mvn-打包依赖-copy-dependency

---

slug: /mvn-copy-dependency title: mvn 打包依赖 tags: [mvn, java]

date: "2023-07-28"

mvn 打包依赖

copy-dependencies 只打包了第一层依赖

执行子模块打包后 mvn -U clean package -pl demo-task -am -DskipTests=true, lib文件里总是只包含第一层pom文件的依赖, 并没有包含所有完整的依赖, 导致程序部署运行后出现 ClassNotFound 的错误, 但编译的时候却一切正常. 后来才发现原来复制依赖jar包的时候有特殊配置.

maven-dependency-plugin插件里, copy-dependencies可以用来复制打包时候的依赖, 不过有不少特殊参数.

如果设置<excludeTransitive>false</excludeTransitive>参数如果配置为true,那么打包依赖的时候只会复制pom里的第一层依赖, 并不会复制关联的第二层依赖. 第二层依赖也叫做transitive dependencies.

• copy-dependencies

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>3.0.1</version>
                <executions>
                    <execution>
                        <id>copy-dependencies</id>
                        <phase>prepare-package</phase>
                        <goals>
                            <goal>copy-dependencies</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${project.build.directory}/lib</outputDirectory>
                            <overWriteReleases>false</overWriteReleases>
                            <overWriteSnapshots>false</overWriteSnapshots>
                            <overWriteIfNewer>true</overWriteIfNewer>
                            <excludeTransitive>false</excludeTransitive><!-- true 则不加载 继承jar -->
                        </configuration>
                    </execution>
                </executions>
            </plugin>

• 可以参考的完整打包的pom文件build依赖配置

    <build>
        <finalName>demo-task</finalName>
        <plugins>
            <!-- 编译：使用 maven-compiler-plugin 插件, 支持设定JDK版本 -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                    <showWarnings>true</showWarnings>
                    <encoding>UTF-8</encoding>
                    <skip>true</skip>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>3.0.1</version>
                <executions>
                    <execution>
                        <id>copy-dependencies</id>
                        <phase>prepare-package</phase>
                        <goals>
                            <goal>copy-dependencies</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${project.build.directory}/lib</outputDirectory>
                            <overWriteReleases>false</overWriteReleases>
                            <overWriteSnapshots>false</overWriteSnapshots>
                            <overWriteIfNewer>true</overWriteIfNewer>
                            <excludeTransitive>false</excludeTransitive><!-- true 则不加载 继承jar -->
                        </configuration>
                    </execution>
                </executions>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <configuration>
                    <archive>
                        <manifest>
                            <!-- Jar file entry point -->
                            <mainClass>com.demo.Runner</mainClass>
                            <addClasspath>true</addClasspath>
                            <classpathPrefix>lib/</classpathPrefix>
                        </manifest>
                    </archive>
                </configuration>
            </plugin>

        </plugins>
    </build>

参考

copy dependencies transitive and not transitive

https://stackoverflow.com/questions/11973889/copy-dependencies-transitive-and-not-transitive