maven：新建的maven工程需要添加一下插件

//下面的代码是改变maven的默认使用Java版本，本机是jdk1.7所以用1.7
<plugins>
  	<plugin>
  		<groupId>org.apache.maven.plugins</groupId>
  		<artifactId>maven-compiler-plugin</artifactId>
  		<configuration>
  			<source>1.7</source>
  			<target>1.7</target>
  		</configuration>
  	</plugin>
  	//该插件是用来将test的main方法加进manifest，这样可以直接运行jar: java -jar *.jar
  	<plugin>
  	<groupId>org.apache.maven.plugins</groupId>
  		<artifactId>maven-shade-plugin</artifactId>
  		<version>1.2.1</version>
  		<executions>
  			<execution>
  				<phase>package</phase>
  				<goals>
  					<goal>shade</goal>
  				</goals>
  				<configuration>
  					<transformers>
  						<transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
  						<mainClass>com.juvenxu.mvnbook.helloworld.HelloWorld</mainClass>

  						</transformer>>
  					</transformers>
  				</configuration>
  			</execution>
  		</executions>
  	</plugin>
  </plugins>