如何转换下面的Json到Java Pojo类

Question

Json下面的Kidly检查。我想把它转换成POJO类。

我试过使用以下级别的

@Data
public class Root {
@JsonProperty("0")      // Dont want to pass like this. it should be single list and index is the key of that array
public List<Request> list;
@JsonProperty("1")
public List<Request> list1;
@JsonProperty("2")
public List<Request> list2;
@Data
private class Request {
int id;
String title;
int level;
List<Request> children;
@JsonProperty("parent_id")
int parentId;
}
}

{
"0": [
{
"id": 12123,
"title": "sfsdf",
"level": 0,
"children": [

],
"parent_id": null
}
],
"1": [
{
"id": 213,
"title": "d",
"level": 1,
"children": [

],
"parent_id": 1212312
},
{
"id": 3232,
"title": "dfsdf",
"level": 1,
"children": [

],
"parent_id": 42
},
{
"id": 234,
"title": "tder",
"level": 1,
"children": [

],
"parent_id": 122
}
],
"2": [
{
"id": 452,
"title": "Blll",
"level": 2,
"children": [

],
"parent_id": 322
},
{
"id": 123,
"title": "trrr",
"level": 11,
"children": [

],
"parent_id": 1221
},
{
"id": 33,
"title": "sdfw",
"level": 2123,
"children": [

],
"parent_id": 10
}
]
}

Answer 1

使用@JsonAnySetter。

示例，为了简单起见，使用public字段：

class Root {
@JsonAnySetter
public Map<String, List<Request>> lists = new LinkedHashMap<>();
}
class Request {
public int id;
public String title;
public int level;
public List<Request> children;
@JsonProperty("parent_id")
public Integer parentId; // 'Integer', not 'int', since it can be null
}

测试

ObjectMapper mapper = new ObjectMapper();
Root root = mapper.readValue(new File("test.json"), Root.class);
for (Entry<String, List<Request>> entry : root.lists.entrySet()) {
System.out.println(entry.getKey() + ":");
for (Request request : entry.getValue()) {
System.out.println("  id=" + request.id +
", title=" + request.title +
", level=" + request.level +
", children=" + request.children +
", parentId=" + request.parentId);
}
}

输出

0:
id=12123, title=sfsdf, level=0, children=[], parentId=null
1:
id=213, title=d, level=1, children=[], parentId=1212312
id=3232, title=dfsdf, level=1, children=[], parentId=42
id=234, title=tder, level=1, children=[], parentId=122
2:
id=452, title=Blll, level=2, children=[], parentId=322
id=123, title=trrr, level=11, children=[], parentId=1221
id=33, title=sdfw, level=2123, children=[], parentId=10

Answer 2

只需删除第二个和第三个列表。只保留单个列表，并让它保留其名称，如list或requests。然后添加到该列表中。

Root root = new Root(); // whatever
root.getRequests().add(myFirstRequest); // index 0 in the array
root.getRequests().add(mySecondRequest); // index 1 in the array
root.getRequests().add(myThirdRequest); // index 2 in the array
String json = // however you were making json out of Root before

Answer 3

通过在控制器请求体中传递Map<String, List<Request>> lists。我的问题已经解决了。我得到了我所期望的JSON。