Java：通过 TCP 发送/接收数据并从 UDP 接收图像

Question

我正在处理来自 C# 的代码，并且我试图在 Java 中转换它。 基本上，在第一步中，我通过 TCP 向 IP 摄像机发送和接收一些数据命令（已完成），在第二步中，我必须通过 UDP 接收图像。 问题出在第二步：从 UDP 接收图像。 我尝试了互联网上的每一个代码，但没有一个工作。

C#中的原始代码是这样的：

*C#中的服务器连接示例

    Socket _ServerUdp = null; 
    Socket _ServerTcpIp = null; 
    IPEndPoint _EndpointUdp = null; 
    TcpClient _ClientUdp; 
    /// <summary> 
    /// Connect the socket 
   /// <summary> 
    public bool Connect(string IpAddr) 
    { 
         if (!_VideoPortConnect(IpAddr, 8501)) 
                return false; 
        if (!_CommandPortConnect(IpAddr, 8500)) 
            return false; 
        return true; 
    } 
    /// <summary> 
    /// Udp Connect 
    /// </summary> 
    bool _VideoPortConnect(string IpAddr, int VideoPort) 
    { 
        try 
        { 
            _ServerUdp = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp); 
            _EndpointUdp = new IPEndPoint(IPAddress.Parse(IpAddr), VideoPort); 
            _ClientUdp = new TcpClient(); 
            _ClientUdp.Connect(_EndpointUdp); 
            return true; 
        } 
        catch { return false; } 
    } 

    /// <summary> 
    /// Tcp Ip Connect 
    /// </summary> 
    bool _CommandPortConnect(string IpAddr, int CommandPort) 
    { 
        _ServerTcpIp = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); 
        IPEndPoint _RemoteEndPoint = new IPEndPoint(IPAddress.Parse(IpAddr), CommandPort); 
        _ServerTcpIp.ReceiveTimeout = 5000; 
        _ServerTcpIp.SendTimeout = 5000; 
        try 
        { 
            _ServerTcpIp.Connect(_RemoteEndPoint); 
            return true; 
        } 
        catch { return false; } 
    *}* 

发送命令和接收图像示例 该命令将通过 TCP/IP 发送。

字节[]数据接收=新字节[20000]；

    /// <summary> 
    /// Send Command Bar Code Reader 
    /// </summary> 
    /// <returns></returns> 
    bool SendCommand() 
    { 
        byte[] _Send = new byte[3]; 
        _Send[0]= 20;    //CMD BAR CODE READER 
        _Send[1] = 2;    //EXT CMD GET DATA 
        _Send[2] = 2;    //SEND IMAGE 
        if (!SendEth(_Send, 3)) 
            return false; 
        int _Ndati = ReadEth(); 
        if (_Ndati == -1) 
            return false; 
        if (DataReceived[4] != 20) 
            return false; 
        GetImage(); 
    } 
    /// <summary> 
    /// Send Data 
    /// </summary> 
    /// <param name="_Val"></param> 
    /// <param name="_Len"></param> 
    bool SendEth(byte[] _Val, Int32 _Len) 
    { 
        try 
        { 
            byte[] _Send = new byte[_Len + 4]; 
            int _Value = _Len; 
            Array.Copy(_Val, 0, _Send, 4, _Len); 
            _Send[3] = (byte)_Value; 
            _Value <<= 8; 
            _Send[2] = (byte)_Value; 
            _Value <<= 8; 
            _Send[1] = (byte)_Value; 
            _Value <<= 8; 
            _Send[0] = (byte)_Value; 
            _ServerTcpIp.Send(_Send, _Len + 4, SocketFlags.None); 
        } 
        catch { return false; } 
        return true; 
    }
    /// <summary> 
    /// Read Data from Ethernet 
    /// </summary> 
    /// <param name="LenDati"></param> 
    /// <returns>array dati</returns> 
    internal int ReadEth() 
    { 
        int _Ndati; 
        try 
        { 
            _Ndati = _ServerTcpIp.Receive(DataReceived, SocketFlags.None); 
            DataPointer =0; 
            int _Len = GetInt(); 
            if(_Len!=_Ndati-4) 
            { 
                int _Diff = (_Ndati - 4) - _Len; 
                byte[] BuffRx = new byte[_Diff]; 
                int _NrDati = 0; 
                int _PuntRx = _Ndati; 
                while (_PuntRx < _Diff) 
                { 
                    _NrDati = _ServerTcpIp.Receive(BuffRx, _Diff, SocketFlags.None); 
                    for (int n = 0; n < _NrDati; n++) 
                        DataReceived[_PuntRx++] = BuffRx[n]; 
                } 
            } 
            return _Ndati; 
        } 

        catch { return -1; } 
    } 

    /// <summary> 
    /// Get Image 
    /// </summary> 
    /// <returns></returns> 
    internal ImageSource GetImage() 
    { 
        //get image 
        NetworkStream _Stream = _ClientUdp.GetStream(); 
        byte[] _Data = (byte[])_Formatter.Deserialize(_Stream); 
        MemoryStream _ImgStream = new MemoryStream(_Data); 
        ImageSource _Image = BitmapFrame.Create(_ImgStream, BitmapCreateOptions.None, 
        BitmapCacheOption.OnLoad); 
        return _Image; 
    } 

我的JAVA代码：

公共课 TFinale {

static byte[] DataReceived = new byte[20000];

public static void main(String[] args) throws Exception {
    String[] args8500 = new String[2];
    args8500[0] = "10.0.0.123";
    args8500[1] = "8500";
    int port8500 = Integer.parseInt(args8500[1]);

    String[] args8501 = new String[2];
    args8501[0] = "10.0.0.123";
    args8501[1] = "8501";
    int port8501 = Integer.parseInt(args8501[1]);

    Socket clientSocket8501 = TFinale.createSocket(args8501[0], port8501);
    if (clientSocket8501 == null) {
    System.err.println("Unable to create socket to " + args8501[0] + ":" + port8501 + ".");
    System.exit(1);
    }
    Socket clientSocket8500 = TFinale.createSocket(args8500[0], port8500);

    if (clientSocket8500 == null) {
        System.err.println("Unable to create socket to " + args8500[0] + ":" + port8500 + ".");
        System.exit(1);
    }

    byte[] _Send = new byte[3];
    _Send[0] = 22;    //CMD BAR CODE READER 
    _Send[1] = 2;    //EXT CMD GET DATA 
    _Send[2] = 2;    //SEND IMAGE
    int _Len1 = 3;
    byte[] SendEth1 = SendEth(_Send, _Len1);

    DataOutputStream serverOut = null;
    try {
        serverOut = new DataOutputStream(clientSocket8500.getOutputStream());
        serverOut.write(SendEth1, 0, 7);
        System.out.println("serverOut writed!");
    } catch (IOException ex) {
        Logger.getLogger(TFinale.class.getName()).log(Level.SEVERE, null, ex);
    }
    DataInputStream in = null;
    try {
        byte[] messageByte = new byte[1000];
        boolean end = false;
        String dataString = "";
        in = new DataInputStream(clientSocket8500.getInputStream());
        int bytesRead = 0;
        int f = 0;
        //System.out.println("Please type 8500 clientSocket......");
        for (f = 0; f < 7; f++) {
            messageByte[f] = in.readByte();
            System.out.println("messageByte 8500[" + f + "] " + messageByte[f]);
        }
        ByteBuffer byteBuffer = ByteBuffer.wrap(messageByte, 0, f);
        int bytesToRead = byteBuffer.getShort();
        System.out.println("About to read " + bytesToRead + " octets");
    } catch (IOException ex) {
        Logger.getLogger(TCPClient1.class.getName()).log(Level.SEVERE, null, ex);
    } finally {
        try {
            in.close();
        } catch (IOException ex) {
            Logger.getLogger(TCPClient1.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
    timeDelay(1000);
    try {
        serverOut.close();
        System.out.println("serverOut closed!");
        in.close();
        System.out.println("in closed!");
        clientSocket8501.close();
        System.out.println("clientSocket8501 closed!");
        clientSocket8500.close();
        System.out.println("clientSocket8500 closed!");
    } catch (IOException ex) {
        System.out.println("error:" + ex);
    }

}

private static Socket createSocket(final String hostname, final int port) {
    try {
        Socket clientSocket = new Socket(hostname, port);
        System.out.println(hostname + ":" + port + " socket created!");
        return clientSocket;
    } catch (UnknownHostException e) {
        System.err.println(" " + hostname + " cannot be resolved as a network host.");
        return null;
    } catch (IOException e) {
        System.err
                .println("An exception occurred while communicating with the TCPServer: "
                        + e.getMessage());
        e.printStackTrace();
        return null;
    }
}


private static void timeDelay(int i) {
    try {
        Thread.sleep(i);
    } catch (InterruptedException e) {
    }
}

private static byte[] SendEth(byte[] _Val, int _Len) {
    byte[] _Send = new byte[_Len + 4];
    int _Value = _Len;
    System.arraycopy(_Val, 0, _Send, 4, _Len);
    //Array.Copy(_Val, 0, _Send, 4, _Len); 
    _Send[3] = (byte) _Value;
    _Value <<= 8;
    _Send[2] = (byte) _Value;
    _Value <<= 8;
    _Send[1] = (byte) _Value;
    _Value <<= 8;
    _Send[0] = (byte) _Value;
    return _Send;

}

}

谢谢大家能帮我！

Answer 1

@Federico111，您应该使用java.net.DatagramSocket而不是Socket来处理 UDP。