使用Retrofit2从API调用获得错误响应

Question

I want to make a call to the API and the error response comes in two ways.

First is like this (where the message is an object with multiple string lists)

{
  "success": false,
  "message": {
    "email": [
        "Must be between 2 and 20 characters."
    ],
    "password": [
        "Must be between 2 and 25 characters."
    ]
  }
}

And the other is like this (where message is just a string)

{
  "success": false,
  "message": "User with that email exists."
}

My model so far looks like this:

public class ErrorResponse {

    @Expose
    @SerializedName("success")
    private boolean success;


    @Expose
    @SerializedName("message")
    private Message message;

    //constructor & getters & setters

    public class Message {

        @Expose
        @SerializedName("email")
        private List<String> email;

        @Expose
        @SerializedName("password")
        private List<String> password;

        //constructor & getters & setters
    }
}

How can I treat both cases of "message" in model class?

Answer 1

简单的方法是在客户端中使用ErrorMessage属性并通过成功标志句柄呈现。

Answer 2

If this two pattern are fix then you can try below way :

ErrorResponse.java

public class ErrorResponse {

@Expose
@SerializedName("success")
private boolean success;


@Expose
@SerializedName("message")
private MyMessage message;

public class MyMessage{

 private Message message;

 private String StrMessage;

}

//constructor & getters & setters

public class Message {

    @Expose
    @SerializedName("email")
    private List<String> email;

    @Expose
    @SerializedName("password")
    private List<String> password;

    //constructor & getters & setters
}
}

And when you want to use their value just check which kind of value it is like below.

if(StrMessage!=null){
//Message is string.
}
else{
//do your stuff. 
}

Answer 3

You should parse your JSON manually, For example if your JSON has message and your message has email tag then using the second model and if not using the first model, it works only if you have this two kind of messages.

something like this using Gson:

JsonElement rootTree = parser.parse(jsonRequest);
        if (rootTree.isJsonObject()) {

         JsonObject object = rootTree.getAsJsonObject();
         JsonElement message= object.get("message");

         if(message.isJsonObject()) {
                JsonElement email = message.get("email");

                if(email != null) {
                          //Use second model
                } else {
                          //Use first model                     
                }
         }
}

Answer 4

You can try something like this,

       JSONObject json = new JSONObject(response);
        if (json.has("message")) {
            if (json.get("message") instanceof String) {
                message = json.getString("message");
            } else if (json.get("message") instanceof JSONObject) {
                JSONObject jsonObject = json.getJSONObject("message");
                if (jsonObject.has("email")) {
                    JSONArray array = jsonObject.getJSONArray("email");
                    for (int i = 0; i < array.length(); i++) {
                        email.add(array.getString(i));
                    }
                }
                if (jsonObject.has("password")) {
                    JSONArray array = jsonObject.getJSONArray("password");
                    for (int i = 0; i < array.length(); i++) {
                        password.add(array.getString(i));
                    }
                }
            }
        }

Don't forget to handle JSONException.

Answer 5

Try this, It is working for me. and it's a easiest way to handle this kind of response.

API request using ResponseBody,

Call<ResponseBody> call = .......

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

                try {
                    if (response.body() != null && response.body().string() != null) {

                        Object json = new JSONTokener(response.toString()).nextValue();

                        if (json instanceof JSONArray) {
                            MyResponse1 myResponse = new Gson().fromJson(response.body().string(), MyResponse1.class);
                            myResponse.getMessage().getEmail();
                        } else if (json instanceof JSONObject) {

                            MyResponse2 myResponse = new Gson().fromJson(response.body().string(), MyResponse2.class);
                            myResponse.getMessage();
                        }

                    }
                } catch (IOException e) {
                    e.printStackTrace();
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }

            @Override
            public void onFailure(Call<ResponseBody> call, Throwable t) {
                // Handle exception here
            }
        });

Take two object class for two different response:

// MyResponse1.java

public class MyResponse1 {


    private boolean success;
    private MessageBean message;

    public boolean isSuccess() {
        return success;
    }

    public void setSuccess(boolean success) {
        this.success = success;
    }

    public MessageBean getMessage() {
        return message;
    }

    public void setMessage(MessageBean message) {
        this.message = message;
    }

    public static class MessageBean {
        private List<String> email;
        private List<String> password;

        public List<String> getEmail() {
            return email;
        }

        public void setEmail(List<String> email) {
            this.email = email;
        }

        public List<String> getPassword() {
            return password;
        }

        public void setPassword(List<String> password) {
            this.password = password;
        }
    }
}

// MyResponse2.java

public class MyResponse2 {


    private boolean success;
    private String message;

    public boolean isSuccess() {
        return success;
    }

    public void setSuccess(boolean success) {
        this.success = success;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}