title: Why do we need Maven or Ant, if we already have Eclipse?
body: <p>I think this question is an extension of <a href="https://stackoverflow.com/questions/7884809/compare-to-the-ide-for-java-do-we-still-need-ant">Compare to the IDE for Java,do we still need Ant?</a></p>
  
  <p>There are answers for the question above, but I wish to know a concrete example of using Maven or Ant over just Eclipse. </p>
  
  <p>When I develop in Eclipse, Eclipse does everything for me and I just need to click the run button. And also, Eclipse can let you export your code to a runnable jar or even .exe for windows.</p>
  
  <p>So I really don't know why I need Maven or Ant.</p>
  
  <p>And also if I do need, <strong>which one should I choose, Maven or Ant?</strong></p>