Eclipse + maven: error compilation suddenly

Sometimes, you can see this error in eclipse.

[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] Unable to locate the Javac Compiler in:
  C:\Program Files (x86)\Java\jre7\..\lib\tools.jar
Please ensure you are using JDK 1.4 or above and
not a JRE (the com.sun.tools.javac.Main class is required).
In most cases you can change the location of your Java
installation by setting the JAVA_HOME environment variable.
[INFO] 1 error

This error happen when you compile eclipse and maven with jre. You must change to JDK compile in Eclise.