maven-shade-plugin介绍及使用

基本功能

maven-shade-plugin提供了两大基本功能：

1. 将依赖的jar包打包到当前jar包（常规打包是不会将所依赖jar包打进来的）；
2. 对依赖的jar包进行重命名（用于类的隔离）；

Goals

maven-shade-plugin 只存在一个goal shade:shade，需要将其绑定到 phase package 上，使用框架如下：

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>3.1.1</version>
        <configuration>
          <!-- put your configurations here -->
        </configuration>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
</project>

然后在当前pom文件所在路径下，执行打包命令：

mvn clean package

示例1：将部分jar包添加或排除

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>3.1.1</version>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
            <configuration>
              <artifactSet>
                <excludes>
                  <exclude>jmock:*</exclude>
                  <exclude>*:xml-apis</exclude>
                  <exclude>org.apache.maven:lib:tests</exclude>
                  <exclude>log4j:log4j:jar:</exclude>
                </excludes>
                <includes>
                    <include>junit:junit</include>
                </includes>
              </artifactSet>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
</project>

说明：

1. jar包以groupId:artifactId[[:type]:classifier]的形式表示；
2. 1.3版本后插件支持通配符 ‘*’ and ‘?’ ；

示例2：将依赖jar包内部资源添加或排除

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>3.1.1</version>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
            <configuration>
              <filters>
                <filter>
                  <artifact>junit:junit</artifact>
                  <includes>
                    <include>junit/framework/**</include>
                    <include>org/junit/**</include>
                  </includes>
                  <excludes>
                    <exclude>org/junit/experimental/**</exclude>
                    <exclude>org/junit/runners/**</exclude>
                  </excludes>
                </filter>
                <filter>
                  <artifact>*:*</artifact>
                  <excludes>
                    <exclude>META-INF/*.SF</exclude>
                    <exclude>META-INF/*.DSA</exclude>
                    <exclude>META-INF/*.RSA</exclude>
                  </excludes>
                </filter>
              </filters>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
</project>

示例3：自动将所有不使用的类排除

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>3.1.1</version>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
            <configuration>
              <minimizeJar>true</minimizeJar>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
</project>

示例4：将依赖的类重命名并打包进来 （隔离方案）

将“org.codehaus.plexus.util”重命名为“org.shaded.plexus.util”，原始jar包中的“org.codehaus.plexus.util.xml.Xpp3Dom”和“org.codehaus.plexus.util.xml.pull”不会被重命名到目的包中；

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>3.1.1</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>

示例5：修改包的后缀名

默认会生成一个Jar包和一个以 “-shaded”为结尾的uber-jar包，可以通过配置来指定uber-jar的后缀名。

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>3.1.1</version>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
            <configuration>
              <shadedArtifactAttached>true</shadedArtifactAttached>
              <shadedClassifierName>jackofall</shadedClassifierName> <!-- Any name that makes sense -->
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
</project>

问题1：Invalid signature file digest for Manifest main attributes

原因：有些jar包生成时，会 使用jarsigner生成文件签名（完成性校验），分为两个文件存放在META-INF目录下：

1. a signature file, with a .SF extension；
2. a signature block file, with a .DSA, .RSA, or .EC extension；

解决方案：生成 uber-jar时，将这些排除掉，不再进行完成性校验，如下所示：

<configuration>
          <filters>
            <filter>
              <artifact>*:*</artifact>
              <excludes>
                <exclude>META-INF/*.SF</exclude>
                <exclude>META-INF/*.DSA</exclude>
                <exclude>META-INF/*.RSA</exclude>
              </excludes>
            </filter>
          </filters>
        </configuration>

参考：

1. https://maven.apache.org/plugins/maven-shade-plugin/examples/attached-artifact.html；
2. http://zhentao-li.blogspot.com/2012/06/maven-shade-plugin-invalid-signature.html；