Added option to append downloaded data to File if it already exists

Author: smarek

library/src/main/java/com/loopj/android/http/FileAsyncHttpResponseHandler.java

@@ -32,6 +32,7 @@
 public abstract class FileAsyncHttpResponseHandler extends AsyncHttpResponseHandler {
 
     protected final File mFile;
+    protected final boolean append;
     private static final String LOG_TAG = "FileAsyncHttpResponseHandler";
 
     /**
@@ -40,9 +41,20 @@ public abstract class FileAsyncHttpResponseHandler extends AsyncHttpResponseHand
      * @param file File to store response within, must not be null
      */
     public FileAsyncHttpResponseHandler(File file) {
+        this(file, false);
+    }
+
+    /**
+     * Obtains new FileAsyncHttpResponseHandler and stores response in passed file
+     *
+     * @param file   File to store response within, must not be null
+     * @param append whether data should be appended to existing file
+     */
+    public FileAsyncHttpResponseHandler(File file, boolean append) {
         super();
         AssertUtils.asserts(file != null, "File passed into FileAsyncHttpResponseHandler constructor must not be null");
         this.mFile = file;
+        this.append = append;
     }
 
     /**
@@ -53,6 +65,7 @@ public FileAsyncHttpResponseHandler(File file) {
     public FileAsyncHttpResponseHandler(Context context) {
         super();
         this.mFile = getTemporaryFile(context);
+        this.append = false;
     }
 
     /**
@@ -127,7 +140,7 @@ protected byte[] getResponseData(HttpEntity entity) throws IOException {
         if (entity != null) {
             InputStream instream = entity.getContent();
             long contentLength = entity.getContentLength();
-            FileOutputStream buffer = new FileOutputStream(getTargetFile());
+            FileOutputStream buffer = new FileOutputStream(getTargetFile(), this.append);
             if (instream != null) {
                 try {
                     byte[] tmp = new byte[BUFFER_SIZE];