java - 在套接字上发送和接收文件

Question

我正在从 java 服务器发送文件到远程 Android 客户端。我使用输出流写入字节。在读取这些字节时，read() 方法在流结束后继续尝试读取字节。如果我关闭服务器端的outputstream，则读取操作会正常工作。但我必须再次在同一个套接字上写入文件，因此无法关闭输出流任何解决方案？

注意:我的代码可以很好地共享单个文件

写入文件的代码

public static void writefile(String IP, String filepath, int port, OutputStream out) throws IOException {
    ByteFileConversion bfc = new ByteFileConversion();
    byte[] file = bfc.FileToByteConversion(filepath);

    out.write(file, 0, file.length);
    out.close(); // i donot want to close this and how can I tell reading side that stream is ended.
    System.out.println("WRITTEN");
}

我在 Android 上读取文件:

public Bitmap fileReceived(InputStream is) {

    Bitmap bitmap = null;
    String baseDir = Environment.getExternalStorageDirectory().getAbsolutePath();
    String fileName = "a.png";
    String imageInSD = baseDir + File.separator + fileName;
    //  System.out.println(imageInSD);
    if (is != null) {
        FileOutputStream fos = null;
        OutputStream bos = null;
        try {

            bos = new FileOutputStream(imageInSD);

            byte[] aByte = new byte[1024];
            int bytesRead;
            int index = 0;
            DataInputStream dis = new DataInputStream(is);


            while ((bytesRead = is.read(aByte)) > 0) {
                index = bytesRead + index;
                bos.write(aByte, 0, bytesRead);

                //  index = index+ bytesRead;

                System.out.println("Loop" + aByte + "    byte read are " + bytesRead + "whree  index =" + index);

            }
            bos.flush();
            bos.close();

            Log.i("IMSERVICE", "out of loop");
            java.io.FileInputStream in = new FileInputStream(imageInSD);
            bitmap = BitmapFactory.decodeStream(in);
            bitmap = BitmapFactory.decodeFile(imageInSD);

            Log.i("IMSERVICE", "saved");
            //  if (bitmap != null) 
            //       System.out.println("bitmap is    "+ bitmap.toString());

        } catch (IOException ex) {
            // Do exception handling      
            //      Log.i("IMSERVICE", "exception ");
            System.out.println("ex");
        }
    }

    return bitmap;
}

实际上，我想重置socket连接

提前致谢

Answer 1

您需要:

1. 在文件之前发送文件的长度。您可以为此使用 DataOutputStream.writeLong() ，并在接收器处使用 DataInputStream.readLong() 。

2. 从接收器的流中准确读取那么多字节:

   while (total < length && (count = in.read(buffer, 0, length-total > buffer.length ? buffer.length : (int)(length-total))) > 0)
   {
       out.write(buffer, 0, count);
       total += count;
   }
   

E&OE

Actually I want to reset socket connection

实际上你不想做这样的事情。