MAP 不能存动态DATE类

Date date = sdfAll.parse(datetime);

for (int i = 0; i < jxWidth/40+1; i++) {

date.setTime(date.getTime()-300000);

System.out.println(jxWidth+jxX-i*40);

System.out.println(date);

mapXInfo.put(jxWidth+jxX-i*40, date);

返回的VALUE 都是保存循环的最后一个