深入List＜map＜string,object＞＞ 集合排序的方法总结

由于最近接口中有一些数据是从MySQL中查询出来的，使用Rest请求返回的数据是List<map<string,object>>类型。
原始数据返回结构：

1.需求的来源

如下返回的resourceId需要进行排序，呵呵，能排序，就是比较麻烦点，我找机会参阅资料总结一下吧。

{
    "total": 15,
    "data": [
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1",
            "resourceName": "4-OPCOM100-CPM12A"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=4#portType=263",
            "resourceName": "4-C/1331(波道4)"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=5#portType=263",
            "resourceName": "4-C/1351(波道5)"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=3#portType=263",
            "resourceName": "4-C/1311(波道3)"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=7#portType=263",
            "resourceName": "4-C/1471(波道11)"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=6#portType=263",
            "resourceName": "4-C/1371(波道6)"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=1#portType=263",
            "resourceName": "4-C/1271(波道1)"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=10#portType=263",
            "resourceName": "4-C/1531(波道14)"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=1#portType=262",
            "resourceName": "4-Pri"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=8#portType=263",
            "resourceName": "4-C/1491(波道12)"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=9#portType=263",
            "resourceName": "4-C/1511(波道13)"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=12#portType=263",
            "resourceName": "4-C/1571(波道16)"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=11#portType=263",
            "resourceName": "4-C/1551(波道15)"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=2#portType=262",
            "resourceName": "4-Sec"
        },
        {
            "leaf": "true",
            "resourceId": "/ne=100007/shelf=1/slot=4/card=1.1/port=2#portType=263",
            "resourceName": "4-C/1291(波道2)"
        }
    ]
}

看着比较蛋疼了 。

2.编写测试类

如下不太实用【String进行排序是按照字母表顺序的】，因为如下的count是整数，对整数进行排序的，要想正确排序，需要找到规律，进行特殊处理。

该代码是按照map的value排序了。

package com.raisecom.tiap.ems.basic.mgt.controller.wdm.semiactive;

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

/**
 * @author yangl-006305
 * @version V1.0
 * @date 2020-08-15 17:52
 */
public class SortListHashMap {
    public static void main(String[] args) {

        List<Map<String, Object>> listResult = new ArrayList<Map<String, Object>>();

        Map<String, Object> map1 = new LinkedHashMap<String, Object>();
        map1.put("count", 2);
        map1.put("name", "abc");
        map1.put("key", "acv");
        listResult.add(map1);

        Map<String, Object> map2 = new LinkedHashMap<String, Object>();
        map2.put("count", 3);
        map2.put("name", "bbc");
        map2.put("key", "bcv");
        listResult.add(map2);

        Map<String, Object> map3 = new LinkedHashMap<String, Object>();
        map3.put("count", 1);
        map3.put("name", "cbc");
        map3.put("key", "ccv");
        listResult.add(map3);

        Map<String, Object> map4 = new LinkedHashMap<String, Object>();
        map4.put("count", 4);
        map4.put("name", "cbc");
        map4.put("key", "ccv");
        listResult.add(map4);

        System.out.println("排序前：");
        for (Map<String, Object> map : listResult) {
            System.out.println("count:"+map.get("count")+" name:"+map.get("name")+" key:"+map.get("key"));
        }

        Collections.sort(listResult, new MapComparatorDesc());

        System.out.println("降序：");
        for (Map<String, Object> map : listResult) {
            System.out.println("count:"+map.get("count")+" name:"+map.get("name")+" key:"+map.get("key"));
        }

        Collections.sort(listResult, new MapComparatorAsc());

        System.out.println("升序：");
        for (Map<String, Object> map : listResult) {
            System.out.println("count:"+map.get("count")+" name:"+map.get("name")+" key:"+map.get("key"));
        }
    }
    static class MapComparatorDesc implements Comparator<Map<String, Object>> {
        @Override
        public int compare(Map<String, Object> m1, Map<String, Object> m2) {
            Integer v1 = Integer.valueOf(m1.get("count").toString());
            Integer v2 = Integer.valueOf(m2.get("count").toString());
            if (v2 != null) {
                return v2.compareTo(v1);
            }
            return 0;
        }

    }
    static class MapComparatorAsc implements Comparator<Map<String, Object>> {
        @Override
        public int compare(Map<String, Object> m1, Map<String, Object> m2) {
            Integer v1 = Integer.valueOf(m1.get("count").toString());
            Integer v2 = Integer.valueOf(m2.get("count").toString());
            if(v1 != null){
                return v1.compareTo(v2);
            }
            return 0;
        }

    }
}