title: fail in "mvn clean install"?
body: <p>I am new in learning java programming!  I want to make a .jar in a maven project. After running this command <code>mvn clean install</code>, I am getting the following error message:</p>
  <blockquote>
  <p>Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile(default-compile) on project wps-demo: Compilation failure</p>
  <p>Unable to locate the Javac Compiler in:C:\Program Files\Java\jre7..\lib\tools.jar</p>
  <p>Please ensure you are using JDK 1.4 or above and not a JRE(the com.sun.tools.javac.Main class is required)</p>
  <p>In most cases you can change the location of your Java</p>
  <p>installation by setting the JAVA_HOME environment variable</p>
  </blockquote>
  <p>what can I do for clean this error!</p>