问题
I am fetching json data through Volley. The problem I am having
is that Volley's onResponse is never called, and hence the data are not parsed and displayed.
Sample JSON data
{
"title": "This is a sample text title title",
"cat": {
"origin" : "United states",
"target" : "Asia",
},
"content": "Lorem ipsum ipsum trxt hag jlak jshss jsyts pjqgq uuqtyq usiuqjo uwywh",
}
NewsActivity
public class NewsDetails extends AppCompatActivity {
private final String TAG = "NewsDetails";
private ProgressDialog mProgresscircle;
TextView newsTitle, newsOrigin, newsContent;
//private int news_id;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_news_details);
newsTitle = (TextView) findViewById(R.id.dnews_title);
newsOrigin = (TextView) findViewById(R.id.dnews_origin);
newsContent = (TextView) findViewById(R.id.dnews_content);
if (NetworkCheck.isAvailableAndConnected(this)) {
//Calling method to load newss
loadNews();
} else {
final Context context;
context = this;
final AlertDialog.Builder alertDialog = new AlertDialog.Builder(this);
alertDialog.setTitle(R.string.alert_titl);
alertDialog.setCancelable(false);
alertDialog.setIcon(R.mipmap.ic_launcher);
alertDialog.setMessage(R.string.failed_news);
alertDialog.setPositiveButton(R.string.alert_retry, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
if (!NetworkCheck.isAvailableAndConnected(context)) {
alertDialog.show();
} else {
loadNews();
}
}
});
alertDialog.setNegativeButton(R.string.alert_cancel, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
finish();
}
});
alertDialog.show();
}
}
private void loadNews() {
Log.d(TAG, "loadNews called");
mProgresscircle = new ProgressDialog(NewsDetails.this);
mProgresscircle.setCancelable(false);
mProgresscircle.setMessage(null);
mProgresscircle.show();
int news_id = getIntent().getIntExtra("NewsId", -1);
Toast.makeText(NewsDetails.this, "News id is" + news_id, Toast.LENGTH_SHORT).show();
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(DetailConfig.GET_DURL + news_id,
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
Log.d(TAG, "onResponse called NewsDetails");
//Dismissing progressbar;
if (mProgresscircle != null) {
mProgresscircle.dismiss();
}
//Calling method to parse json array
parseNews(response);
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
});
//Creating request queue
RequestQueue requestQueue = Volley.newRequestQueue(this);
//Adding request to queue
requestQueue.add(djsonArrayRequest);
}
//This method will parse json data of news
private void parseNews(JSONArray jsonArray) {
Log.d(TAG, "Parsing news array");
for (int i = 0; i<jsonArray.length(); i++) {
JSONObject jsonObject = null;
try {
jsonObject = jsonArray.getJSONObject(i);
String title = jsonObject.getString(DetailConfig.TAG_DPOST_TITLE);
newsTitle.setText(title);
JSONObject pOrigin = jsonObject.getJSONObject("cat");
String origin = pOrigin.getString("origin");
newsOrigin.setText(origin);
String content = jsonObject.getString(DetailConfig.TAG_DPOST_CONTENT);
newsContent.setText(content);
} catch (JSONException w) {
w.printStackTrace();
}
}
}
}
The things I know
- In logcat, loadNews method is called.
- I'm logging Volley, and from logcat volley is not complaining in anyway
- I can't see "onResponse called NewsDetails" in logcat, meaning that for some reason not known to me, it's not called
So, my question is why is onResponse not called and how should I fix it?
回答1:
/* you are getting json in response but your response listener method is get Json Array replace your code with below code and also add an debug point in your error listener method */
private void loadNews() {
Log.d(TAG, "loadNews called");
mProgresscircle = new ProgressDialog(NewsDetails.this);
mProgresscircle.setCancelable(false);
mProgresscircle.setMessage(null);
mProgresscircle.show();
int news_id = getIntent().getIntExtra("NewsId", -1);
Toast.makeText(NewsDetails.this, "News id is" + news_id, Toast.LENGTH_SHORT).show();
final JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.POST,
DetailConfig.GET_DURL, requestParam,
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
Log.d("Debug", response.toString());
//TODO parsing code
parseNews(response);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d("", "Error: " + error.getMessage());
}
});
//Creating request queue
RequestQueue requestQueue = Volley.newRequestQueue(this);
//Adding request to queue
requestQueue.add(djsonArrayRequest);
}
// or replace this code into your into your loadNews method
final JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.POST,
DetailConfig.GET_DURL, requestParam,
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
Log.d("Debug", response.toString());
//TODO parsing code
parseNews(response);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d("", "Error: " + error.getMessage());
}
});
**
You can also refer below link for complete tutorial http://www.hackpundit.com/android-turorial-json-parse-volley/
**
回答2:
You should use JsonObjectRequest instead of JsonArrayRequest because you are getting jsonobject in the response. For getting more knowledge you may go through Volley tutorial
来源：https://stackoverflow.com/questions/36614675/why-is-volleys-onresponse-not-called