first version of http request retry system

Author: sbezboro

src/main/java/com/rollbar/android/http/HttpRequest.java

@@ -24,13 +24,17 @@ public class HttpRequest implements Runnable {
 
     private String method;
     private byte[] body;
+    
+    private int attempt;
 
     public HttpRequest(URL url, String method, HttpResponseHandler handler) {
         this.url = url;
         this.method = method;
         this.handler = handler;
 
         this.requestProperties = new HashMap<String, String>();
+        
+        attempt = 1;
     }
 
     public void setMethod(String method) {
@@ -54,7 +58,7 @@ public void run() {
         try {
             connection = (HttpURLConnection) url.openConnection();
         } catch (IOException e) {
-            handler.onFailure(new HttpResponse(e.toString()));
+            onFailure(new HttpResponse(e.toString()));
             return;
         }
 
@@ -88,14 +92,28 @@ public void run() {
             if (responseCode == 200) {
                 handler.onSuccess(response);
             } else {
-                handler.onFailure(response);
+                onFailure(response);
             }
         } catch (IOException e) {
-            handler.onFailure(new HttpResponse(e.toString()));
+            onFailure(new HttpResponse(e.toString()));
         } finally {
             connection.disconnect();
         }
     }
+    
+    private void onFailure(HttpResponse response) {
+        if (attempt < HttpRequestManager.MAX_RETRIES) {
+            attempt++;
+            
+            HttpRequestManager.getInstance().retryRequest(this);
+        } else {
+            handler.onFailure(response);
+        }
+    }
+    
+    public int getAttempt() {
+        return attempt;
+    }
 
     private String getResponseText(InputStream in) throws IOException {
         byte[] contents = new byte[1024];

src/main/java/com/rollbar/android/http/HttpRequestManager.java

@@ -3,16 +3,22 @@
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
 
 import org.json.JSONObject;
 
 public class HttpRequestManager {
+    public static final int MAX_RETRIES = 5;
+    
     private static HttpRequestManager instance = null;
     private ThreadPoolExecutor executor;
+    private ScheduledExecutorService service;
 
     private HttpRequestManager() {
         executor = (ThreadPoolExecutor) Executors.newCachedThreadPool();
+        service = Executors.newSingleThreadScheduledExecutor();
     }
 
     public static HttpRequestManager getInstance() {
@@ -41,4 +47,16 @@ public void postJson(String urlString, JSONObject json, HttpResponseHandler hand
 
         executor.execute(request);
     }
+    
+    public void retryRequest(final HttpRequest request) {
+        int retryDelay = request.getAttempt();
+        
+        service.schedule(new Runnable() {
+            
+            @Override
+            public void run() {
+                executor.execute(request);
+            }
+        }, retryDelay, TimeUnit.SECONDS);
+    }
 }