说明

本文是对maven-dependency-plugin常用配置的介绍，更详细的学习请参照官网文档地址： Apache Maven Dependency Plugin
maven-dependency-plugin作用：依赖插件提供了操作构件的能力。它可以从本地或远程存储库复制或解压构件到指定位置。它有很多可用的goal，但是我们最常用到的是 dependency:copy，dependency:copy-dependencies及dependency:unpack，dependency:unpack-dependencies这四个

1. 使用演示

此处演示常用的dependency:copy、dependency:copy-dependencies和dependency:unpack

1.1 插件声明

<build>
	<plugin>
		<groupId>org.apache.maven.plugins</groupId>
		<artifactId>maven-dependency-plugin</artifactId>
		<version>3.6.0</version>
	</plugin>
</build>

1.2 dependency:copy

它将从存储库中解析artifact，获取在插件配置部分定义的一系列构件，并将它们复制到指定的位置。如果需要，还可以重命名它们或去除版本号。如果远程仓库存在本地仓库不存在这些构件，该目标还可以从远程仓库解析这些构件。添加phase和goal如下
com.alibaba.fastjson拷到libs目录下：

<build>  
    <plugins>  
        <plugin>  
            <groupId>org.apache.maven.plugins</groupId>  
            <artifactId>maven-dependency-plugin</artifactId>  
            <version>3.6.0</version>  
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                        <goal>copy</goal>
                    </goals>
                    <configuration>
                        <artifactItems>
                            <artifactItem>
                                <groupId>com.alibaba</groupId>
                                <artifactId>fastjson</artifactId>
                                <version>1.2.83</version>
                                <outputDirectory>${project.build.directory}/libs</outputDirectory>
                            </artifactItem>
                        </artifactItems>
                    </configuration>
                </execution>
            </executions>
        </plugin>  
    </plugins>  
</build>  

1.3 dependency:copy-dependencies

与dependency:copy类似，只不过是将项目所有的依赖copy到指定的地方

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-dependency-plugin</artifactId>
            <version>3.6.0</version>
            <executions>
                <execution>
                	<!-- 任意名字 -->
                    <id>copy-dependencies</id>
                    <phase>package</phase>
                    <goals>
                        <goal>copy-dependencies</goal>
                    </goals>
                    <configuration>
                        <outputDirectory>${project.build.directory}/lib</outputDirectory>
                        <!-- 间接依赖也拷贝 -->
						<excludeTransitive>false</excludeTransitive>
						<!-- 带上版本号 -->
						<stripVersion>false</stripVersion>
						<!--覆盖发布工件-->
                		<overWriteReleases>false</overWriteReleases>
                		<!--覆盖快照项目-->
                		<overWriteSnapshots>false</overWriteSnapshots>
                		<!--覆盖不存在或比源文件更旧的构建产物-->
                		<overWriteIfNewer>true</overWriteIfNewer>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

1.4 dependency:unpack

官方释义：类似于复制，但会解包。简单理解就是把依赖jar解包复制，我们可以利用解包效果分离出一些依赖jar已经写好的脚本

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-dependency-plugin</artifactId>
            <version>3.6.0</version>
            <executions>
                <execution>
                    <id>unpack</id>
                    <phase>package</phase>
                    <goals>
                        <goal>unpack</goal>
                    </goals>
                    <configuration>
                        <artifactItems>
                            <artifactItem>
                                <groupId>org.slf4j</groupId>
                                <artifactId>slf4j-api</artifactId>
                                <version>1.7.36</version>
                                <outputDirectory>${project.build.directory}/unpack/slf4j</outputDirectory>
                            </artifactItem>
                            <artifactItem>
                                <groupId>com.alibaba</groupId>
                                <artifactId>fastjson</artifactId>
                                <version>1.2.83</version>
                                <outputDirectory>${project.build.directory}/unpack/fastjson</outputDirectory>
                            </artifactItem>
                        </artifactItems>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>