How to convert Timezone into specified formate?

Actually my java code like this…..
Ex:
SimpleDateFormat sourceFormat = new SimpleDateFormat(“z”);
SimpleDateFormat gmtFormat = new SimpleDateFormat(“‘GMT(‘Z’)'”);
date1 = gmtFormat.format(sourceFormat.parse(“IST”));

O/p:GMT(+0530) for example we are passing “PST” it will show GMT(-0800) but my example will show always GMT(+0530)….