Java服务器使用socket通信

1. 注意
2. 代码

用Java来写一个简单的服务器（server），对客户端（client）的request进行回应。

这个sample主要使用socket来进行演示，分别可以接收与发送string和object。

注意

• 接收与发送object时应使用同一个package的类，且要implements java.io.Serializable。

代码

getString()与getObject()分别是接收string和object，并对其进行回应的方法。

• Main.java

  import java.io.BufferedReader;
  import java.io.BufferedWriter;
  import java.io.InputStreamReader;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.io.OutputStreamWriter;
  import java.io.PrintWriter;
  import java.net.ServerSocket;
  import java.net.Socket;
  import java.util.ArrayList;
  
  public class Main implements Runnable {
      public static final int PORT = 12345;
      private ServerSocket serverSocket;
  
      public void getString(Socket socket) {
          try {
              // receive message
              BufferedReader in = new BufferedReader(new InputStreamReader(
                      socket.getInputStream()));
              String request = in.readLine();
              System.out.println("S: Received: " + request);
  
              // send message
              PrintWriter out = new PrintWriter(new BufferedWriter(
                      new OutputStreamWriter(socket.getOutputStream())), true);
              String response = "S: Received: " + request;
              out.println(response);
              out.flush();
  
              in.close();
              out.close();
          } catch (Exception e) {
              System.out.println("S: Error");
              e.printStackTrace();
          }
      }
  
      public void getObject(Socket socket) {
          try {
              // receive object
              ObjectInputStream in = new ObjectInputStream(
                      socket.getInputStream());
              Object obj = in.readObject();
              ArrayList<Point> points = (ArrayList<Point>) obj;
              System.out.println("S: Received:");
              String request = "";
              for (Point point : points) {
                  request += point.toString() + "\n";
              }
              System.out.println(request);
  
              // send object
              ObjectOutputStream out = new ObjectOutputStream(
                      socket.getOutputStream());
              out.writeObject(points);
              out.flush();
  
              in.close();
              out.close();
          } catch (Exception e) {
              System.out.println("S: Error");
              e.printStackTrace();
          }
      }
  
      public void run() {
          try {
              System.out.println("S: Connecting...");
              serverSocket = new ServerSocket(PORT);
              while (true) {
                  Socket socket = serverSocket.accept();
                  System.out.println("S: Receiving...");
                  try {
                      getObject(socket);
                  } catch (Exception e) {
                      System.out.println("S: Error");
                      e.printStackTrace();
                  } finally {
                      if (socket != null) {
                          socket.close();
                      }
                      System.out.println("S: Done.");
                  }
              }
          } catch (Exception e) {
              System.out.println("S: Error");
              e.printStackTrace();
          }
      }
  
      public static void main(String[] args) {
          Thread thread = new Thread(new Main());
          thread.start();
      }
  }

• Point.java

  public class Point implements java.io.Serializable {
      public double x, y;
  
      public Point(double x, double y) {
          this.x = x;
          this.y = y;
      }
  }