see method in jsonObjectRequest post sending get code example

Example 1: jsonObjectRequest = new JsonObjectRequest( Request.Method.GET, url, ecplain

// http client instance
private DefaultHttpClient mHttpClient;
public RequestQueue getRequestQueue() {
    // lazy initialize the request queue, the queue instance will be
    // created when it is accessed for the first time
    if (mRequestQueue == null) {
        // Create an instance of the Http client. 
        // We need this in order to access the cookie store
        mHttpClient = new DefaultHttpClient();
        // create the request queue
        mRequestQueue = Volley.newRequestQueue(this, new HttpClientStack(mHttpClient));
    }
    return mRequestQueue;
}

/**
 * Method to set a cookie
 */
public void setCookie() {
    CookieStore cs = mHttpClient.getCookieStore();
    // create a cookie
    cs.addCookie(new BasicClientCookie2("cookie", "spooky"));
}


// add the cookie before adding the request to the queue
setCookie();

// add the request to the queue
mRequestQueue.add(request);

Example 2: jsonObjectRequest = new JsonObjectRequest( Request.Method.GET, url, ecplain

JsonObjectRequest req = new JsonObjectRequest(URL, new JSONObject(params),
           new Response.Listener<JSONObject>() {
               @Override
               public void onResponse(JSONObject response) {
                   // handle response
               }
           }, new Response.ErrorListener() {
               @Override
               public void onErrorResponse(VolleyError error) {
                   // handle error                        
               }
           }) {

       @Override
       public Map<String, String> getHeaders() throws AuthFailureError {
           HashMap<String, String> headers = new HashMap<String, String>();
           headers.put("CUSTOM_HEADER", "Yahoo");
           headers.put("ANOTHER_CUSTOM_HEADER", "Google");
           return headers;
       }
   };