Collections.sort Comparator.comparing 冒泡排序 效率对比

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public static void main(String[] args) {             Long t = System.currentTimeMillis();             Random random = new Random();             List<Apple> list = new ArrayList<Apple>();             for (int j = 0; j < 1000000; j++) {                 Apple a = new Apple("Apple"+1,random.nextInt(1000000));                 list.add(a);             }             Long t2 = System.currentTimeMillis();             System.out.println(t2-t);             //以下四种排序方式，任意打开一个 //          list.sort(java.util.Comparator.comparing(Apple::getWeight));                           list.sort((Apple a1, Apple a2)                     -> a1.getWeight()-a2.getWeight()                     );               //          Collections.sort(list, new Comparator<Apple>() { //              public int compare(Apple o1, Apple o2) { //                  return o2.getWeight()-o1.getWeight(); //              } //          });               //          for(int j = 0; j < list.size(); j++){ //              for(int m = j+1; m < list.size(); m++){ //                  Apple a2 = list.get(j); //                  if(a2.getWeight()>list.get(m).getWeight()){ //                      Apple am = list.get(m); //                      am.setWeight(a2.getWeight()); //                      a2.setWeight(am.getWeight()); //                  } //              } //          }                           for (int j = 0; j < 1000000; j++) {                 Apple a = list.get(j);                 //打印验证是否排序成功开关                 //System.out.println(a.getWeight());             }             Long t3 = System.currentTimeMillis();             System.out.println(t3-t2);                                               } <br>结论：不管数据量的多少，用Collections.sort，远优于另外两个，数据量少（万以下，没细测）用冒泡优于Comparator.comparing，数据量最大，冒泡越耗时，综合结论，sort 优于 comparing 优于 冒泡