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Accepted
David
Asked:2020-04-26 19:24:38 +0000 UTC2020-04-26 19:24:38 +0000 UTC

线程“主”java.lang.NullPointerException 中的异常

  • 772

这是Java代码：

package com.company;
import java.io.IOException;
import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.core5.http.ParseException;
import org.apache.hc.core5.http.io.entity.EntityUtils;


public class Main {
    static String sURL = "http://speller.yandex.net/services/spellservice";
    public static void main(String[] args) throws IOException {
        CloseableHttpResponse resp1 = null;
        try{
            CloseableHttpClient httpClient = HttpClients.createDefault();
            HttpGet httpGet = new HttpGet(sURL + "/checkText?text=мошына");
            resp1 = httpClient.execute(httpGet);
            System.out.println(EntityUtils.toString(resp1.getEntity()));
        } catch (IOException | ParseException e){
         e.printStackTrace();
        } finally {
            try {
                resp1.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

错误：

Exception in thread "main" java.lang.NullPointerException
    at com.company.Main.main(Main.java:24)

如何修复此错误？

java

1 个回答

  1. Best Answer

    在第 24 行，如果捕获成功，则调用其值为 null 的对象 (resp1) 的 close() 方法。
    执行以下操作：

    public class Main {
    static String sURL = "http://speller.yandex.net/services/spellservice";
    public static void main(String[] args) throws IOException {
        CloseableHttpResponse resp1 = null;
        try{
            CloseableHttpClient httpClient = HttpClients.createDefault();
            HttpGet httpGet = new HttpGet(sURL + "/checkText?text=мошына");
            resp1 = httpClient.execute(httpGet);
            System.out.println(EntityUtils.toString(resp1.getEntity()));
        } catch (IOException | ParseException e){
         e.printStackTrace();
        } finally {
            if (resp1 != null) {
              try {
                  resp1.close();
               } catch (IOException e) {
                  e.printStackTrace();
               }
            }
        }
    }
}
    • 2

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