DecimalFormat percent = new DecimalFormat("0.00%");
completed_num = (double) involvedTask_finished/userInvolvedTask_sum;completed_rate = percent.format(completed_num);
java 百分比显示
原文：http://www.cnblogs.com/samwang88/p/e0c253ce3655a5a0b7c1c6c6e459ef1d.html
