Question

我正在上课

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;
}

我有json字符串，

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

我想将这个json字符串分配给上面的类。我使用GSON将json字符串分配给java对象。在普通类中，我可以将json字符串分配给java对象。但是对于这门课我不能直接分配。请任何人帮助我，现在我指的是，

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

Answer 1

您可以使用sourceforge中的JavaJson。您可以将json字符串传递给JsonObject .parse()。

试试这个

 JsonObject json = JsonObject .parse("{\"OperationResult\":0, \"Messages\":\"UpdateAvailable\"");
 System.out.println("OperationResult=" + json.get("OperationResult"));
 System.out.println("Messages=" + json.get("Messages"));

https://sourceforge.net/projects/javajson/

Answer 2

由于您的Java类不以任何方式，形状或形式与您的JSON相似......您将遇到问题。

问题＃1：OperationResult应该是int
问题＃2：你被宣布为ResultData为Object ... Java不能像那样工作。

你需要你的POJO匹配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);

我还考虑使用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;

Answer 3

试试这个：

java.lang.reflect.Type  type = new TypeToken<ReturnData>(){}.getType();
ReturnData rd = new Gson().fromJson(jsonString, type);

Json字符串到java对象

3 个答案: