m2e Compiler J2SE-1.5 Warning Message

I got the warning message as below while developing m2e project:


"Build path specifies execution environment J2SE-1.5. There are no JREs installed in the workspace that are strictly compatible with this environment."


Simple way to solve this problem is to add JRE System library in Java build path.
Preferences->Java->Installed JREs->Add


Or go  Preferences->Java->Compiler
to change JDK Compliance to 1.6
However, this will all back to 1.5 if execute maven -update project configuration. Therefore, the best way is to modify the file "maven-compiler-plugin.pom", that is located in
C:\Documents and Settings\xxx\.m2\repository\org\apache\maven\plugins\maven-compiler-plugin\2.3.2


  <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>2.1</version>
          <configuration>
            <source>1.6</source>
            <target>1.6</target>
          </configuration>
  </plugin>

Then, the warning message should be fixed!