title: Java Interfaces Methodology: Should every class implement an interface?
body: <p>I've been programming in Java for a few courses in the University and I have the following question:</p>
  
  <blockquote>
    <p>Is it methodologically accepted that every class should implement an interface? Is it considered bad practice not to do so? Can you describe a situation where it's not a good idea to use interfaces?</p>
  </blockquote>
  
  <p><strong>Edit:</strong> Personally, I like the notion of using Interfaces for everything as a methodology and habit, even if it's not clearly beneficial. Eclipse automatically created a class file with all the methods, so it doesn't waste any time anyway.</p>