Add implementation of Android ASCII reade and write

Author: wkh237

src/android/src/main/java/com/RNFetchBlob/RNFetchBlob.java

@@ -54,6 +54,16 @@ public void createFile(String path, String content, String encode, Callback call
         RNFetchBlobFS.createFile(path, content, encode, callback);
     }
 
+    @ReactMethod
+    public void createFileASCII(String path, ReadableArray dataArray, Callback callback) {
+        RNFetchBlobFS.createFileASCII(path, dataArray, callback);
+    }
+
+    @ReactMethod
+    public void writeArrayChunk(String streamId, ReadableArray dataArray, Callback callback) {
+        RNFetchBlobFS.writeArrayChunk(streamId, dataArray, callback);
+    }
+
     @ReactMethod
     public void unlink(String path, Callback callback) {
         RNFetchBlobFS.unlink(path, callback);

src/android/src/main/java/com/RNFetchBlob/RNFetchBlobFS.java

@@ -103,7 +103,14 @@ protected Integer doInBackground(String ... args) {
                         }
                     } else if (encoding.equalsIgnoreCase("ascii")) {
                         while ((cursor = fs.read(buffer)) != -1) {
-                            String chunk = EncodingUtils.getAsciiString(buffer, 0, cursor);
+                            String chunk = "[";
+                            for(int i =0;i<cursor;i++)
+                            {
+                                chunk += (int)buffer[i];
+                                if(i+1 < cursor)
+                                    chunk += ",";
+                            }
+                            chunk = chunk + "]";
                             emitStreamEvent(eventName, "data", chunk);
                         }
                     } else if (encoding.equalsIgnoreCase("base64")) {
@@ -127,7 +134,7 @@ protected Integer doInBackground(String ... args) {
                     if(!error)
                         emitStreamEvent(eventName, "end", "");
                     fs.close();
-
+                    buffer = null;
 
                 } catch (Exception err) {
                     emitStreamEvent(eventName, "error", err.getLocalizedMessage());
@@ -180,6 +187,30 @@ static void writeChunk(String streamId, String data, Callback callback) {
         try {
             stream.write(chunk);
             callback.invoke();
+            chunk = null;
+        } catch (Exception e) {
+            callback.invoke(e.getLocalizedMessage());
+        }
+    }
+
+    /**
+     * Write data using ascii array
+     * @param streamId File stream ID
+     * @param data  Data chunk in ascii array format
+     * @param callback JS context callback
+     */
+    static void writeArrayChunk(String streamId, ReadableArray data, Callback callback) {
+
+        RNFetchBlobFS fs = fileStreams.get(streamId);
+        OutputStream stream = fs.writeStreamInstance;
+        byte [] chunk = new byte[data.size()];
+        for(int i =0; i< data.size();i++) {
+            chunk[i] = (byte) data.getInt(i);
+        }
+        try {
+            stream.write(chunk);
+            callback.invoke();
+            chunk = null;
         } catch (Exception e) {
             callback.invoke(e.getLocalizedMessage());
         }
@@ -343,6 +374,27 @@ static void createFile(String path, String data, String encoding, Callback callb
         }
     }
 
+    static void createFileASCII(String path, ReadableArray data, Callback callback) {
+        try {
+            File dest = new File(path);
+            boolean created = dest.createNewFile();
+            if(!created) {
+                callback.invoke("failed to create file at path `" + path + "` for its parent path may not exists");
+                return;
+            }
+            OutputStream ostream = new FileOutputStream(dest);
+            byte [] chunk = new byte[data.size()];
+            for(int i =0; i<data.size();i++) {
+                chunk[i] = (byte) data.getInt(i);
+            }
+            ostream.write(chunk);
+            chunk = null;
+            callback.invoke(null, path);
+        } catch(Exception err) {
+            callback.invoke(err.getLocalizedMessage());
+        }
+    }
+
     static void removeSession(ReadableArray paths, Callback callback) {
 
         AsyncTask<ReadableArray, Integer, Integer> task = new AsyncTask<ReadableArray, Integer, Integer>() {