maven set Jdk version to compile

pom.xml

      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.3</version>
        <configuration>
          <source>1.7</source>
          <target>1.7</target>
          <!--<compilerArgs>-->
            <!--<arg>-Xlint:unchecked</arg>-->
            <!--<arg>-Xlint:deprecation </arg>-->
          <!--</compilerArgs>-->
          <encoding>UTF-8</encoding>
        </configuration>
      </plugin>