Android Volley：BasicNetwork.performRequest：意外的响应代码404

Question

I want to get the user's information from database and display it, but I keep getting this error:

BasicNetwork.performRequest: Unexpected response code 404

Here's my javacode:

loading method:

public void loadUserProfile() {

    Response.Listener<String> responseListener = new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            try {
                JSONObject jsonResponse = new JSONObject(response);
                idTV.setText(jsonResponse.getString("_id"));
                nameTV.setText(jsonResponse.getString("name"));
                firstNameTV.setText(jsonResponse.getString("firstName"));
                emailTV.setText(jsonResponse.getString("email"));
                sexTV.setText(jsonResponse.getString("sex"));
                yearTV.setText(jsonResponse.getString("year"));
                cursusTV.setText(jsonResponse.getString("cursus"));
            } catch (JSONException e) {
                onLoadProfileFail();
            }
        }
    };
    ProfileRequest profileRequest = new ProfileRequest(user_id, responseListener);
    RequestQueue queue = Volley.newRequestQueue(ProfileActivity.this);
    queue.add(profileRequest);
}

Request class

class ProfileRequest extends StringRequest {
    private static final String USER_PROFILE_REQUEST = "http://[ipaddress]:8080/users/:id";
    private Map<String, String> params;

    public ProfileRequest(String id, Response.Listener<String> listener) {
        super(Method.POST, USER_PROFILE_REQUEST, listener, null);
        params = new HashMap<>();
        params.put("id", id);
    }

    @Override
    public Map<String, String> getParams() {
        return params;
    }
}

app.js

router.get('/users/:id', function(req, res) {
    User.find({ _id: "ie00847" }, function(err, user) {
      if (err)
          res.send(err);
      res.json(user);
    });
});

Answer 1

You got the 404 error since you're accessing a route with a method (POST) that is not available, because in the app.js file you defined a function for a get request rather than a POST request so you need to update the Android code to a GET request. Something like the following,

class ProfileRequest extends StringRequest {
    private static final String USER_PROFILE_REQUEST = "http://[ipaddress]:8080/users";
    private Map<String, String> params;

    public ProfileRequest(String id, Response.Listener<String> listener) {
        super(Method.GET, USER_PROFILE_REQUEST + "/" + id, listener, null);
    }
}

Also note that there is no need for overriding the getParams() method as you're not sending a POST request anymore. In addition, you can't add parameters to a GET request except through hard-coding the values in the URL and not through a Map object.

Hope this helps :)

Answer 2

You can resolve it by using this code

public void onErrorResponse(VolleyError error) {

                    NetworkResponse response = error.networkResponse;
                    if (response != null && response.statusCode == 404) {
                        try {
                            String res = new String(response.data,
                                    HttpHeaderParser.parseCharset(response.headers, "utf-8"));
                            // Now you can use any deserializer to make sense of data
                            JSONObject obj = new JSONObject(res);
                            //use this json as you want
                        } catch (UnsupportedEncodingException e1) {
                            // Couldn't properly decode data to string
                            e1.printStackTrace();
                        } catch (JSONException e2) {
                            // returned data is not JSONObject?
                            e2.printStackTrace();
                        }
                    }
                }