ArrayList存放HashMap排序方法

Index.java

package com.test.coll;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Random;

public class Index {
    public static void main(String[] args) {
        System.out.println("---------排序前---------");
        ArrayList<HashMap<String, String>> al = Index.getRondomData();
        for (HashMap<String, String> hm : al) {
            System.out.println(hm.get("key") + ":" + hm.get("value"));
        }
        System.out.println("---------排序后---------");
        Collections.sort(al, new MySort(false, true, "key"));
        for (HashMap<String, String> hm : al) {
            System.out.println(hm.get("key") + ":" + hm.get("value"));
        }
    }

    public static ArrayList<HashMap<String, String>> getRondomData() {
        ArrayList<HashMap<String, String>> al = new ArrayList<HashMap<String, String>>();
        for (int i = 0; i < 10; i++) {
            HashMap<String, String> hm = new HashMap<String, String>();
            hm.put("key", (new Random()).nextInt(100) + "");
            hm.put("value", (new Random()).nextInt(100) + "");
            al.add(hm);
        }
        return al;
    }
}
package com.test.coll;

import