Retry request onErrorResponse Android volley - request

Question

When i receive an error in onerrorrepsonse of android volley request i want to retry the request. How can i achieve this?

Answer 1

well, you can create the RetryPolicy to change default retry behavior, only specify timeout milliseconds, retry count arguments :
public class YourRequest extends StringRequest {
public YourRequest(String url, Response.Listener<String> listener,
Response.ErrorListener errorListener) {
super(url, listener, errorListener);
setRetryPolicy(new DefaultRetryPolicy(DefaultRetryPolicy.DEFAULT_TIMEOUT_MS,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
}
}
the another way is estimate the VolleyError, re-execute the same request again when if was TimeoutError instance :
public static void executeRequest() {
RequestQueue.add(new YourRequest("http://your.url.com/", new Response.Listener<String>() {
#Override
public void onResponse(String response) {
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
if (error instanceof TimeoutError) {
// note : may cause recursive invoke if always timeout.
executeRequest();
}
}
}));
}
you may have a question at this very moment : "have Volley offer some retry callback methods ?", the answer is "none". but there have a project calls Netroid which based Volley and satisfy preceded question, with it, you can take a retry callback if you care about that, you can calculate how much time used when retry coming and how long this request execute, the code style like this :
final String REQUESTS_TAG = "Request-Demo";
String url = "http://facebook.com/";
JsonObjectRequest request = new JsonObjectRequest(url, null, new Listener<JSONObject>() {
long startTimeMs;
int retryCount;
#Override
public void onPreExecute() {
startTimeMs = SystemClock.elapsedRealtime();
}
#Override
public void onFinish() {
RequestQueue.add(request);
NetroidLog.e(REQUESTS_TAG);
}
#Override
public void onRetry() {
long executedTime = SystemClock.elapsedRealtime() - startTimeMs;
if (++retryCount > 5 || executedTime > 30000) {
NetroidLog.e("retryCount : " + retryCount + " executedTime : " + executedTime);
mQueue.cancelAll(REQUESTS_TAG);
} else {
NetroidLog.e(REQUESTS_TAG);
}
}
});
request.setRetryPolicy(new DefaultRetryPolicy(5000, 20, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
request.setTag(REQUESTS_TAG);
RequestQueue.add(request);
Netroid also have many other handy and powerful features, hope that will help you enough :).

Answer 2

You can set counter variable for trying specific time with out making it full recursive
static int count=10; //so its will try ten time
public void userLogin(final View view)
{
final RequestQueue requestQueue= Volley.newRequestQueue(getApplicationContext());
String url = "http://192.168.43.107/mobodb/register.php";
StringRequest stringRequest=new StringRequest(Request.Method.POST,url,new Response.Listener<String>()
{
#Override
public void onResponse(String response) {
Toast.makeText(getApplicationContext(),"Updated",Toast.LENGTH_LONG).show();
}
}
},new Response.ErrorListener()
{
#Override
public void onErrorResponse(VolleyError error) {
count=count-1;
Toast.makeText(getApplicationContext(),"Retry left"+count,Toast.LENGTH_LONG).show();
if (count>0) {
// note : may cause recursive invoke if always timeout.
userLogin(view);
}
else
{
Toast.makeText(getApplicationContext(),"Request failed pls check network connection or the error is "+error.getMessage(),Toast.LENGTH_LONG).show();
}
}
})
{
#Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String,String> paramter=new HashMap<String,String>();
paramter.put("name",login_name);
paramter.put("user_pass",login_pass);
return paramter;
}
};
requestQueue.add(stringRequest);
stringRequest.setRetryPolicy(new DefaultRetryPolicy(20 * 1000, 10, 1.0f));
you can also check response inside which you can return from php and deal in your java class
#Override
public void onResponse(String response) {
if(response.contains("no record found for"))
Toast.makeText(getApplicationContext(),response.toString(),Toast.LENGTH_LONG).show();
else
{
Toast.makeText(getApplicationContext(),"Updated num of row is"+response.toString(),Toast.LENGTH_LONG).show();
}
}
your PHP code will be
if($res){
$resp=mysql_affected_rows();
if($resp==0)
{
$resp="no record found for".$_POST['name'];
}
if($resp==1 or $resp>1)
{
$resp=mysql_affected_rows();
}else $resp="efrror is".mysql_error();