Json字符串到java对象 [英] Json string to java object

问题描述

  public class ReturnData {
 public ReturnData（）{
 OperationResult = Result.Failed; 
 Messages =发生错误; 
 UpdateAvailable =0; 
 ResultData =; 
} 
 
 public Result OperationResult; 
 public String Messages; 
 public String UpdateAvailable; 
 public Object ResultData; 
} 
  

我有类似json的字符串，

  {OperationResult：0，Messages：，UpdateAvailable：，ResultData：{SessionId：3b44a524-fc2a -499b-A16E-6d96339a6b5b， 用户名： 管理， AccoundId：空， 角色： 管理员]， 显示名称： 管理， 状态：3， 类型： 1}} 
  

我想将这个json字符串分配给上面的类。我使用GSON进行赋值json字符串到java对象。在普通的类我可以分配json字符串到java对象。但是对于这个班级我不能直接分配。请任何人帮助我，
现在我分配像，

 字符串formatedjsonstring = {json string}; 
 Log.i（FORMAT STRING：，formatedjsonstring）; 
 Gson gson = new Gson（）; 
 ReturnData returndata =（ReturnData）gson.fromJson（
 formatedjsonstring，ReturnData.class）; 
  

解决方案

由于您的Java类不像您的JSON任何方式，形状或形式...你会有一个问题。

• 问题＃1： OperationResult 应该是 int


• 问题＃2：将 ResultData 声明为 Object ... Java无法正常工作。

您需要POJO来匹配JSON：

  public class ReturnData {
 public ReturnData（）{
 OperationResult = Result.Failed; 
 Messages =发生错误; 
 UpdateAvailable =0; 
 ResultData =; 
} 
 
 public int OperationResult; 
 public String Messages; 
 public String UpdateAvailable; 
 public MyResultData ResultData; 
} 
 
 class MyResultData {
 public String SessionId; 
 public String UserName; 
 public String AccountId; 
 public List< String>角色; 
 public String DisplayName; 
 public int Status; 
 public int类型; 
} 
 
 ReturnData rd = new Gson（）。fromJson（jsonString，ReturnData.class）; 
  

我也考虑使用Gson的 @SerializedName（name）注释将JSON中的PascalCase字段名称转换为Java中的camelCase字段名称。

  @SerializedName（OperationResult）public int operationResult; 
  

I'm having following class

public class ReturnData {
    public ReturnData() {
        OperationResult = Result.Failed;
        Messages = "An Error Occured";
        UpdateAvailable = "0";
        ResultData = "";
    }

    public Result OperationResult;
    public String Messages;
    public String UpdateAvailable;
    public Object ResultData;
}

I'm having json string like,

{"OperationResult":0,"Messages":"","UpdateAvailable":"","ResultData":{"SessionId":"3b44a524-fc2a-499b-a16e-6d96339a6b5b","UserName":"admin","AccoundId":null,"Roles":["Administrator"],"DisplayName":"Admin","Status":3,"Type":1}}

I want to assign this json string to above class.I'm using GSON for assign json string to java object.In normal class i can assign json string to java object. But for this class i couldn't assign directly. Please any one help me, Now i'm assigning like,

String formatedjsonstring = {json string};
            Log.i("FORMAT STRING:",formatedjsonstring);
            Gson gson = new Gson();
            ReturnData returndata = (ReturnData) gson.fromJson(
                    formatedjsonstring, ReturnData.class);

解决方案

Since your Java class doesn't resemble your JSON in any way, shape or form ... you're going to have a problem with that.

• Problem #1: OperationResult should be an int
• Problem #2: You're declared ResultData as an Object ... Java doesn't work like that.

You need your POJO to match the JSON:

public class ReturnData {
    public ReturnData() {
        OperationResult = Result.Failed;
        Messages = "An Error Occured";
        UpdateAvailable = "0";
        ResultData = "";
    }

    public int OperationResult;
    public String Messages;
    public String UpdateAvailable;
    public MyResultData ResultData;
}

class MyResultData {
    public String SessionId;
    public String UserName;
    public String AccountId;
    public List<String> Roles;
    public String DisplayName;
    public int Status;
    public int Type;
}

ReturnData rd = new Gson().fromJson(jsonString, ReturnData.class);

I'd also consider using Gson's @SerializedName("name") annotation to convert the PascalCase field names in your JSON to camelCase field names in Java.

@SerializedName("OperationResult") public int operationResult;

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