Java——通信协议

不念不忘少年蓝@ 2022-05-12 09:42 185阅读 0赞

# 一、基于socket通信——TCP #

客户端输入一个hello，服务端进行输出  
这个传输过程就是先建立一个会话，然后有一个流，基于TCP的套接字完成

//基于socket通信的服务端
    public class ServerSocket_Server {
        public static void main(String[] args) throws IOException {
            //
            ServerSocket serverSocket=null;
            //
            BufferedReader bufferedReader=null;
            try {
                //打开一个服务 8080端口
               serverSocket=new ServerSocket(8080);
               //接收一个客户端连接，等的客户端连接
                //socket中基于流作为传输
                Socket socket=serverSocket.accept();
                //获得输入流
                bufferedReader=new BufferedReader(new InputStreamReader(socket.getInputStream()));
                System.out.println(bufferedReader.readLine());//输出
    
            }catch (IOException e){
                e.printStackTrace();
            }finally {
                if(bufferedReader!=null){
                    bufferedReader.close();
                }
                if(serverSocket!=null){
                    serverSocket.close();
                }
    
            }
    
        }
    }
    
    
    
    //客户端
    public class ServerSocket_Client {
        public static void main(String[] args) throws IOException {
            Socket socket=null;
            try {
                //用socket建立连接
                socket=new Socket("127.0.0.1",8080);
                //传输
                PrintWriter out=new PrintWriter(socket.getOutputStream(),true);
                out.println("hello");
            }catch (Exception e){
                e.printStackTrace();
            }finally {
                if(socket!=null){
                    socket.close();
                }
            }
        }
    }

# 二、基于DatagramSocket的通信——UDP #

public class UDPServerDemo {
        public static void main(String[] args) throws IOException {
            DatagramSocket datagramSocket=null;
           try {
               //创建服务，并且接收一个数据包
               datagramSocket=new DatagramSocket(8080);
               byte[] receiveData=new byte[1024];
               //接收数据的数据包
               DatagramPacket receivePacket=new DatagramPacket(receiveData,receiveData.length);
               datagramSocket.receive(receivePacket);
               //收到数据之后输出来
               System.out.println(new String(receiveData,0,receivePacket.getLength()));
           }finally {
               if(datagramSocket!=null){
                   datagramSocket.close();
               }
           }
        }
    }
    
    
    
    public class UDPClientDemo {
    
        public static void main(String[] args) throws IOException {
            DatagramSocket datagramSocket=new DatagramSocket();
            try {
                //获得地址信息
                InetAddress address=InetAddress.getByName("localhost");
                byte[] sendData="Hello,whm".getBytes();
                //要发送的数据包
                DatagramPacket sendPacket=new DatagramPacket(sendData,sendData.length,address,8080);
                //发送
                datagramSocket.send(sendPacket);
            }catch (IOException e){
                e.printStackTrace();
            }finally {
                if(datagramSocket!=null){
                    datagramSocket.close();
                }
            }
        }
    
    }

# 三、双向通信——全双工 #

public class DoubleSocketServer {
    
        public static void main(String[] args) throws IOException {
            ServerSocket serverSocket=null;
    
            try {
                serverSocket=new ServerSocket(8080);//监听端口号
                //等待客户端连接
                Socket socket=serverSocket.accept();
    
                //通过BufferedReader拿到客户端输入流
                BufferedReader is=new BufferedReader(new InputStreamReader(socket.getInputStream()));
                //输出流
                PrintWriter os=new PrintWriter(socket.getOutputStream());
                //通过控制台信息作为坐蓐
                BufferedReader sin=new BufferedReader(new InputStreamReader(System.in));
                //拿到客户端信息
                System.out.println("Client:"+is.readLine());
    
                String line=sin.readLine();
                while (!line.equals("bye")){
                    os.println(line);//输出数据
                    os.flush();//清空缓存
                    System.out.println("Server:"+line);
                    System.out.println("Client:"+is.readLine());
                    line=sin.readLine();
                }
                os.close();
                is.close();
                socket.close();
            }catch (IOException e){
                e.printStackTrace();
            }finally {
                if(serverSocket!=null){
                    serverSocket.close();
                }
            }
        }
    }
    
    
    
    
    //客户端基于socket建立通信
    public class DoubleSocketClient {
    
        public static void main(String[] args) throws IOException {
    
            Socket socket=new Socket("127.0.0.1",8080);
           try {
               //拿到输入流
               BufferedReader sin=new BufferedReader(new InputStreamReader(System.in));
               PrintWriter os=new PrintWriter(socket.getOutputStream());
               BufferedReader is=new BufferedReader(new InputStreamReader(socket.getInputStream()));
               String line=sin.readLine();
               while (!line.equals("bye")){
                   os.println(line);
                   os.flush();//清空
                   System.out.println("Client:"+line);
                   System.out.println("Server:"+is.readLine());
                   line=sin.readLine();
               }
           }finally {
               socket.close();
           }
    
        }
    }