title: set class path in linux and run the jar file making executable
body: <p>I am trying to run the jar file  on linux created from windows using jdk7 . 
  I am using the following command to run the</p>
  
  <pre><code>  java -jar jarfile.jar
  </code></pre>
  
  <p>its running the jar and throwing the exception as un recognised class format version. because linux is showing the java version as 1.4.2 while i have extracted the jdk1.7 in the root directory but it is still taking the java version as 1.4.2 . what i have to do to run the jar file created using jdk1.7 . I have extracted the java (jdk1.7) on linux in root directory.</p>