Develop Reference

How to create a single volley webservice class to use across the android app?

My android application uses multiple network calls in a single activity and i have several of these activities where i have to use both post and get requests. I want to create a single "VolleyWebservice" class and call the same in multiple activities instead of writing the complete volley code. I am relatively new to android development and i don't understand where i am going wrong.
public class VolleyWebService {
public JSONObject result;
public JSONObject getResponse(String url, Context mContext) {
RequestQueue mQueue = Volley.newRequestQueue(mContext);
JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
Log.e(TAG, "Anshuman" + response.toString());
result = response;
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
}
});
mQueue.add(request);
return result;
}
}
The method in My activity where i am calling this class
private void callFunctionGetDist() {
ProgressDialog progressDialog;
progressDialog = ProgressDialog.show(recorddata.this, "", "Please Wait...", true);
JSONObject response = new VolleyWebService().getResponse(urlConfigClass.GET_DISTRICT, this);
try {
if(response.toString().contains("Status:Success,Details")){
arrDistName.clear();
arrDistCode.clear();
arrDistName.add("Select District Name");
arrDistCode.add("Select District Code");
JSONArray jsonArray = response.getJSONArray("Status:Success,Details");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jobJ = jsonArray.getJSONObject(i);
String scheName = jobJ.getString("post");
JSONObject jobJDist = new JSONObject(scheName);
String distname = jobJDist.getString("District");
String distcode = jobJDist.getString("DistrictCode");
arrDistName.add(distname);
arrDistCode.add(distcode);
}
ArrayAdapter<String> dataAdapter = new ArrayAdapter<>(recorddata.this,
R.layout.custom_textview_to_spinner, arrDistName);
// Drop down layout style - list view with radio button
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// attaching data adapter to spinner
district.setAdapter(dataAdapter);
progressDialog.dismiss();
}else{
progressDialog.dismiss();
Toast.makeText(getApplicationContext(), "Response is null or empty", Toast.LENGTH_LONG).show();
}
} catch (Exception volleyError) {
progressDialog.dismiss();
Toast.makeText(getApplicationContext(), volleyError.getMessage(), Toast.LENGTH_LONG).show();
}
}
I tried creating the same class but i am not able to get the response to other activities. Although i am getting the correct response in the Volley jsonbject response, the response return null in other activities.
I want to have the result object return the response in my recorddata activity
This is what i have tried so far, no luck though!
public void postResponse (String url, Context mContext, final VolleyResponseListener listener) {
try {
String encodedUrl = url.replace(" ", "%20") + "";
if (encodedUrl.contains("("))
encodedUrl = encodedUrl.replace("(", "%28");
if (encodedUrl.contains(")"))
encodedUrl = encodedUrl.replace(")", "%29");
encodedUrl = encodedUrl.replace(" ", "%20");
RequestQueue mQueue = Volley.newRequestQueue(mContext);
JsonObjectRequest request = new JsonObjectRequest(Request.Method.POst, encodedUrl, null, new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
Log.e(TAG, "Anshuman" + response.toString());
listener.onSuccess(response);
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
listener.onError(error);
}
}) {
#Override
protected Map<String, String> getParams() {
return new HashMap<>();
}
};
mQueue.add(request);
} catch (Exception e) {
e.printStackTrace();
}
}

For the sake of achieving your goal, (without taking in to consideration architecture and coding principles), you can pass a callback:
public class VolleyWebService {
public interface VolleyResponseListener {
void onSuccess(JSONObject response);
void onError(VolleyError error);
}
public JSONObject result;
public JSONObject getResponse(String url, Context mContext, VolleyResponseListener listener) {
RequestQueue mQueue = Volley.newRequestQueue(mContext);
JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
Log.e(TAG, "Anshuman" + response.toString());
listener.onSuccess(response);
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
listener.onError(error);
}
});
mQueue.add(request);
return result;
}
}
To use it:
volleyWebService.getResponse("your url", context, new VolleyResponseListener() {
#Override
void onSuccess(JSONObject response) {
//do what you want on success
}
#Override
void onError(VolleyError error) {
//do what you want on error
}
});

Show function data without blinking with Volley in Android Studio

Recently I am working on Android project with Volley for registration and for further operation, I can make function for insertion and other one is for retrieval data. When insert button click 'Insert' function called and data has been inserted to database through volley, and at the same time retrieval function also called. But when USER clicked the button and function called then data showed(database inserted data) with blinking effect, look like loading.
I want to get rid of that effect. I want to show data smoothly without any blinking effect. I do searching but can not find any solution. Please suggest me solution I'am newbie so kindly short and efficient required.
package com.darkcoderz.parsejson;
public class MainActivity extends AppCompatActivity {
private Context mContext;
private Activity mActivity;
//private CoordinatorLayout mCLayout;
private TextView mTextView;
private String mJSONURLString = "http://192.168.10.4/volley/api.php";
String url = "http://192.168.10.4/volley/register.php";
private EditText sms;
private Button sendsms;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Get the application context
//mContext = getApplicationContext();
//mActivity = MainActivity.this;
// Get the widget reference from XML layout
//mCLayout = (CoordinatorLayout) findViewById(R.id.coordinator_layout);
mTextView = (TextView) findViewById(R.id.tv);
sms = (EditText) findViewById(R.id.sms);
sendsms = (Button) findViewById(R.id.sendsms);
final Handler firesms = new Handler();
firesms.post(new Runnable() {
#Override
public void run() {
getdata();
firesms.postDelayed(this, 100);
}
});
sendsms.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
reg();
}
});
getdata();
}
// insert
public void reg()
{
final String msg = sms.getText().toString();
StringRequest stringreq = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
if (response.equals("success"))
{
Toast.makeText(MainActivity.this, "Registration Successfull!", Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(MainActivity.this, "Username Already Exist!", Toast.LENGTH_SHORT).show();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(MainActivity.this, "Great Error "+error.toString(), Toast.LENGTH_LONG).show();
}
})
{
#Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String,String> params = new HashMap<>();
params.put("sms",msg);
return params;
}
};
RequestQueue reqest = Volley.newRequestQueue(MainActivity.this);
reqest.add(stringreq);
}
private void getdata() {
// Empty the TextView
mTextView.setText("");
// Initialize a new RequestQueue instance
RequestQueue requestQueue = Volley.newRequestQueue(MainActivity.this);
// Initialize a new JsonArrayRequest instance
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(Request.Method.GET, mJSONURLString, null, new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
// Do something with response
//mTextView.setText(response.toString());
// Process the JSON
try{
// Loop through the array elements
for(int i=0;i<response.length();i++){
// Get current json object
JSONObject student = response.getJSONObject(i);
// Get the current student (json object) data
// String firstName = student.getString("fname");
// String lastName = student.getString("lname");
String age = student.getString("email");
// Display the formatted json data in text view
mTextView.append("SMS : " + age);
mTextView.append("\n\n");
}
}catch (JSONException e){
e.printStackTrace();
}
}
},
new Response.ErrorListener(){
#Override
public void onErrorResponse(VolleyError error){
// Do something when error occurred
Toast.makeText(mContext, "Something Went Wrong", Toast.LENGTH_SHORT).show();
}
}
);
// Add JsonArrayRequest to the RequestQueue
requestQueue.add(jsonArrayRequest);
}
}

private void getdata() {
// Empty the TextView
mTextView.setText("");
// Initialize a new RequestQueue instance
RequestQueue requestQueue = Volley.newRequestQueue(MainActivity.this);
// Initialize a new JsonArrayRequest instance
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(Request.Method.GET, mJSONURLString, null, new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
//before parsing check your response is in JSONArray Format or JSONObject format
// Process the JSON
try{
}catch (JSONException e){
e.printStackTrace();
//print here to know JSONException if exists
Toast.makeText(mContext, "Exception"+e.toString(), Toast.LENGTH_SHORT).show();
}
}
}
},
new Response.ErrorListener(){
#Override
public void onErrorResponse(VolleyError error){
// Do something when error occurred
Toast.makeText(mContext, "Something Went Wrong", Toast.LENGTH_SHORT).show();
}
}
);
// Add JsonArrayRequest to the RequestQueue
requestQueue.add(jsonArrayRequest);
}

android studio getting data from php database and populating the activity

i'm trying to get the data from the database to fill the activity with them but i'm not getting anything this is the db code i have 2 Textvies 1 image view i'm trying to fill with the data i'm new to mobile programming so need help:
public void gettypedet(final int tid, final TextView ttitle, final ImageView timg, final TextView desc) {
String url = "http://192.168.0.114/mobileshop/product_typrbyid.php?id="+tid;
// Instantiate the RequestQueue.
RequestQueue queue = Volley.newRequestQueue(context);
// Request a json response from the provided URL.
JsonObjectRequest jsonRequest = new JsonObjectRequest(Request.Method.GET, url,
new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject prt) {
try {
String type=prt.getString("type");
int imgname=Integer.parseInt(prt.getString("imagename"));
String des=prt.getString("description");
ttitle.setText(type);
timg.setImageResource(imgname);
desc.setText(des);
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.i("error", error.toString());
}
});
// Add the request to the RequestQueue.
queue.add(jsonRequest);
}
this is my php code i tested it and it's working so shouldn't be the problem:
<?php
require_once("connection.php");
$id=$_GET["id"];
$q="Select * from product_type where id='$id'";
$res=mysqli_query($con,$q);
while($row=mysqli_fetch_assoc($res)){
$types[]=$row;
}
echo (json_encode($types));
mysqli_free_result($res);
?>
this is the activity code here not sure if i did something wrong:
public class ptype_detail extends Activity {
int kposition,tposition,id;
TextView ttitle,tdes;
ImageView timg;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_ptype_detail);
tposition=(Integer)getIntent().getExtras().get("tpos");
kposition=(Integer)getIntent().getExtras().get("kpos");
if (kposition==0)
id=tposition+5;
else if(kposition==1)
id=tposition+18;
else if (kposition==2)
id=tposition+20;
else
id=tposition;
ttitle=(TextView)findViewById(R.id.title) ;
tdes=(TextView)findViewById(R.id.typedes);
timg=(ImageView)findViewById(R.id.titleimage);
shop db=new shop(this);
db.gettypedet(id,ttitle,timg,tdes);
}
}

How to get Volley POST response body?

I am using simmilar fucntion for creating GET and POST api requests, but the GET function set textview to response body and I dont know how to read the status code and the POST function set textview to the response code and I dont know how to read response body. Can you help me, please?
I also tried to log in parseNetworkResponse() response.data.toString() but thats is not the data that api returns. Maybe I need to encode it somehow?
public void createGet(Context context, String url) {
final TextView apiResultTextview = (TextView) ((Activity)
context).findViewById(R.id.api_result_textview);
// Instantiate the RequestQueue.
RequestQueue queue = Volley.newRequestQueue(context);
// Request a string response from the provided URL.
StringRequest stringRequest = new StringRequest(Request.Method.GET, url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
// Display the first 500 characters of the response string.
apiResultTextview.setText("Response is: " + response.substring(0, 50));
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
apiResultTextview.setText(error.toString());
}
});
// Add the request to the RequestQueue.
queue.add(stringRequest);
}
public void createPost(Context context, String url, JSONObject body) {
final TextView apiResultTextview = (TextView) ((Activity) context).findViewById(R.id.api_result_textview);
RequestQueue requestQueue = Volley.newRequestQueue(context);
final String mRequestBody = body.toString();
StringRequest stringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.i("LOG_RESPONSE", response);
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e("LOG_RESPONSE", error.toString());
}
}) {
#Override
public String getBodyContentType() {
return "application/json; charset=utf-8";
}
#Override
public byte[] getBody() throws AuthFailureError {
try {
return mRequestBody == null ? null : mRequestBody.getBytes("utf-8");
} catch (UnsupportedEncodingException uee) {
VolleyLog.wtf("Unsupported Encoding while trying to get the bytes of %s using %s", mRequestBody, "utf-8");
return null;
}
}
#Override
protected Response<String> parseNetworkResponse(NetworkResponse response) {
String responseString = "";
if (response != null) {
responseString = String.valueOf(response.statusCode);
apiResultTextview.setText("Response is: " + responseString);
}
return Response.success(responseString, HttpHeaderParser.parseCacheHeaders(response));
}
};
requestQueue.add(stringRequest);
}

I solved it by changing method for call to code below. Problem was probably in JsonObjectRequest vs StringRequest. That's why I was getting only response code string.
public void createCall(int type, String url, JSONObject data, final int callback) {
JsonObjectRequest jsonRequest = new JsonObjectRequest(type, url,data,
new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
Log.d("Response", response.toString());
try {
callback(response, callback);
} catch (Exception e){
Log.d("API callback error", e.getMessage());
}
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.d("Error response", error.toString());
}
}
);
queue.add(jsonRequest);
}

add this code in you onResponse() Method
JSONObject jsonObj = new JSONObject(response);
String response_value = jsonObj.getString("response");

Expression expected error on Volley requests

I am getting an error called expression expected inside the bracket in this line. Volley.newRequestQueue(MainActivity); . This class is on another activity other than my MainActivity. Here is the snippet of my code:
public void youFunctionForVolleyRequest(final ServerCallbackJava callback) {
RequestQueue queue = Volley.newRequestQueue(MainActivity);
String url = "https://maps.googleapis.com/maps/api/distancematrix/json?units=metric&origins=22.2913,113.947&destinations=WanChai&mode=driving&key="REMOVED";
JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.POST,
url, null, new Response.Listener<JSONObject>()
{
#Override
public void onResponse(JSONObject response) {
callback.onSuccess(response); // call call back function here
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
//VolleyLog.d("Volley error json object ", "Error: " + error.getMessage());
}
})
{
#Override
public String getBodyContentType ()
{
return "application/json";
}
};
// Adding request to request queue
queue.add(jsonObjReq);
}
}

As you have created a class inside a activity/fragment, while calling the class you must pass the context of the activity and same pass to this function and replace the RequestQueue queue = Volley.newRequestQueue(MainActivity); with RequestQueue queue = Volley.newRequestQueue(mContext); the declared context inside your class.

You can do it with the help of following code snippet :
public class Main2Activity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
Button button = (Button)findViewById(R.id.btn);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
request r = new request(Main2Activity.this);
r.youFunctionForVolleyRequest();
}
});
}
class request{
Context ctx;
public request(Context mContext) {
ctx = mContext;
}
public void youFunctionForVolleyRequest() {
RequestQueue queue = Volley.newRequestQueue(ctx);
String url = "https://maps.googleapis.com/maps/api/distancematrix/json?units=metric&origins=22.2913,113.947&destinations=WanChai&mode=driving&key=";
JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.POST,
url, null, new Response.Listener<JSONObject>()
{
#Override
public void onResponse(JSONObject response) {
// callback.onSuccess(response); // call call back function here
System.out.println("success");
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
//VolleyLog.d("Volley error json object ", "Error: " + error.getMessage());
System.out.println("failed");
}
})
{
#Override
public String getBodyContentType ()
{
return "application/json";
}
};
// Adding request to request queue
queue.add(jsonObjReq);
}
}
}

If your code in Activity.class:
RequestQueue queue = Volley.newRequestQueue(this);//or
RequestQueue queue = Volley.newRequestQueue(Activity.this);//or
RequestQueue queue = Volley.newRequestQueue(getApplicationContext());
If your code in Fragment.class:
RequestQueue queue = Volley.newRequestQueue(getContext());//or
RequestQueue queue = Volley.newRequestQueue(getApplicationContext());//or
RequestQueue queue = Volley.newRequestQueue(Fragment.this.getContext());//or
RequestQueue queue = Volley.newRequestQueue(Fragment.this.getApplicationContext());

make global variable in class VolleyRequests
Context context;
and initialize it on constructor
public VolleyRequests(Context mcontext) { this.context= mcontext; }
then use this
RequestQueue queue = Volley.newRequestQueue(context);
when you call it in MainActivity use :
VolleyRequests volleyrequests = new VolleyRequests (this);

Inside that new class constructor, pass the context so that you use it with volley.
public class ClassWithVolley{
private Context context;
public ClassWithVolley(Context context){
this.context = context;
}
// continue