guava 技巧

1、Ordering排序

List<Integer> nums = new ArrayList<Integer>();//1,2,3,4,5,6 
Ordering<Object> ordering = new Ordering<>(){
  public int compare(Object o1,Object o2){
    return -1;  
  }
} 

ordering.sortedCopy(nums);
6,5,4,3,2,1

List<Integer> nums = new ArrayList<Integer>();//1,2,3,4,5,6 
Ordering<Object> ordering = new Ordering<>(){
  public int compare(Object o1,Object o2){
    return 1;  
  }
} 

ordering.sortedCopy(nums);
1,2,3,4,5,6