Custom asynchronous HTTP client in Android
I use https://github.com/loopj/android-async-http but I think this can be applied to asynchronous tasks ( native tasks).
AsyncHttpClient client = new AsyncHttpClient();
client.get("http://www.google.com", new AsyncHttpResponseHandler() {
@Override
public void onStart() {
called before request is started
Some debugging code here
}
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] response) {
called when response HTTP status is "200 OK"
here is the interesting part
}
@Override
public void onFailure(int statusCode, Header[] headers, byte[] errorResponse, Throwable e) {
called when response HTTP status is "4XX" (eg. 401, 403, 404)
Some debugging code here, show retry dialog, feedback etc.
}
@Override
public void onRetry(int retryNo) {
Some debugging code here-------
}
});
I use it a lot in many separate classes. onStart, onFailure, onRetry are the same everywhere, just copy and paste, only onSuccess is different.
I
want to keep my code as clean as possible and reuse code I’ve already written, so my question is, how do I customize it in a separate “file” and then reuse it. I just need the “OnSuccess” function. Thanks
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Solutions for GET and POST (thanks to furkan3ayraktar).
The first file, RequestListener
package com.classicharmony.krakenmessages.utils.AsyncHttp;
import org.apache.http.Header;
public interface RequestListener {
public void onSuccess(int statusCode, Header[] headers, byte[] response);
}
The second file, RequestHandler
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.util.Log;
import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.AsyncHttpResponseHandler;
import org.apache.http.Header;
import org.apache.http.entity.StringEntity;
import java.io.UnsupportedEncodingException;
public class RequestHandler {
private static RequestHandler instance;
private AsyncHttpClient client;
private static final boolean SHOW_DEBUG_ALERT_DIALOG = true;
private RequestHandler() {
client = new AsyncHttpClient();
}
public static RequestHandler getInstance() {
if (instance == null) {
instance = new RequestHandler();
}
return instance;
}
public void make_get_Request(final Context context, final String url, final RequestListener listener) {
client.get(url, new AsyncHttpResponseHandler() {
@Override
public void onStart() {
Log.v("▒▒▒▒▒▒▒ GET ", url);
}
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] response) {
listener.onSuccess(statusCode, headers, response);
}
@Override
public void onFailure(int statusCode, Header[] headers, byte[] errorResponse, Throwable e) {
Log.e("▒▒▒▒▒▒▒ GET FAILED ", url);
Log.e("▒▒▒▒▒▒▒ GET FAILED ", e.getLocalizedMessage());
if (DUtils.isDebuggable(context) && SHOW_DEBUG_ALERT_DIALOG) {
AlertDialog.Builder builder = new AlertDialog.Builder(context);
builder.setTitle("▒▒▒▒▒ ERROR ▒▒▒▒▒");
String error_msg;
if (errorResponse != null) {
try {
error_msg = String.valueOf(new String(errorResponse, "UTF-8"));
} catch (UnsupportedEncodingException e1) {
error_msg = e.getLocalizedMessage();
}
} else {
error_msg = e.getLocalizedMessage();
}
builder.setMessage(context.getClass().getSimpleName() + " -> " + error_msg)
.setCancelable(true)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.dismiss();
}
});
AlertDialog alert = builder.create();
alert.show();
}
}
@Override
public void onRetry(int retryNo) {
Log.e("▒▒▒▒▒▒▒ RETRYING ", "....." + String.valueOf(retryNo));
}
});
}
public void make_post_Request(final Context context, final StringEntity entity, final String url, final RequestListener listener) {
client.post(context, url, entity, "application/json", new AsyncHttpResponseHandler() {
@Override
public void onStart() {
Log.v("▒▒▒▒▒▒▒ POST ", url);
}
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] response) {
listener.onSuccess(statusCode, headers, response);
}
@Override
public void onFailure(int statusCode, Header[] headers, byte[] errorResponse, Throwable e) {
Log.e("▒▒▒▒▒▒▒ POST FAILED ", url);
Log.e("▒▒▒▒▒▒▒ POST FAILED ", context.getClass().getSimpleName() + " -> " + e.getLocalizedMessage());
if (DUtils.isDebuggable(context) && SHOW_DEBUG_ALERT_DIALOG) {
AlertDialog.Builder builder = new AlertDialog.Builder(context);
builder.setTitle("▒▒▒▒▒ ERROR ▒▒▒▒▒");
String error_msg;
if (errorResponse != null) {
try {
error_msg = String.valueOf(new String(errorResponse, "UTF-8"));
} catch (UnsupportedEncodingException e1) {
error_msg = e.getLocalizedMessage();
}
} else {
error_msg = e.getLocalizedMessage();
}
builder.setMessage(context.getClass().getSimpleName() + " -> " + error_msg)
.setCancelable(true)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.dismiss();
}
});
AlertDialog alert = builder.create();
alert.show();
}
}
@Override
public void onRetry(int retryNo) {
Log.e("▒▒▒▒▒▒▒ RETRYING ", "....." + String.valueOf(retryNo));
}
});
}
}
The third “utility” for displaying or not displaying dialog boxes.
public static boolean isDebuggable(Context ctx) {
boolean debuggable = false;
X500Principal DEBUG_DN = new X500Principal("CN=Android Debug,O=Android,C=US");
try {
PackageInfo pinfo = ctx.getPackageManager().getPackageInfo(ctx.getPackageName(), PackageManager.GET_SIGNATURES);
Signature signatures[] = pinfo.signatures;
CertificateFactory cf = CertificateFactory.getInstance("X.509");
for (int i = 0; i < signatures.length; i++) {
ByteArrayInputStream stream = new ByteArrayInputStream(signatures[i].toByteArray());
X509Certificate cert = (X509Certificate) cf.generateCertificate(stream);
debuggable = cert.getSubjectX500Principal().equals(DEBUG_DN);
if (debuggable)
break;
}
} catch (PackageManager.NameNotFoundException e) {
debuggable variable will remain false
} catch (CertificateException e) {
debuggable variable will remain false
}
return debuggable;
}
Example of how to call it for POST:
JSONObject jsonParams = new JSONObject();
StringEntity entity;
try {
jsonParams.put("from_user_id", "dan");
jsonParams.put("to_user_id", "vili");
jsonParams.put("message", "hello world");
entity = new StringEntity(jsonParams.toString());
} catch (JSONException e) {
e.printStackTrace();
return;
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
return;
}
RequestHandler handler = RequestHandler.getInstance();
handler.make_post_Request(getActivity(), entity, "http://your_server/api/etc", new RequestListener() {
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] response) {
try {
String server_response = String.valueOf(new String(response, "UTF-8"));
Log.v("Server response",server_response);
} catch (UnsupportedEncodingException e1) {
}
}
});
Solution
You can create your own empty version of AsyncHttpResponseHandler
, which does not implement the onSuccess
method.
public abstract class OWADVLHttpResponseHandler extends AsyncHttpResponseHandler {
@Override
public void onStart() {}
@Override
public void onFailure(int statusCode, Header[] headers, byte[] errorResponse, Throwable e) {}
@Override
public void onRetry(int retryNo) {}
}
Your code will look like this:
AsyncHttpClient client = new AsyncHttpClient();
client.get("http://www.google.com", new OWADVLHttpResponseHandler() {
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] response) {
....
}
});
Obviously, you can fill in some things in the non-overriding methods in the base class.