主页 / 问题 / 696437
Accepted
Andrey
Asked:2020-07-22 22:40:06 +0000 UTC2020-07-22 22:40:06 +0000 UTC

依赖项没有被复制到 Maven

  • 772

在 maven 中构建项目时，依赖项不会复制到 jar 中，因此当您运行NoClassDefFoundError.
pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.example</groupId>
<artifactId>example</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
    <dependency>
        <groupId>com.1stleg</groupId>
        <artifactId>jnativehook</artifactId>
        <version>LATEST</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>LATEST</version>
        <scope>test</scope>
    </dependency>
</dependencies>
<build>
    <pluginManagement>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.5</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-jar-plugin</artifactId>
                <configuration>
                    <archive>
                        <manifest>
                            <addClasspath>true</addClasspath>
                            <classpathPrefix>lib/</classpathPrefix>
                            <mainClass>org.example.Main</mainClass>
                        </manifest>
                    </archive>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>2.1</version>
                <executions>
                    <execution>
                        <id>copy-dependencies</id>
                        <phase>package</phase>
                        <goals>
                            <goal>copy-dependencies</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${project.build.directory}/lib</outputDirectory>
                            <overWriteReleases>false</overWriteReleases>
                            <overWriteSnapshots>false</overWriteSnapshots>
                            <overWriteIfNewer>true</overWriteIfNewer>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </pluginManagement>
</build>

我还认为 maven-dependency-plugin 根本没有执行，因为在控制台的构建输出中根本没有这样的插件。对于 Shade，情况类似。

java

1 个回答

  1. Best Answer
    1. 使用插件版本 3+（第二个版本很旧）。
    2. 目标 - 取决于复制/解压的存储方式
    3. 在 artifactItems 配置中 - 未明确指定。

    带有解包 protobuf 依赖项的战斗配置示例：

            <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-dependency-plugin</artifactId>
            <version>3.0.0</version>
            <executions>
                <execution>
                    <id>copy-protoc</id>
                    <phase>generate-sources</phase>
                    <goals>
                        <goal>copy</goal>
                    </goals>
                    <configuration>
                        <artifactItems>
                            <artifactItem>
                                <groupId>com.google.protobuf</groupId>
                                <artifactId>protoc</artifactId>
                                <version>${protobuf.version}</version>
                                <classifier>${os.detected.classifier}</classifier>
                                <type>exe</type>
                                <overWrite>true</overWrite>
                                <outputDirectory>${project.build.directory}</outputDirectory>
                            </artifactItem>
                        </artifactItems>
                    </configuration>
                </execution>
                <execution>
                    <id>copy-google-libraries-protobuf</id>
                    <phase>generate-sources</phase>
                    <goals>
                        <goal>unpack</goal>
                    </goals>
                    <configuration>
                        <artifactItems>
                            <artifactItem>
                                <groupId>com.google.protobuf</groupId>
                                <artifactId>protobuf-java</artifactId>
                                <version>${protobuf.version}</version>
                                <type>jar</type>
                                <overWrite>false</overWrite>
                                <outputDirectory>${google.external.proto.libs}</outputDirectory>
                                <includes>google/protobuf/*.proto</includes>
                            </artifactItem>
                        </artifactItems>
                    </configuration>
                </execution>
            </executions>
        </plugin>

    如果您需要构建一个带有依赖项的 jar-nickname，那么我建议您使用 maven-shade-plugin

            <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-shade-plugin</artifactId>
            <version>2.4.3</version>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                        <goal>shade</goal>
                    </goals>
                    <configuration>
                        <finalName>${project.artifactId}</finalName>
                        <outputDirectory>${project.build.directory}</outputDirectory>
                        <filters>
                            <filter>
                                <artifact>*:*</artifact>
                                <excludes>
                                    <exclude>META-INF/*.SF</exclude>
                                    <exclude>META-INF/*.DSA</exclude>
                                    <exclude>META-INF/*.RSA</exclude>
                                </excludes>
                            </filter>
                        </filters>
                        <transformers>
                            <transformer
                                    implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                <mainClass>Main</mainClass>
                            </transformer>
                        </transformers>
                        <shadedArtifactAttached>true</shadedArtifactAttached>
                        <shadedClassifierName>executable</shadedClassifierName>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    • 1

相关问题