Java的数组与集合排序问题

数组排序

  1. 先实现Comparable接口

  2. 重写compareTo函数

    public class Main implements Comparable{
    				 long sid;
    				 int dgra;
    				 int cgra;
    				 int sum;
    			public int compareTo(Object o) {
    					 Main p=(Main)o;
    					  int n= sum<p.sum?1:(sum==p.sum?0:-1);
    					  if(n==0)
    					  {
    					   n=dgra<p.dgra?1:(dgra==p.dgra?0:-1);
    					   if(n==0)
    						   n=sid>p.sid?1:-1;
    					  }
    					  return n;
    				}
    				public static void main(String[] args) {
    					Main[] stu2 = new Main[k];
    					Arrays.sort(stu1);
    				}
    			}

集合排序

  1. 先实现Comparable接口

  2. 重写compareTo函数

    1. public class Main implements Comparable<Main>{
       	 long sid;
       		 int dgra;
       		 int cgra;
       		 int sum;
       	@Override
       		public int compareTo(Main o) {
       			Main p=o;
       			  int n= sum<p.sum?1:(sum==p.sum?0:-1);
       			  if(n==0)
       			  {
       			   n=dgra<p.dgra?1:(dgra==p.dgra?0:-1);
       			   if(n==0)
       				   n=sid>p.sid?1:-1;
       			  }
       			  return n;
       		}
       		public static void main(String[] args) {
       							List<Main> stu1 = new ArrayList<Main>();
       							Collections.sort(stu1);
       						}
       	}


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