list集合按元素的某一属性排序


import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * ClassName: Sort 
 * @Description: list集合按元素的某一属性排序
 * @author ljw
 * @date 2018年5月24日
 */
public class Sort {
    
    public static void main(String[] args) {
        
        List<Map<String, Integer>> list = new ArrayList<>();
        
        for (int i = 0; i < 10; i++) {
            Map<String, Integer> map = new HashMap<>();
            Integer random = (int)(Math.random() * 100);
            map.put("random", random);
            list.add(map);
        }
        
        //排序前
        System.out.println("排序前:" + list);
        
        Collections.sort(list, new Comparator<Map<String, Integer>>() {
            public int compare(Map<String, Integer> m1, Map<String, Integer> m2) {
                //降序
//                return m2.get("random").compareTo(m1.get("random"));
                //升序
                return m1.get("random").compareTo(m2.get("random"));                
            }
        });
        
        //排序后
        System.out.println("排序后:" + list);
    }
}

排序前:[{random=79}, {random=44}, {random=38}, {random=65}, {random=43}, {random=83}, {random=90}, {random=87}, {random=83}, {random=13}]
 
排序后:[{random=13}, {random=38}, {random=43}, {random=44}, {random=65}, {random=79}, {random=83}, {random=83}, {random=87}, {random=90}]


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