java 8 Lambda 表达式

java 8 以前写法：
Collections.sort(list, new Comparator<CompeteCollectorResponse>() {
     @Override
     public int compare(CompeteCollectorResponse o1, CompeteCollectorResponse o2) {
       return o1.getOrder()-o2.getOrder();
     }
    });

java 8写法：
Collections.sort(list, (CompeteCollectorResponse o1, CompeteCollectorResponse o2) -> {
    	return o1.getOrder().compareTo(o2.getOrder());
    });