title: Why I do not need to set CLASSPATH and JAVA_HOME in Mac OS X?
body: <p>I am using jdk 1.7, after Installation I did not set JAVA_HOME or CLASSPATH environment variable, and I use it to compile a servlet class and everything worked fine.</p>
  
  <p>So I want to known, why I am not supposed to set these Environment variables ? Can JDK auto resolve CLASSPATH ?</p>