Question

我对服务进行了休息调用并将响应存储在JSONObject中。但是，我试图将其转换为类对象并获得错误。这是我的代码：

RestOperations operations = /*initalize*/;
String body = /*build request body*/;
String resourceResponse = operations.postForObject(/* url */, body, String.class);
JSONObject jsonResponse = new JSONObject(resourceResponse);
UserIdentifier userIdentifier = (UserIdentifier) jsonResponse.get("userIdentifier");

以下是响应的内容：

{
  "userIdentifier": {
    "uid": "ee63a52cda7bf411dd8603ac196951aa77",
    "code": "63a5297e7bf411dd8603ac196951aa77",
    "retailId": "860658787",
    "pointOfEntry": "RETAIL"
  },
  "resultCode": true
}

以下是UserIdentifier类的内容：

public class UserIdentifier {
    private String uid;
    private String code;
    private String retailId;

    public UserIdentifier() {

    }

    public UserIdentifier(String uid, String code, String retailId) {
        this.uid = uid;
        this.code = code;
        this.retailId = retailId;
    }

    public String getuid() {
        return uid;
    }

    public void setuid(String uid) {
        this.uid = uid;
    }

    public String getcode() {
        return code;
    }

    public void setcode(String code) {
        this.code = code;
    }

    public String getretailId() {
        return retailId;
    }

    public void setretailId(String retailId) {
        this.retailId = retailId;
    }
}

但我收到错误：

java.lang.ClassCastException: org.json.JSONObject cannot be cast to app.identity.UserIdentifier

我做错了什么？

编辑1：以下是从答案中使用gson的尝试：

Gson gson = new GsonBuilder().create();
String body = /*build request body*/;
String resourceResponse = operations.postForObject(/* url */, body, String.class);
JSONObject jsonResponse = new JSONObject(resourceResponse);
UserIdentifier userIdentifier = gson.fromJson(jsonResponse.getString("userIdentifier"), UserIdentifier.class);

但我收到错误：

org.json.JSONException: JSONObject["userIdentifier"] not a string.
    at org.json.JSONObject.getString(JSONObject.java:658) ~[json-20140107.jar:na]

Answer 1

您可能需要使用gson

   class Name{
String resultCode;
UserIdentifier useridentifier;
//getters

}

Gson gson=new Gson();
Name name=gson.fromJson(jsonString,Name.class);

Answer 2

找出问题所在。需要提取jsonobject而不是获取字符串。以下是解决问题的路线：

UserIdentifier userIdentifier = gson.fromJson(jsonResponse.getJSONObject("userIdentifier").toString(), UserIdentifier.class);

Answer 3

事情就是你不能像这样强制转换在get方法中返回的对象，一个解决方案就是这样，使用GSON库：

RestOperations operations = /*initalize*/;
String body = /*build request body*/;
Gson gson = new Gson();
String resourceResponse = operations.postForObject(/* url */, body, String.class);
JSONObject jsonResponse = new JSONObject(resourceResponse);
String jsonUserIdentifier = jsonResponse.getString("userIdentifier");
UserIdentifier userIdentifier = gson.fromJson(jsonUserIdentifier , UserIdentifier.class);

Answer 4

使用Gson库

Gson gson=new GsonBuilder().create();

UserIdentifier userIdentifier=gson.fromJson(jsonString,UserIdentifier.class);

在您的情况下，jsonString是 resourceResponse

详细研究Gson documentation

将JSONObject转换为Java对象

4 个答案: