private void saveImage(String uri, String savePath) throws IOException {

     // 创建连接

     HttpURLConnection conn = createConnection(uri);

     // 拿到输入流,此流即是图片资源本身

     InputStream imputStream = conn.getInputStream();

     // 指使Bitmap通过流获取数据

     Bitmap bitmap = BitmapFactory.decodeStream(imputStream);

     File file = new File(savePath);

     OutputStream out = new BufferedOutputStream(new FileOutputStream(file.getCanonicalPath()), BUFFER_SIZE);

     // 指使Bitmap以相应的格式,将当前Bitmap中的图片数据保存到文件

     if (bitmap.compress(Bitmap.CompressFormat.PNG, 100, out)) {

         out.flush();

         out.close();

     }

 }

 private void saveImage(String uri, String savePath) throws IOException {

     // 创建连接

     HttpURLConnection conn = createConnection(uri);

     // 拿到输入流,此流即是图片资源本身

         InputStream imputStream = conn.getInputStream();

         // 将所有InputStream写到byte数组当中

         byte[] targetData = null;

         byte[] bytePart = new byte[4096];

         while (true) {

             int readLength = imputStream.read(bytePart);

             if (readLength == -1) {

                 break;

             } else {

                 byte[] temp = new byte[readLength + (targetData == null ? 0 : targetData.length)];

                 if (targetData != null) {

                     System.arraycopy(targetData, 0, temp, 0, targetData.length);

                     System.arraycopy(bytePart, 0, temp, targetData.length, readLength);

                 } else {

                     System.arraycopy(bytePart, 0, temp, 0, readLength);

                 }

                 targetData = temp;

             }

         }

         // 指使Bitmap通过byte数组获取数据

         Bitmap bitmap = BitmapFactory.decodeByteArray(targetData, 0, targetData.length);

     File file = new File(savePath);

     OutputStream out = new BufferedOutputStream(new FileOutputStream(file.getCanonicalPath()), BUFFER_SIZE);

     // 指使Bitmap以相应的格式,将当前Bitmap中的图片数据保存到文件

     if (bitmap.compress(Bitmap.CompressFormat.PNG, 100, out)) {

         out.flush();

         out.close();

     }

 }