maven的conf\setting.xml文件中找到jdk注释的地方，打开修改即可，如下

    <profile>
      <id>jdk-1.7</id>

      <activation>
        <jdk>1.7</jdk>
      </activation>

      <!--<repositories>
        <repository>
          <id>jdk17</id>
          <name>Repository for JDK 1.7 builds</name>
          <url>http://www.myhost.com/maven/jdk17</url>
          <layout>default</layout>
          <snapshotPolicy>always</snapshotPolicy>
        </repository>
      </repositories>-->
	  <properties>
		<maven.compiler.source>1.7</maven.compiler.source>
		<maven.compiler.target>1.7</maven.compiler.target>
		<maven.compiler.compilerVersion>1.7</maven.compiler.compilerVersion>
	  </properties>
    </profile>