map数据按照list排序

简介（Introduction）：

背景
需要对字段进行排序,但是,一个字段的结果存在一个map中,一个存在list中,需要让map的数组,按照list的顺序进行排序

结构图
list顺序

 1 [
 2     {
 3         "fieldKey":"关键字",
 4         "alias":"ID",
 5         "owner":"mysql",
 6         "field":"ID",
 7         "fieldNumber":1
 8     },
 9     {
10         "fieldKey":"名称",
11         "alias":"CHNAME",
12         "owner":"mysql",
13         "field":"NAME",
14         "fieldNumber":2
15     },
16     {
17         "fieldKey":"是否删除",
18         "alias":"DELETED",
19         "owner":"mysql",
20         "field":"ISDELETED",
21         "fieldNumber":3
22     },
23     {
24         "fieldKey":"序号",
25         "alias":"ORDERNO",
26         "owner":"mysql",
27         "field":"ORDERNO",
28         "fieldNumber":4
29     }
30 ]

View Code

map顺序

 1 {
 2     "ORDERNO":{
 3         "fieldKey":"序号",
 4         "alias":"ORDERNO",
 5         "owner":"mysql",
 6         "field":"ORDERNO",
 7         "fieldNumber":4
 8     },
 9     "NAME":{
10         "fieldKey":"名称",
11         "alias":"CHNAME",
12         "owner":"mysql",
13         "field":"NAME",
14         "fieldNumber":2
15     },
16     "ISDELETED":{
17         "fieldKey":"是否删除",
18         "alias":"DELETED",
19         "owner":"mysql",
20         "field":"ISDELETED",
21         "fieldNumber":3
22     },
23     "ID":{
24         "fieldKey":"关键字",
25         "alias":"ID",
26         "owner":"mysql",
27         "field":"ID",
28         "fieldNumber":1
29     }
30 }

View Code

核心
快速上手（Getting Started）

模型

list模型:

 1 /**
 2      * 生成资源数组
 3      *
 4      * @return 结果集
 5      */
 6     private static List<FieldDemo> getListSource() {
 7         List<FieldDemo> fieldDemos = new ArrayList<>();
 8         FieldDemo fieldDemo = new FieldDemo();
 9         fieldDemo.setField("ID");
10         fieldDemo.setAlias("ID");
11         fieldDemo.setFieldKey("关键字");
12         fieldDemo.setOwner("mysql");
13         fieldDemo.setFieldNumber(1);
14 
15         FieldDemo fieldDemo2 = new FieldDemo();
16         fieldDemo2.setField("NAME");
17         fieldDemo2.setAlias("CHNAME");
18         fieldDemo2.setFieldKey("名称");
19         fieldDemo2.setOwner("mysql");
20         fieldDemo2.setFieldNumber(2);
21 
22         FieldDemo fieldDemo3 = new FieldDemo();
23         fieldDemo3.setField("ISDELETED");
24         fieldDemo3.setAlias("DELETED");
25         fieldDemo3.setFieldKey("是否删除");
26         fieldDemo3.setOwner("mysql");
27         fieldDemo3.setFieldNumber(3);
28 
29         FieldDemo fieldDemo4 = new FieldDemo();
30         fieldDemo4.setField("ORDERNO");
31         fieldDemo4.setAlias("ORDERNO");
32         fieldDemo4.setFieldKey("序号");
33         fieldDemo4.setOwner("mysql");
34         fieldDemo4.setFieldNumber(4);
35 
36         fieldDemos.add(fieldDemo);
37         fieldDemos.add(fieldDemo2);
38         fieldDemos.add(fieldDemo3);
39         fieldDemos.add(fieldDemo4);
40 
41         return fieldDemos;
42     }

View Code

map模型:

 1 /**
 2      * 生成map
 3      *
 4      * @return map结果集
 5      */
 6     private static Map<FieldDemo, FieldDemo> getMapSource() {
 7         Map<FieldDemo, FieldDemo> map = new HashMap<>();
 8         List<FieldDemo> listSource = getListSource();
 9         List<FieldDemo> listSource2 = getListSource2();
10         for (FieldDemo fieldDemo : listSource) {
11             for (FieldDemo demo : listSource2) {
12                 if (fieldDemo.getField().equalsIgnoreCase(demo.getField())) {
13                     map.put(fieldDemo, demo);
14                 }
15             }
16         }
17         return map;
18     }
19 
20 
21     private static List<FieldDemo> getListSource2() {
22         List<FieldDemo> fieldDemos = new ArrayList<>();
23         FieldDemo fieldDemo = new FieldDemo();
24         fieldDemo.setField("ID");
25         fieldDemo.setAlias("ID");
26         fieldDemo.setFieldKey("关键字");
27         fieldDemo.setOwner("mysql");
28         fieldDemo.setFieldNumber(1);
29 
30 
31         FieldDemo fieldDemo2 = new FieldDemo();
32         fieldDemo2.setField("NAME");
33         fieldDemo2.setAlias("CHNAME");
34         fieldDemo2.setFieldKey("名称");
35         fieldDemo2.setOwner("mysql");
36         fieldDemo2.setFieldNumber(2);
37 
38 
39         FieldDemo fieldDemo3 = new FieldDemo();
40         fieldDemo3.setField("ISDELETED");
41         fieldDemo3.setAlias("DELETED");
42         fieldDemo3.setFieldKey("是否删除");
43         fieldDemo3.setOwner("mysql");
44         fieldDemo3.setFieldNumber(3);
45 
46 
47         FieldDemo fieldDemo4 = new FieldDemo();
48         fieldDemo4.setField("ORDERNO");
49         fieldDemo4.setAlias("ORDERNO");
50         fieldDemo4.setFieldKey("序号");
51         fieldDemo4.setOwner("mysql");
52         fieldDemo4.setFieldNumber(4);
53 
54 
55         fieldDemos.add(fieldDemo4);
56         fieldDemos.add(fieldDemo3);
57         fieldDemos.add(fieldDemo);
58         fieldDemos.add(fieldDemo2);
59         return fieldDemos;
60     }

View Code

业务

核心处理

 1  /**
 2      * 让复杂map按照list的顺序排序
 3      *
 4      * @param list
 5      * @param map
 6      * @param newMap
 7      */
 8     public static void sortMapFromList(List<FieldDemo> list, Map<FieldDemo, FieldDemo> map, Map<FieldDemo, FieldDemo> newMap) {
 9 
10         Map<FieldDemo, Integer> middleMap = new HashMap<>(16);
11 
12         for (FieldDemo fieldDemo : list) {
13             for (Map.Entry<FieldDemo, FieldDemo> fieldDemoFieldDemoEntry : map.entrySet()) {
14                 String field = fieldDemoFieldDemoEntry.getKey().getField();
15 
16                 if (field.equalsIgnoreCase(fieldDemo.getField())) {
17                     // 生成中间存储map,存入数据和对应的序号
18                     middleMap.put(fieldDemoFieldDemoEntry.getKey(), fieldDemo.getFieldNumber());
19                 }
20             }
21         }
22 
23         // 生成的结果集加入到list中
24         List<Map.Entry<FieldDemo, Integer>> entryList = new ArrayList(middleMap.entrySet());
25 
26         // 根据value 进行排序
27         Collections.sort(entryList, new Comparator<Map.Entry<FieldDemo, Integer>>() {
28             @Override
29             public int compare(Map.Entry<FieldDemo, Integer> o1, Map.Entry<FieldDemo, Integer> o2) {
30                 return o1.getValue().compareTo(o2.getValue());
31             }
32         });
33 
34         System.out.println("entryList:" + new Gson().toJson(entryList));
35 
36         for (Map.Entry<FieldDemo, Integer> fieldDemoFieldDemoEntry : entryList) {
37 
38             for (Map.Entry<FieldDemo, FieldDemo> demoFieldDemoEntry : map.entrySet()) {
39 
40                 String field = demoFieldDemoEntry.getKey().getField();
41 
42                 if (field.equalsIgnoreCase(fieldDemoFieldDemoEntry.getKey().getField())) {
43 
44                     System.out.println("fieldNumber:" + new Gson().toJson(fieldDemoFieldDemoEntry.getValue()));
45                     System.out.println("fieldDemoFieldDemoEntry:" + new Gson().toJson(fieldDemoFieldDemoEntry.getKey()));
46                     System.out.println("demoFieldDemoEntry:" + new Gson().toJson(demoFieldDemoEntry.getValue()));
47 
48                     newMap.put(fieldDemoFieldDemoEntry.getKey(), demoFieldDemoEntry.getValue());
49                 }
50             }
51         }
52     }

View Code

测试

 1 public static void main(String[] args) {
 2 
 3         FieldDemo fieldDemo = new FieldDemo();
 4 
 5         System.out.println("fieldDemo顺序:" + new Gson().toJson(fieldDemo));
 6 
 7         // 让listSource2跟listSource顺序一致
 8         Map<FieldDemo, FieldDemo> mapSource = getMapSource();
 9 
10         System.out.println("map顺序:" + new Gson().toJson(mapSource));
11 
12         List<FieldDemo> listSource = getListSource();
13 
14         System.out.println("list顺序:" + new Gson().toJson(listSource));
15 
16         // mapSource 跟 listSource顺序一致,去除不是listSource理的字段
17         Map<FieldDemo, FieldDemo> newMap = new HashMap<>();
18 
19         sortMapFromList(listSource, mapSource, newMap);
20 
21         System.out.println("排序后:" + newMap);
22     }

View Code

待开发中

环境设置 （Prerequisite）：
- 环境
  JDK1.8
- 配置
  IDEA 2019
- 存在问题
  暂无
进阶篇 （Advanced）：

研究中 ......

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原文地址：https://www.cnblogs.com/liuyangfirst/p/13341875.html