android - 在改造 2.0 中处理 JSON 响应

Question

我知道这是老问题或重复问题。但我不知道我哪里错了。我从这个 JSON 得到的结果为 null。

{
"error": {
    "dateTimeUtc": "2017-12-26T05:46:05.1126801+00:00",
    "errorReference": "sample string 2",
    "errorType": "Error",
    "title": "sample string 3",
    "code": "sample string 4",
    "messages": [
      "sample string 1",
      "sample string 2"
    ]
  },
  "result": {
    "message": "sample string 1"
  }
}

我有这种类型的 JSON 可以从 Retrofit2 中读取。我创建了一个名为 RetrofitResponce

的 POJO 类

private Error error;
private Result result;
public Result getResult ()
{
    return result;
}

public void setResult (Result result)
{
    this.result = result;
}

public Error getError ()
{
    return error;
}

public void setError (Error error)
{
    this.error = error;
}

@Override
public String toString()
{
    return "ClassPojo [result = "+result+", error = "+error+"]";
}`

现在在 call.enque() 方法中处理响应，比如

call.enqueue(new Callback<RegisterUser>() {
        @Override
        public void onResponse(Call<RetrofitResponce> call, Response<RetrofitResponce> response) {

            try {
                RetrofitResponce retrofitResponce= response.body();

                Error error = retrofitResponce.getError();
                Result result=retrofitResponce.getResult();


                Log.e("Eroor", "rr  " + error.getTitle().toString());
            } catch (Exception e) {

            }
        }

        @Override
        public void onFailure(Call<RetrofitResponce> call, Throwable t) {
            Log.e("Failure ", "fail " + t.toString());
        }
    });

但在这里我得到 NullPointerException，即我在 RestrofitResponce 中没有得到任何响应。 Error 和 Result 都为 Null。

java.lang.NullPointerException: Attempt to invoke virtual method 'net.xyz.abc.Model.Error net.xyz.abc.Model.RegisterUser.getError()' on a null object reference

请帮帮我。尝试解决我的问题。提前致谢。

postman 响应，

{
"error": {
    "dateTimeUtc": "2017-12-26T07:05:51.1427712Z",
    "errorReference": "00000000-0000-0000-0000-000000000000",
    "errorType": "Error",
    "title": "The request is invalid.",
    "code": null,
    "messages": [
        "Passwords must have at least one non letter or digit character. Passwords must have at least one uppercase ('A'-'Z')."
    ]
},
"result": null

Answer 1

Retrofit callback需要response model，改成这样:

call.enqueue(new Callback<RetrofitResponce>() {
        @Override
        public void onResponse(Call<RetrofitResponce> call, Response<RetrofitResponce> response) {


                if (response.isSuccessful()) {
                RetrofitResponce retrofitResponce= response.body();
                if (retrofitResponce!=null) {   
                Error error = retrofitResponce.getError();
                Result result=retrofitResponce.getResult();       
                Log.e("Eroor", "rr  " + error.getTitle().toString());
              }
            }                
        }

        @Override
        public void onFailure(Call<RetrofitResponce> call, Throwable t) {
            Log.e("Failure ", "fail " + t.toString());
        }
    });

编码愉快!!