服务器监听连接。客户端建立连接时。客户端可以发送数据。在当前示例中，客户端发送消息“ Hi my
server”。为了终止连接，客户端发送消息“再见”。然后服务器也发送消息“再见”。最后，连接结束，服务器等待其他连接。这两个程序应在同一台计算机上运行。但是，如果要在两台不同的计算机上运行它们，则可以简单地通过运行服务器的计算机的IP地址来更改地址“
localhost”。
服务器
import java.io.*;import java.net.*;public class Provider{ ServerSocket providerSocket; Socket connection = null; ObjectOutputStream out; ObjectInputStream in; String message; Provider(){} void run() { try{ //1. creating a server socket providerSocket = new ServerSocket(2004, 10); //2. Wait for connection System.out.println("Waiting for connection"); connection = providerSocket.accept(); System.out.println("Connection received from " + connection.getInetAddress().getHostName()); //3. get Input and Output streams out = new ObjectOutputStream(connection.getOutputStream()); out.flush(); in = new ObjectInputStream(connection.getInputStream()); sendMessage("Connection successful"); //4. The two parts communicate via the input and output streams do{ try{ message = (String)in.readObject(); System.out.println("client>" + message); if (message.equals("bye")) sendMessage("bye"); } catch(ClassNotFoundException classnot){ System.err.println("Data received in unknown format"); } }while(!message.equals("bye")); } catch(IOException ioException){ ioException.printStackTrace(); } finally{ //4: Closing connection try{ in.close(); out.close(); providerSocket.close(); } catch(IOException ioException){ ioException.printStackTrace(); } } } void sendMessage(String msg) { try{ out.writeObject(msg); out.flush(); System.out.println("server>" + msg); } catch(IOException ioException){ ioException.printStackTrace(); } } public static void main(String args[]) { Provider server = new Provider(); while(true){ server.run(); } }}客户端
import java.io.*;import java.net.*;public class Requester{ Socket requestSocket; ObjectOutputStream out; ObjectInputStream in; String message; Requester(){} void run() { try{ //1. creating a socket to connect to the server requestSocket = new Socket("localhost", 2004); System.out.println("Connected to localhost in port 2004"); //2. get Input and Output streams out = new ObjectOutputStream(requestSocket.getOutputStream()); out.flush(); in = new ObjectInputStream(requestSocket.getInputStream()); //3: Communicating with the server do{ try{ message = (String)in.readObject(); System.out.println("server>" + message); sendMessage("Hi my server"); message = "bye"; sendMessage(message); } catch(ClassNotFoundException classNot){ System.err.println("data received in unknown format"); } }while(!message.equals("bye")); } catch(UnknownHostException unknownHost){ System.err.println("You are trying to connect to an unknown host!"); } catch(IOException ioException){ ioException.printStackTrace(); } finally{ //4: Closing connection try{ in.close(); out.close(); requestSocket.close(); } catch(IOException ioException){ ioException.printStackTrace(); } } } void sendMessage(String msg) { try{ out.writeObject(msg); out.flush(); System.out.println("client>" + msg); } catch(IOException ioException){ ioException.printStackTrace(); } } public static void main(String args[]) { Requester client = new Requester(); client.run(); }}
