title: Java DecimalFormat creates error when enforcing exponent sign
body: <p>In Java, I am trying to get DecimalFormat to enforce the sign on an exponent sign. When it is positive I need a plus sign to appear. From what I have read this seems like a no brainer, but for myself it always throws up an error. I appreciate that there may be other methods to achieve my goal, but I would like to understand why in this specific method the error is occurring.</p>
  
  <pre><code>Double result = 123.456;
  String sresult;
  
  //This works
  NumberFormat formatter = new DecimalFormat("0.00000E00");
          sresult = formatter.format(result); 
          System.out.println(sresult);        //1.23456E02
  
  //This doesn't work
  formatter = new DecimalFormat("0.00000E+00"); //Want to enforce the sign to appear
          sresult = formatter.format(result); 
          System.out.println(sresult);        //Expected 1.23456E+02 but error occurs
  </code></pre>
  
  <p>The error which is thrown up:</p>
  
  <pre>
  Exception in thread "main" java.lang.IllegalArgumentException:
  Malformed exponential pattern "0.00000E+00"
      at java.text.DecimalFormat.applyPattern(Unknown Source)
      at java.text.DecimalFormat.(Unknown Source)
      at deccheck.main(deccheck.java:13)
  </pre>
  
  <p>I appreciate any insight.
  Thanks,
  Mark</p>