Android的TCP和UDP传输 简单程序

TCP UDP时常用的网络通信方式，具体内容及传输方式可以百度搜索这里不再赘述，

我做的主要是把源码发出来，给大家参考。

首先，TCP建立连接之后，通信双方都同时可以进行数据的传输，其次，他是全双工的；在保证可靠性上，采用超时重传和捎带确认机制。

常用的tcp连接图

服务器端代码

    try {  
                Boolean endFlag = false;  
                ServerSocket ss = new ServerSocket(12345);  
                while (!endFlag) {  
                    // 等待客户端连接  
                    Socket s = ss.accept();  
                    BufferedReader input = new BufferedReader(newInputStreamReader(s.getInputStream()));  
                    //注意第二个参数据为true将会自动flush，否则需要需要手动操作output.flush()  
                    PrintWriter output = newPrintWriter(s.getOutputStream(),true);  
                    String message = input.readLine();  
                    Log.d("Tcp Demo", "message from Client:"+message);  
                    output.println("message received!");  
                    //output.flush();  
                    if("shutDown".equals(message)){  
                        endFlag=true;  
                    }  
                    s.close();  
                }  
                ss.close();  
       
            } catch (UnknownHostException e) {  
                e.printStackTrace();  
            } catch (IOException e) {  
                e.printStackTrace();  
            } 

    try {  
                Socket s = new Socket("localhost", 12345);  
                // outgoing stream redirect to socket  
                OutputStream out = s.getOutputStream();  
                // 注意第二个参数据为true将会自动flush，否则需要需要手动操作out.flush()  
                PrintWriter output = new PrintWriter(out, true);  
                output.println("Hello IdeasAndroid!");  
                BufferedReader input = new BufferedReader(newInputStreamReader(s  
                        .getInputStream()));  
                // read line(s)  
                String message = input.readLine();  
                Log.d("Tcp Demo", "message From Server:" + message);  
                s.close();  
       
            } catch (UnknownHostException e) {  
                e.printStackTrace();  
            } catch (IOException e) {  
                e.printStackTrace();  
            } 

UDP服务器端代码：

    // UDP服务器监听的端口  
            Integer port = 12345;  
            // 接收的字节大小，客户端发送的数据不能超过这个大小  
            byte[] message = new byte[1024];  
            try {  
                // 建立Socket连接  
                DatagramSocket datagramSocket = new DatagramSocket(port);  
                DatagramPacket datagramPacket = new DatagramPacket(message,  
                        message.length);  
                try {  
                    while (true) {  
                        // 准备接收数据  
                        datagramSocket.receive(datagramPacket);  
                        Log.d("UDP Demo", datagramPacket.getAddress()  
                                .getHostAddress().toString()  
                                + ":" + new String(datagramPacket.getData()));  
                    }  
                } catch (IOException e) {  
                    e.printStackTrace();  
                }  
            } catch (SocketException e) {  
                e.printStackTrace();  
            } 

    public static void send(String message) {  
            message = (message == null ? "Hello IdeasAndroid!" : message);  
            int server_port = 12345;  
            DatagramSocket s = null;  
            try {  
                s = new DatagramSocket();  
            } catch (SocketException e) {  
                e.printStackTrace();  
            }  
            InetAddress local = null;  
            try {  
                // 换成服务器端IP  
                local = InetAddress.getByName("localhost");  
            } catch (UnknownHostException e) {  
                e.printStackTrace();  
            }  
            int msg_length = message.length();  
            byte[] messagemessageByte = message.getBytes();  
            DatagramPacket p = new DatagramPacket(messageByte, msg_length, local,  
                    server_port);  
            try {  
                s.send(p);  
            } catch (IOException e) {  
                e.printStackTrace();  
            }  
        }