I watched the google io ,and saw volley. But I don't know how to get start with it.
I've tried to clone https://android.googlesource.com/platform/frameworks/volley , but the test project keep warn me "resource directory does not exist" .
please give me some clue!
Set up the project as a library ( Project->Properties->Android->"Is Library" ).
Then, just create the res folder in Volley project, and eclipse will build the Volley.jar !
I found this to get start with.
I write this Test Project , and import com.android.volley and com.android.volley.toolbox from the volley library. And it works ^_^
protected static final String TAG = "com.gyh.myvolleytest";
public static final String url = "http://192.168.1.108:8080/httptest/servlet/mainservlet?name=stack&age=23";
public static Response.ErrorListener createErrorListener() {
return new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.d(TAG, "Error Response code: " + error.getMessage());
}
};
}
public static Response.Listener<String> createSuccessListener() {
return new Response.Listener<String>() {
#Override
public void onResponse(String response) {
// TODO parse response
String string = response.toString();
Log.d(TAG, "string :" + string);
}
};
}
public static Response.Listener<JSONObject> createJsonListener() {
return new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
String jsonStr = response.toString();
Log.d(TAG, "jsonStr :" + jsonStr);
System.out.println(jsonStr);
}
};
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void click(View view) {
RequestQueue queue = Volley.newRequestQueue(this);
// JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET,
// url, null, createJsonListener(), createErrorListener());
StringRequest request = new StringRequest(Request.Method.GET, url,
createSuccessListener(), createErrorListener());
queue.add(request);
queue.start();
}
Hope this can help ^_^
Related
I am working with volley library in my android app development.
I have a base url and I need to append some value at the end of the url,click here,
So, this value "ZGxb87HuJK" keeps changing dynamically in my program and need to append this value at the end of url. How to add this in params?
Use this way.
StringRequest strreq = new StringRequest(Request.Method.GET,
"https://sample.com/testing/" + Hear Your dynamic value,
new Response.Listener<String>() {
#Override
public void onResponse(String Response) {
// get response
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError e) {
e.printStackTrace();
}
});
Volley.getInstance(this).addToRequestQueue(strreq);
String URL = "https://sample.com/testing/" + "dynamic value e.g ZGxb87HuJK";
JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.GET,
URL, null,
new Response.Listener() {
#Override
public void onResponse(JSONObject response) {
//Success Callback
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
//Failure Callback
}
});
// Adding the request to the queue along with a unique string tag
MyApplication.getInstance().addToRequestQueue(jsonObjectReq, "getRequest");
Change your code like this
So I've run into a problem in my code, where I need to get a JSONString from my server with volley. And then I have to parse the String into a JSONObject and then continue doing stuff with that.
My problem here is, that Volley gives the response too late, meaning my string that I want to parse is always empty because its not initialised yet.
RequestFuture<String> future = RequestFuture.newFuture();
StringRequest stringRequest = new StringRequest(Request.Method.GET, searchURLBuilder, future, future);
// new Response.Listener<String>() {
// #Override
// public void onResponse(String response) {
// writeToSharedResponse(response_for_search, response);
// }
// },
// new Response.ErrorListener() {
// #Override
// public void onErrorResponse(VolleyError error) {
// Log.d("Error!!:" + error.getMessage(), "");
// }
// });
requestQueue.add(stringRequest);
String response = "";
try {
response = future.get(60, TimeUnit.SECONDS);
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
} catch (TimeoutException e) {
e.printStackTrace();
}
String responseString = m.getString(response_for_search, new String());
pieceDTOList = getPiecesDTOFromJSON(responseString);
Here is a snippet of my code. As you can see I already tried to make a "future" call to block and wait for the answer, but it just times out every time. The commented out bit, is the part I actually wanted to use from the beginning, but that returns the response to late. Since its asynchronous and accesses the server w/e it wants.
writeToSharedResponse just writes the answer into a sharedPreferences variable.
private SharedPreferences m;
private SharedPreferences.Editor editor;
private RequestQueue requestQueue;
public DbParser(Context c) {
m = PreferenceManager.getDefaultSharedPreferences(c);
editor = m.edit();
requestQueue = Volley.newRequestQueue(c);
}
My Question here is: Is there an easy way I can "wait" for the answer from volley so I can continue to work with the response that I get?
Edit 1:
I now added an interface and changed the code around to this:
getString(new VolleyCallback() {
#Override
public void onSuccess(String result) {
getPiecesDTOFromJSON(result);
}
}, searchURLBuilder);
return globalPieceDTOList;
}
private void getString(final VolleyCallback callback, String searchUrl){
StringRequest stringRequest = new StringRequest(Request.Method.GET, searchUrl,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
callback.onSuccess(response);
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.d("Error!!:" + error.getMessage(), "");
}
});
requestQueue.add(stringRequest);
}
Since I cant get the values out of my inner classes, I did a nasty hack and created a global list for my DTO's. The problem now is that "return globalPieceDTOList" is always Null. And again - I would need to "wait" for the Volley response.
Volley requests are async, so when you try to return a value, the request is likely not done yet. If you want to return values from a Volley request use callback interfaces.
Example
public void getString(final VolleyCallback callback) {
StringRequest strReq = new StringRequest(Request.Method.GET, url, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
// do some things here
callback.onSuccess(<PASS STRING RESULT HERE>);
}
});
}
public interface VolleyCallback{
void onSuccess(String result);
}
Example usage:
public void onResume(){
super.onResume();
getString(new VolleyCallback(){
#Override
public void onSuccess(String result){
//do stuff here with the result from the volley request
}
});
}
I'm using getConnection method in my program and I want to restore the response in a variable like "String result " in-order to use in another class, but I don't know how I must change the method. Does anyone have an idea?.
public class Webservice {
public static void getConnection(Context context, String url){
RequestQueue queue = Volley.newRequestQueue(context);
StringRequest stringRequest = new StringRequest(Request.Method.GET, url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.i("TEST", "Response is: "+ response);
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.i("TEST","That didn't work!");
}
});
queue.add(stringRequest);
}
}
You can create a variable in Application class and use it throughout your application like this
public class App extends android.app.Application {
private static App instance;
public static String resultResponse;
public static App getInstance() {
return instance;
}
#Override
public void onCreate() {
super.onCreate();
instance = this;
}
}
Then when you get the response save it like this
public class Webservice {
public static void getConnection(Context context, String url){
RequestQueue queue = Volley.newRequestQueue(context);
StringRequest stringRequest = new StringRequest(Request.Method.GET,
url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.i("TEST", "Response is: "+ response);
App.getInstance().resultResponse = response;
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.i("TEST","That didn't work!");
}
});
queue.add(stringRequest);
}
}
Add
android:name = ".App"
in Application in your manifest.
Now Use
App.getInstance().resultResponse
where ever you want through out your Application.
You can use interface having return type String in onResponse method and implement this interface in your required class get String response.
i'm trying to use simple Volley JsonObjectRequest fro web service but i get this error:
error: reference to JsonObjectRequest is ambiguous, both constructor JsonObjectRequest(int,String,String,Listener<JSONObject>,ErrorListener) in JsonObjectRequest and constructor JsonObjectRequest(int,String,JSONObject,Listener<JSONObject>,ErrorListener) in JsonObjectRequest match
i'm install volley from Gradle and this is my simple code which i'm using in project.
public class Simple_JsonRequest extends Activity {
private TextView mTvResult;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act__json_request);
mTvResult = (TextView) findViewById(R.id.tv_result);
Button btnJsonRequest = (Button) findViewById(R.id.btn_json_request);
btnJsonRequest.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
RequestQueue queue = MyVolley.getRequestQueue();
JsonObjectRequest myReq = new JsonObjectRequest(Request.Method.GET,
"http://echo.jsontest.com/key/value/one/two",
null,
createMyReqSuccessListener(),
createMyReqErrorListener());
queue.add(myReq);
}
});
}
private Response.Listener<JSONObject> createMyReqSuccessListener() {
return new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
try {
mTvResult.setText(response.getString("one"));
} catch (JSONException e) {
mTvResult.setText("Parse error");
}
}
};
}
private Response.ErrorListener createMyReqErrorListener() {
return new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
mTvResult.setText(error.getMessage());
}
};
}
}
How about you replace the null which is the 3rd argument, with something more specific and then try ?
Because JsonObjectRequest have two constructors,
one is
JsonObjectRequest(int,String,JSONObject,Listener<JSONObject>,ErrorListener)
and another is
JsonObjectRequest(int,String,String,Listener<JSONObject>,ErrorListener),so if you set the third parameter to null,the compiler won't know which constructor you want to use,so such an error occurred.
To solve your problem,you just can replace your third parameter to new JSONObject() or "".
I want to pass a response outside of my classes (many classes)
public static void userLocation()
{
RequestQueue queue = Volley.newRequestQueue(context);
String url = "http://www.jobdiagnosis.com/iphone/userlocation.php";
StringRequest dr = new StringRequest(Request.Method.GET, url,
new Response.Listener<String>()
{
#Override
public void onResponse(String response) {
// response
//Toast.makeText(context, ""+response, Toast.LENGTH_LONG).show();
}
},
new Response.ErrorListener()
{
#Override
public void onErrorResponse(VolleyError error) {
// error.
// Toast.makeText(getApplicationContext(), "error"+error, Toast.LENGTH_LONG).show();
Log.d("error", ""+error);
}
}
);
queue.add(dr);
}
Please suggest how I can pass a response outside of the class
In volly its difficult to return response outside the class.because request on server run in background and if we return value followed by queue.add(url) then it will return null.So there is no solution till now.Thanks!!