str.split('-').forEach(function(a,i,b){
    result += i===0?(b[2]+'-'):i===1?(((new Date(str)).toUTCString()).split(' ')[2]+'-').toUpperCase():a[0];
});

String OLD_FORMAT = "yyyy-MM-dd";
String NEW_FORMAT = "dd-MMM-yyyy";

String oldDateString = "2015-04-08";
String newDateString;

SimpleDateFormat sdf = new SimpleDateFormat(OLD_FORMAT);
Date d = sdf.parse(oldDateString);
sdf.applyPattern(NEW_FORMAT);
newDateString = sdf.format(d);

var c = new Date('2015-04-08');
locale = "en-us"
function formatDate(d)
 {
    var month = d.toLocaleString(locale, { month: "long" });
    var day = d.getDate();
    day = day + "";
    if (day.length == 1)
     {
     day = "0" + day;
      }
      return day + '-' + month +'-' + d.getFullYear();
  }

String myDateString = "2015-04-08";
String reqDateString = new SimpleDateFormat("dd-MMM-yyyy").format(myDateString);