1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
| class Info {
final String key;
final String value;
Info(String key, String value) {
this.key = key;
this.value = value;
}
public String getKey() {
return key;
}
public String getValue() {
return value;
}
@Override
public String toString() {
return "Info{" +
"key='" + key + '\'' +
", value='" + value + '\'' +
'}';
}
}
List<Info> infos = new ArrayList<>();
infos.add(new Info("A", "B"));
infos.add(new Info("C", "D"));
Map<String, String> mp = infos.stream().collect(Collectors.toMap(Info::getKey, Info::getValue));
System.out.println(mp);
Map<Info, Map<String, String>> data = new HashMap<>();
data.put(new Info("A", "A"), new HashMap<>());
data.put(new Info("A", "B"), new HashMap<>());
data.put(new Info("A", "C"), new HashMap<>());
data.put(new Info("B", "A"), new HashMap<>());
data.put(new Info("B", "B"), new HashMap<>());
data.put(new Info("B", "C"), new HashMap<>());
Map<String, Map<Info, Map<String, String>>> rd = data.entrySet()
.stream()
.collect(Collectors.groupingBy(kv -> kv.getKey().getKey(),
Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue)));
System.out.println(rd);
{A=B, C=D}
{A={Info{key='A', value='B'}={}, Info{key='A', value='A'}={}, Info{key='A', value='C'}={}}, B={Info{key='B', value='A'}={}, Info{key='B', value='B'}={}, Info{key='B', value='C'}={}}}
|
