1. Parsing JSON data from a RESTful Web Service. DONE.

2. Download file. DONE

Next steps: we need to use the SQLITE database. There, we are going to store
the index for every downloaded file. With the advertisement id retrieved from
the JSON RESTful response, we have a unique identifier for the downloaded ad.
We are going to use that id to find out if we have to download a file because
we do not have it on the mobile or we can skip the download because it was already
downloaded.

diff --git a/Android/Testing/Test3/src/de/android/test3/NextActivity.java b/Android/Testing/Test3/src/de/android/test3/NextActivity.java
index 2ccdc8d..283e488 100644 (file)
--- a/Android/Testing/Test3/src/de/android/test3/NextActivity.java
+++ b/Android/Testing/Test3/src/de/android/test3/NextActivity.java
@@ -1,12 +1,16 @@
 package de.android.test3;
 
 import java.io.BufferedReader;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
+import java.io.OutputStream;
 import java.io.UnsupportedEncodingException;
 import java.net.MalformedURLException;
 import java.net.URISyntaxException;
 import java.net.URL;
+import java.util.Random;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import org.apache.http.HttpResponse;
@@ -15,6 +19,7 @@ import org.apache.http.client.ClientProtocolException;
 import org.apache.http.client.methods.HttpGet;
 import org.json.JSONArray;
 import org.json.JSONException;
+import org.json.JSONObject;
 import org.json.JSONTokener;
 
 import android.app.Activity;
@@ -30,6 +35,7 @@ import android.webkit.CookieManager;
 import android.webkit.CookieSyncManager;
 
 public class NextActivity extends Activity {
+       private static final String TAG = "NextActivity";
        private String myCookie;
        
         /** Called when the activity is first created. */
@@ -101,8 +107,7 @@ public class NextActivity extends Activity {
                        //RESTful WebService
                        url = new URL(URLAuth);
                } catch (MalformedURLException e) {
-                       // TODO Auto-generated catch block
-                       e.printStackTrace();
+                       Log.e(TAG, "Error while creating a URL", e);
                }
                webServiceConnection = new MobieAdHttpClient(this.myCookie, url);
                exec.execute(webServiceConnection);
@@ -111,9 +116,12 @@ public class NextActivity extends Activity {
    
    private class MobieAdHttpClient implements Runnable 
    {
+          private static final String USERAGENT ="MobieAds/1.0";
+          private static final String VALIDCHARS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
           private final String cookie;
           private static final String TAG = "MobieAdHttpClient";
-          private AndroidHttpClient httpClient;
+          private final AndroidHttpClient httpClient = AndroidHttpClient.newInstance(USERAGENT);
+          private final Random random = new Random();
           private final URL url;
         
           public MobieAdHttpClient(final String cookie, final URL url) {
@@ -124,7 +132,7 @@ public class NextActivity extends Activity {
           @Override
           public void run()
           {
-                  final String USERAGENT ="MobieAds/1.0";
+                  
                   final HttpGet httpGet = new HttpGet();
                   HttpResponse httpResponse = null;
                   
@@ -134,7 +142,6 @@ public class NextActivity extends Activity {
                   } catch (URISyntaxException e) {
                           Log.e(TAG, "Error while creating URI from URL.", e);  
                   }
-                  this.httpClient = AndroidHttpClient.newInstance(USERAGENT);
                   try {
                           httpResponse = httpClient.execute(httpGet);  
                   } catch (ClientProtocolException e) {
@@ -145,8 +152,7 @@ public class NextActivity extends Activity {
                   
                   this.httpClient.close();
                        //It should not be null anyway this check is not harmful
-                       if (httpResponse != null)
-                       {
+                       if (httpResponse != null) {
                                switch (httpResponse.getStatusLine().getStatusCode()) {
                                        case HttpStatus.SC_OK:
                                                //OK
@@ -155,6 +161,7 @@ public class NextActivity extends Activity {
                                                                        new InputStreamReader(httpResponse.getEntity().getContent(), "UTF-8"));
                                                        StringBuilder builder = new StringBuilder();
                                                        String currentLine = null;
+                                                       
                                                        currentLine = reader.readLine();
                                                        while (currentLine != null) {
                                                                builder.append(currentLine).append("\n");
@@ -162,6 +169,10 @@ public class NextActivity extends Activity {
                                                        }
                                                        JSONTokener tokener = new JSONTokener(builder.toString());
                                                        JSONArray finalResult = new JSONArray(tokener);
+                                                       for (int i = 0; i < finalResult.length(); i++) {
+                                                               JSONObject objects = finalResult.getJSONObject(i);
+                                                               downloadAds((Integer) objects.get("id"), (String)objects.get("domain"), (String)objects.get("link"));
+                                                       }
                                                } catch (UnsupportedEncodingException e) {
                                                        Log.e(TAG, "Error while parsing the JSON response from the RESTful Web Service.", e);
                                                } catch (IllegalStateException e) {
@@ -184,5 +195,46 @@ public class NextActivity extends Activity {
                                }
                        }       
           }
+          
+          public void downloadAds(Integer id, String domain, String link) throws IOException {
+                  final HttpGet httpGet = new HttpGet();
+                  final String URLAd = "http://" + domain + "/" + link;
+                  HttpResponse httpResponse = null;
+                  URL url = null;
+                  final OutputStream outputStream = new FileOutputStream(generateName(this.random, 10));
+                  
+                  try {
+                          url = new URL(URLAd);
+                  } catch (MalformedURLException e) {
+                          Log.e(TAG, "Error while creating a URL", e);
+                  }  
+                  try {
+                          httpGet.setURI(url.toURI());   
+                  } catch (URISyntaxException e) {
+                          Log.e(TAG, "Error while creating URI from URL.", e);  
+                  }
+                  try {
+                          httpResponse = httpClient.execute(httpGet);  
+                  } catch (ClientProtocolException e) {
+                          Log.e(TAG, "Error while executing HTTP client connection.", e);
+                  } catch (IOException e) {
+                          Log.e(TAG, "Error while executing HTTP client connection.", e);
+                  }
+                  
+                  this.httpClient.close();
+                  
+                  if (httpResponse != null) {
+                          httpResponse.getEntity().writeTo(outputStream);
+                  }
+          }
+          
+          public String generateName (Random random, int length) {
+                  char[] chars = new char[length];
+              for (int i=0; i < length; i++)
+              {
+                   chars[i] = VALIDCHARS.charAt(random.nextInt(VALIDCHARS.length()));
+              }
+              return new String(chars);
+          }
        }
 }