【maven插件】maven-shade-plugin

概述

该插件提供了将artifact打包到一个本地jar包的能力，包括其依赖关系以及一些参数如 shade -rename重命名依赖关系的包。

目标

shade：shade 绑定到建生命周期中的package阶段，用于创建a shaded jar。

　　mvn package

用法

1.配置

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>3.0.0</version>
        <configuration>
          <!-- put your configurations here -->
        </configuration>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
</project>

2.支持的transformer

<configuration>
    <!-- 打包带有主函数入口的jar报 -->
    <transformers>
         <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
             <mainClass>com.ultrapower.secsight.main.Runner</mainClass>
         </transformer>
    </transformers>
</configuration>

ApacheLicenseResourceTransformer    防止许可复制
ApacheNoticeResourceTransformer    Prepares merged NOTICE
AppendingTransformer    Adds content to a resource
ComponentsXmlResourceTransformer    Aggregates Plexus components.xml
DontIncludeResourceTransformer    Prevents inclusion of matching resources
IncludeResourceTransformer    Adds files from the project
ManifestResourceTransformer    设置清单MANIFEST中的条目
ServicesResourceTransformer    Merges META-INF/services resources
XmlAppendingTransformer    Adds XML content to an XML resource

用例

 1.控制本地JAR的依赖

通过exclude/include控制本地JAR的依赖：

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>3.0.0</version>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
            <configuration>
              <artifactSet>
                <excludes>
                  <exclude>classworlds:classworlds</exclude>
                  <exclude>junit:junit</exclude>
                  <exclude>jmock:*</exclude>
                  <exclude>*:xml-apis</exclude>
                  <exclude>org.apache.maven:lib:tests</exclude>
                  <exclude>log4j:log4j:jar:</exclude>
                </excludes>
              </artifactSet>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
</project>

 2.自动精简uber-jar

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>3.0.0</version>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
            <configuration>
              <minimizeJar>true</minimizeJar>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
</project>

从版本1.6开始，minimizeJar将保留在filter中标记为include的类。请注意，为artifact中的类指定include filter会隐式将该artifact中的所有其他非指定类排除。

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>3.0.0</version>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
            <configuration>
              <minimizeJar>true</minimizeJar>
              <filters>
                <filter>
                   <artifact>log4j:log4j</artifact>
                   <includes>
                       <include>**</include>
                   </includes>
                </filter>
                <filter>
                   <artifact>commons-logging:commons-logging</artifact>
                   <includes>
                       <include>**</include>
                   </includes>
                </filter>
              </filters>            
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
</project>

3.Classes重定位

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>3.0.0</version>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
            <configuration>
              <relocations>
                <relocation>
                  <pattern>org.codehaus.plexus.util</pattern>
                  <shadedPattern>org.shaded.plexus.util</shadedPattern>
                  <excludes>
                    <exclude>org.codehaus.plexus.util.xml.Xpp3Dom</exclude>
                    <exclude>org.codehaus.plexus.util.xml.pull.*</exclude>
                  </excludes>
                </relocation>
              </relocations>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
</project>

遇到错误

Failed to execute goal org.apache.maven.plugins:maven-shade-plugin:1.6:shade (default) on project justfortest: Error creating shaded jar: null: NullPointerException -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-shade-plugin:1.6:shade (default) on project justfortest: Error creating shaded jar: null

该插件不能够用于父项目POM，即<packaging>pom</packaging>