Java中List排序实业，帮忙看看呀

Java中List排序实体，帮忙看看呀
Source source = new Source();
Source source2 = new Source();
for (int i = 0; i < listScoure.size()-1; i++) {
if (listScoure.get(i) != null) {
source = (Source) listScoure.get(i);
for (int j = i; j < listScoure.size(); j++) {
if (listScoure.get(j) != null) {
source2 = (Source) listScoure.get(j)
// 高分到低分排序
if (source.getScore() < source2.getScore()) {
listScoure.set(i, source2);
listScoure.set(j, source);
}

------解决方案--------------------
晕，上面类型错了。
直接copy Integer的方法
 compareTo(Source anotherInteger)