maven插件是用来完成构建任务的。用户可以通过两种方式调用Maven插件。
第一种方式是将插件与生命周期绑定，如命令mvn compile就实现了maven-compiler-plugin的调用目标。
第二种方式是直接在命令行指定要执行的插件，如mvn archetype:generate 就表示调用maven-archetype-plugin。

1.maven-assembly-plugin

用于导出jar包或war包。插件官网：http://maven.apache.org/plugins/maven-assembly-plugin/

具体打包哪些文件是高度可控的，在assembly.xml中指定。

<!--一个assembly.xml例子-->
<assembly
        xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0 http://maven.apache.org/xsd/assembly-1.1.0.xsd">
    <formats>
        <format>jar</format>
    </formats>
    <id>with-dependencies</id>
    <includeBaseDirectory>false</includeBaseDirectory>
    <dependencySets>
        <dependencySet>
            <excludes>
                <exclude>org.apache.storm:storm-core</exclude>
            </excludes>
            <outputDirectory>/</outputDirectory>
            <useProjectArtifact>true</useProjectArtifact>
            <unpack>true</unpack>
            <scope>runtime</scope>
        </dependencySet>
    </dependencySets>
</assembly>

2.maven-source-plugin

打包时用的，附带源代码。pom写法见下：

 <plugin>
       <artifactId>maven-source-plugin</artifactId>
       <version>2.1</version>
       <configuration>
           <attach>true</attach>
       </configuration>
       <executions>
           <execution>
               <phase>compile</phase>
               <goals>
                   <goal>jar</goal>
               </goals>
           </execution>
       </executions>
 </plugin> 

3.maven-dependency-pligin

打包时用。用于把项目的依赖单独放到 jar外 的一个目录中。

<plugin>
	<artifactId>maven-dependency-plugin</artifactId>
	<version>2.10</version>
	<executions>
		<execution>
			<id>copy-dependencies</id>
			<phase>package</phase>
			<goals>
				<goal>copy-dependencies</goal>
			</goals>
			 <configuration>
			 </configuration>
		</execution>
	</executions>
</plugin>

4.maven-enforcer-plugin

当一个旧的库被很多库间接依赖，挨个使用<excluds>不简洁时，可使用这个插件强制排除过时的依赖。有些框架升级时artifactid都会变，比如spring升级为spring-core。

<!-- 排除包 -->
<plugin>
	<groupId>org.apache.maven.plugins</groupId>
	<artifactId>maven-enforcer-plugin</artifactId>
	<version>1.1</version>
	<executions>
		<execution>
			<id>enforce-denpendency</id>
			<phase>compile</phase>
			<goals>
				<goal>enforce</goal>
			</goals>
			<configuration>
				<rules>
					<bannedDependencies>
						<!-- groupId[:artifactId][:version][:type][:scope] -->
						<excludes>
							<!--<exclude>ch.qos.logback</exclude> -->
							<exclude>org.slf4j:log4j-over-slf4j</exclude>
							<exclude>org.springframework:spring</exclude>
						</excludes>
					</bannedDependencies>
				</rules>
				<fail>true</fail>
			</configuration>
		</execution>
	</executions>
</plugin>