title: java StringBuffer and String Comparision
body: <p>Why String.equls() returns true but Stringbuilder.equals() returns false?</p>
  
  <pre><code>    StringBuffer sb1 = new StringBuffer("Amit");
      StringBuffer sb2= new StringBuffer("Amit");
      String ss1 = "Amit";
      String ss2 = "Amit";
  
  System.out.println(sb1.equals(sb2)); //returns false
  System.out.println(ss1.equals(ss2)); //returns true
  </code></pre>
  
  <p>Thx</p>