I am thinking of implementing the Android Volley library in my next projects (Google IO presentation about Volley).
However, I haven't found any serious API for that library.
How do I upload files, do POST/GET requests, and add a Gson parser as a JSON parser using Volley?
Edit: finally here it is an official training about "Volley library"
I found some examples about Volley library
one good simple example by Paresh Mayani
other example by Hardik Trivedi
(NEW) Android working with Volley Library by Ravi Tamada
Unfortunately there is no documentation for a Volley library like JavaDocs until now. Only repo on github and several tutorials across the Internet. So the only good docs is source code :) . When I played with Volley I read this tutorial.
About post/get you can read this : Volley - POST/GET parameters
Hope this helps
This is an illustration for making a POST request using Volley. StringRequest is used to get response in the form of String.
Assuming your rest API returns a JSON. The JSON response from your API is received as String here, which you can covert again to JSON and process it further. Added comments in code.
StringRequest postRequest = new StringRequest(Request.Method.POST, "PUT_YOUR_REST_API_URL_HERE",
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
try {
final JSONObject jsonObject = new JSONObject(response);
// Process your json here as required
} catch (JSONException e) {
// Handle json exception as needed
}
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
String json = null;
NetworkResponse response = error.networkResponse;
if(response != null && response.data != null){
switch(response.statusCode) {
default:
String value = null;
try {
// It is important to put UTF-8 to receive proper data else you will get byte[] parsing error.
value = new String(response.data, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
json = trimMessage(value, "message");
// Use it for displaying error message to user
break;
}
}
loginError(json);
progressDialog.dismiss();
error.printStackTrace();
}
public String trimMessage(String json, String key){
String trimmedString = null;
try{
JSONObject obj = new JSONObject(json);
trimmedString = obj.getString(key);
} catch(JSONException e){
e.printStackTrace();
return null;
}
return trimmedString;
}
}
) {
@Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<>();
params.put("abc", "pass abc");
params.put("xyz", "pass xyz");
// Pass more params as needed in your rest API
// Example you may want to pass user input from EditText as a parameter
// editText.getText().toString().trim()
return params;
}
@Override
public String getBodyContentType() {
// This is where you specify the content type
return "application/x-www-form-urlencoded; charset=UTF-8";
}
};
// This adds the request to the request queue
MySingleton.getInstance(YourActivity.this)
.addToRequestQueue(postRequest);
// Below is MySingleton class
public class MySingleton {
private static MySingleton mInstance;
private RequestQueue mRequestQueue;
private static Context mCtx;
private MySingleton(Context context) {
mCtx = context;
mRequestQueue = getRequestQueue();
}
public static synchronized MySingleton getInstance(Context context) {
if (mInstance == null) {
mInstance = new MySingleton(context);
}
return mInstance;
}
public RequestQueue getRequestQueue() {
if (mRequestQueue == null) {
// getApplicationContext() is key, it keeps you from leaking the
// Activity or BroadcastReceiver if someone passes one in.
mRequestQueue = Volley.newRequestQueue(mCtx.getApplicationContext());
}
return mRequestQueue;
}
public <T> void addToRequestQueue(Request<T> req) {
getRequestQueue().add(req);
}
}
Just add volley.jar library to your project. and then
As per Android documentation :
// Instantiate the RequestQueue.
RequestQueue queue = Volley.newRequestQueue(this);
String url ="http://www.google.com";
// 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) {
// process your response here
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
//perform operation here after getting error
}
});
// Add the request to the RequestQueue.
queue.add(stringRequest);
For more help refer How to user Volley
Use this class. It provides you an easy way to connect to the database.
public class WebRequest {
private Context mContext;
private String mUrl;
private int mMethod;
private VolleyListener mVolleyListener;
public WebRequest(Context context) {
mContext = context;
}
public WebRequest setURL(String url) {
mUrl = url;
return this;
}
public WebRequest setMethod(int method) {
mMethod = method;
return this;
}
public WebRequest readFromURL() {
RequestQueue requestQueue = Volley.newRequestQueue(mContext);
StringRequest stringRequest = new StringRequest(mMethod, mUrl, new Response.Listener<String>() {
@Override
public void onResponse(String s) {
mVolleyListener.onRecieve(s);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError volleyError) {
mVolleyListener.onFail(volleyError);
}
});
requestQueue.add(stringRequest);
return this;
}
public WebRequest onListener(VolleyListener volleyListener) {
mVolleyListener = volleyListener;
return this;
}
public interface VolleyListener {
public void onRecieve(String data);
public void onFail(VolleyError volleyError);
}
}
Example usage:
new WebRequest(mContext)
.setURL("http://google.com")
.setMethod(Request.Method.POST)
.readFromURL()
.onListener(new WebRequest.VolleyListener() {
@Override
public void onRecieve(String data) {
}
@Override
public void onFail(VolleyError volleyError) {
}
});
In simple way
private void load() {
JsonArrayRequest arrayreq = new JsonArrayRequest(ip.ip+"loadcollege.php",
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
Album a;
try {
JSONArray data = new JSONArray(response.toString());
for (int i = 0; i < data.length(); i++) {
JSONObject c = data.getJSONObject(i);
one = c.getString("cname").split(",");
two=c.getString("caddress").split(",");
three = c.getString("image").split(",");
four = c.getString("cid").split(",");
five = c.getString("logo").split(",");
a = new Album(one[0].toString(),two[0].toString(),ip.ip+"images/"+ three[0].toString(),four[0].toString(),ip.ip+"images/"+ five[0].toString());
albumList.add(a);
}
adapter.notifyDataSetChanged();
} catch (JSONException e) {
e.printStackTrace();
}
}
},
// The final parameter overrides the method onErrorResponse() and passes VolleyError
//as a parameter
new Response.ErrorListener() {
@Override
// Handles errors that occur due to Volley
public void onErrorResponse(VolleyError error) {
Log.e("Volley", "Error");
}
}
);
// Adds the JSON array request "arrayreq" to the request queue
requestQueue.add(arrayreq);
}
Before testing all of the above answers, include
compile 'com.android.volley:volley:1.0.0'
in your gradle file and don't forgot to add the Internet permission to your Manifest file.
private void userregister() {
final ProgressDialog pDialog = new ProgressDialog(this);
pDialog.setMessage("Loading...");
pDialog.show();
RequestQueue queue = Volley.newRequestQueue(SignupActivity.this);
String url = "you";
StringRequest stringRequest = new StringRequest(Request.Method.POST, url,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
pDialog.cancel();
try {
JSONObject jsonObject= new JSONObject(response.toString());
Log.e("status", ""+jsonObject.getString("status"));
if(jsonObject.getString("status").equals("success"))
{
String studentid=jsonObject.getString("id");
Intent intent=new Intent(SignupActivity.this, OTPVerificationActivity.class);
startActivity(intent);
finish();
}
} catch (JSONException e) {
e.printStackTrace();
}
Log.e("String ", ""+response);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
}) {
@Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String, String> params = new HashMap<>();
params.put("password", input_password.getText().toString());
params.put("cpassword", input_reEnterPassword.getText().toString());
params.put("email", input_email.getText().toString());
params.put("status", "1");
params.put("last_name", input_lastname.getText().toString());
params.put("phone", input_mobile.getText().toString());
params.put("standard", input_reStandard.getText().toString());
params.put("first_name", input_name.getText().toString());
params.put("refcode", input_reReferal.getText().toString());
params.put("created_at","");
params.put("update_at", "");
params.put("address", input_address.getText().toString());
return params;
}
};
// Add the request to the RequestQueue.
queue.add(stringRequest);
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