Volley JsonObjectRequest response

问题:

I'm retrieving data from my server through JSON using Volley JSONObjectRequest to achieve this. After getting the JSON response, I want to save it into a variable and use it through out the activity. Below is my code sample:

private String description;
private int status;
private boolean validateIntegrationCode() {
    if (checkNetwork()) {
        String url = "sample url";

        JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                try {
                    status = response.getInt("status");// ** STATUS IS 1 HERE **
                    description = response.getString("description");

                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                error.printStackTrace();
            }
        });

        mQueue.add(request);
    } else {
        // No network, check from SQLite
    }
    if (status == 1) { // ** STATUS IS 0 HERE **
        return true;
    } else {
        return false;
    }
}

When I check the status value before returning true or false, the value of status is now 0 and the description also returns null.

My JSON response:

{"status":1,"description":"Integration code is valid"}

回答1:

The volley request is an asynchronous call. It doesn't block the code till the response is received. So what is happening is your check for if(status==1) is happening before the volley response is received. Hence it is 0.

What you should do:

1) Make your function return type void.

2) In onResponse, put the code

if (status == 1) { // ** STATUS IS 0 HERE **
        statusBoolean = true;
    } else {
        statusBoolean = false;
}

回答2:

I have updated my answer as below,

    private int status;
    private String description;

    private void callRequest() {

        // Initialize a new RequestQueue instance
        RequestQueue requestQueue = Volley.newRequestQueue(MainActivity.this);

        // Initialize a new JsonObjectRequest instance
        JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(
                Request.Method.GET,
                "URL",
                null,
                new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {
                        try {
                            status = response.getInt("status");// ** STATUS IS 1 HERE **
                            description = response.getString("description");

                            checkStatus();
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        error.printStackTrace();
                    }
                }
        );

        // Add JsonObjectRequest to the RequestQueue
        requestQueue.add(jsonObjectRequest);
    }

    private void checkStatus(){
        if(status == 1){
            // do what do you need to do id status == 1
        }else{
            // do what do you need to do id status == 0
        }
    }

Try this and let me know the updates Thanks!

回答3:

You should declare status as int instead of String.

private int status=0;

You can try this way

                status = response.getInt("status");
                description = response.getString("description");
                if (status == 1) { 
                 checkingStatus(status);
                } else {
                 checkingStatus(status);
                }

Then

public void checkingStatus(int status){
        if(status == 1){
            // do your code
        }else{
            // do your code
        }
    }