishermen());

        pstm.executeUpdate();
    }

    public static void insertIceFloe(Connection conn, IceFloe iceFloe) throws SQLException {
        String sql = "Insert into Product(Code, Name,Price) values (?,?,?)";

        PreparedStatement pstm = conn.prepareStatement(sql);

        pstm.setInt(1, iceFloe.getId());
        pstm.setString(2, iceFloe.getnameIceFloe());
        pstm.setInt(3, iceFloe.getNumberOfFishermen());

        pstm.executeUpdate();
    }

    //удаление льдины
    //по идее нужно реализовать автоматическое удаление если количество рыбаков становиться равным 0
    public static void deleteIceFloe(Connection conn, String code) throws SQLException {
        String sql = "Delete From Product where Code= ?";

        PreparedStatement pstm = conn.prepareStatement(sql);

        pstm.setString(1, code);

        pstm.executeUpdate();
    }

}

请帮帮我，我已经摆弄了3天，剩下的时间不多了）如果您需要查看其他课程：https ://bitbucket.org/pahan-titan/salvageservice/src 提前谢谢

有以下代码：

package tanat.androidtesttask;

import android.app.DialogFragment;
import android.app.ListFragment;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.RequiresApi;
import android.support.v4.widget.SwipeRefreshLayout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;

public class MainList extends ListFragment implements SwipeRefreshLayout.OnRefreshListener{

    SwipeRefreshLayout mSwipeRefreshLayout;
    ArrayList data;
    DialogFragment dialogFragment;

    //подключаем мой фрагмент
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_item, null);

        dialogFragment = new MyDialog();

        mSwipeRefreshLayout = (SwipeRefreshLayout) view.findViewById(R.id.refresh);
        mSwipeRefreshLayout.setOnRefreshListener(this);
        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState){

        dialogFragment.show(getFragmentManager(), "");

        final Thread thread = new Thread(new Runnable() {

            @Override
            public void run() {
                data = new MainActivity().demo();
            }
        });
        thread.start();
        try {
            thread.join();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        dialogFragment.dismiss();


        //      dialogFragment.show(getFragmentManager(), "");

 //       data = new MainActivity().demo();

        //создаем лист фрагментов
        super.onActivityCreated(savedInstanceState);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),
                android.R.layout.simple_list_item_1, data);
        setListAdapter(adapter);
    }

    @Override
    public void onStart() {
        super.onStart();

    }

    //вешаем слушатель на нажатие фрагмента
    @RequiresApi(api = Build.VERSION_CODES.M)
    @Override
    public void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);

        //передаем позицию елемента в второе активити
        //создаем интент
        Intent intent = new Intent(MainList.this.getContext(), InfoRoutActivity.class);
        //записываем в него ключ и позицию
        intent.putExtra("position", position);
        //передаем
        startActivity(intent);
    }

    //свайп вниз для обновления
    @Override
    public void onRefresh() {
        // говорим о том, что собираемся начать
        Toast.makeText(getActivity(), "Обновляем", Toast.LENGTH_SHORT).show();
        // начинаем показывать прогресс
        mSwipeRefreshLayout.setRefreshing(true);
        // ждем 3 секунды и прячем прогресс
        mSwipeRefreshLayout.postDelayed(new Runnable() {
            @Override
            public void run() {
                mSwipeRefreshLayout.setRefreshing(false);
                // говорим о том, что собираемся закончить
                Toast.makeText(getActivity(),"обновили", Toast.LENGTH_SHORT).show();
            }
        }, 3000);
    }
}

这是片段类。当它被创建时，另一个片段被调用，它只是一个自定义的DialogFragment，就像一个进度对话框。和团队

data = new MainActivity().demo();

进入活动，从它到服务并加载 json，然后我们等到这个线程被执行并关闭进度对话框，然后我们从我们下载的数据中创建一个 ListFragment，至少按照预期，但是在这个命令上敲出以下错误

E/AndroidRuntime: FATAL EXCEPTION: Thread-130
                  Process: tanat.androidtesttask, PID: 1700
                  java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
                      at android.os.Handler.<init>(Handler.java:200)
                      at android.os.Handler.<init>(Handler.java:114)
                      at android.app.Activity.<init>(Activity.java:754)
                      at tanat.androidtesttask.MainActivity.<init>(MainActivity.java:0)
                      at tanat.androidtesttask.MainList$1.run(MainList.java:50)
                      at java.lang.Thread.run(Thread.java:818)

我已经尝试过使用 Handler 但我无法弄清楚在这种情况下如何正确使用它，我已经在互联网上翻找了 2 天但无济于事。请帮助提前谢谢。