title: Make an existing code in Java parallel/multithread
body: <p>I have a very simple crawler. I want to make my current code run in a few threads. Could you provide me a little tutorial or article to help me achive this test?</p>
  
  <p>I'm originally a .Net developer and in .Net I have no problem whatsoever running codes in multithread but unfortunately I don't know anything about threads in Java.</p>
  
  <p>My crawler is a command-line software so don't worry about GUI.</p>
  
  <p>Thank you in advance.</p>