Question

我正在创建一个从客户端发送文件的应用程序，并通过Socket通过服务器接收它。

当我在我的PC上测试应用程序（同一台PC上的客户端 - 服务器）时，一切运行正常，但是当我在不同的PC上测试应用程序时，我遇到了以下错误。

第一次尝试：没有任何事情发生，没有错误，没有发送文件。
第二次尝试：Java抛出了已经使用的Ip错误，但是我在服务器PC上收到了该文件但没有数据。

以下是客户的代码：

    public class FileSender {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
FileSender nioClient = new FileSender();
SocketChannel socketChannel = nioClient.createChannel();
try {
    nioClient.sendFile(socketChannel);
} catch (FileNotFoundException | InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
//SocketChannel socketChannel = nioClient.createc
    }
public SocketChannel createChannel(){

    SocketChannel socketChannel = null;

    try {
        socketChannel = SocketChannel.open();
        SocketAddress socketAddress = new InetSocketAddress("xx.xxx.xxx.x", 10002);
        socketChannel.connect(socketAddress);
        System.out.println("Connected..Now Sending the File");
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
return socketChannel;   
}

public void sendFile(SocketChannel socketChannel) throws FileNotFoundException, InterruptedException{

    RandomAccessFile afile = null;

    try {
        File file = new File("/home/dionisio/Imágenes/ImagenesOriginalesPrueba/flowers.jpg");
        afile = new RandomAccessFile(file, "r");
        FileChannel inChannel = afile.getChannel();
        ByteBuffer buffer = ByteBuffer.allocate(8192);
        while (inChannel.read(buffer) != -1) {
            buffer.flip();
            socketChannel.write(buffer);
            buffer.clear();     
        }
        socketChannel.close();
        afile.close();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

}

服务器代码

public class FileReceiver {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
FileReceiver nioServer = new FileReceiver();
SocketChannel socketChannel = nioServer.createServerSocketChannel();
nioServer.readFileFromSocket(socketChannel);
    }

    private SocketChannel createServerSocketChannel() {
        // TODO Auto-generated method stub
        ServerSocketChannel serverSocketChannel = null;
        SocketChannel socketChannel = null;

        try {
            serverSocketChannel = ServerSocketChannel.open();
            serverSocketChannel.socket().bind(new InetSocketAddress(10002));
            socketChannel = serverSocketChannel.accept();
            System.out.println("Connection Stablished..."+socketChannel.getRemoteAddress());

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return socketChannel;
    }


    private void readFileFromSocket(SocketChannel socketChannel) {
        // TODO Auto-generated method stub

    RandomAccessFile afile = null;

    try {
        afile = new RandomAccessFile("/home/dionisio/Imágenes/imagenesCopiaPrueba/flowersCopia.jpg","rw");
        ByteBuffer buffer = ByteBuffer.allocate(8192);
        FileChannel fileChannel = afile.getChannel();
        while (socketChannel.read(buffer)>0) {
            buffer.flip();
            fileChannel.write(buffer);
            buffer.clear();
        }
        Thread.sleep(1000);
        fileChannel.close();
        System.out.println("End of file reached...Closing Channel");
        socketChannel.close();
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }


    }


}

Answer 1

您的读取循环不正确。它们应该是以下形式：

while (in.read(buffer) > 0 || buffer.position() > 0)
{
    buffer.flip();
    out.write(buffer);
    buffer.compact();
}

否则您可能会丢失数据。

NB

Java不会抛出错误'IP已在使用中'。准确无误。
你不需要睡觉。不要为网络代码添加睡眠。它没有解决任何问题。

Answer 2

我的伙计感谢您的回复，现在我知道我的错误是什么，我在我的客户端应用程序上输入了错误的IP地址。

然而，EJP我会建议你在频道上写字时进行更好的字节检查。

Java套接字，接收空文件

2 个答案: