exercise20_1client.java

这是一个基于JAVA的网络编程的例子

/*
写程序实现并发的客户机-服务器以计算长方体的面积和体积
*/
import java.io.*;
import java.net.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Exercise20_1Client extends JFrame implements ActionListener {
  private JTextField jtfLength = new JTextField();
  private JTextField jtfWidth = new JTextField();
  private JTextField jtfHigh = new JTextField();
  private JButton jbtSubmit= new JButton("Submit");
  private JTextArea jta = new JTextArea();
  private DataOutputStream osToServer;
  private DataInputStream isFromServer;
  public static void main(String[] args) {
    new Exercise20_1Client();
  }
  public Exercise20_1Client() {
    JPanel p1 = new JPanel();
    p1.setLayout(new GridLayout(3, 1));
    p1.add(new JLabel("Length"));
    p1.add(new JLabel("Width"));
    p1.add(new JLabel("High"));
    Panel p2 = new Panel();
    p2.setLayout(new GridLayout(3, 1));
    p2.add(jtfLength);
    p2.add(jtfWidth);
    p2.add(jtfHigh);
    JPanel p = new JPanel();
    p.setLayout(new BorderLayout());
    p.add(p1, BorderLayout.WEST);
    p.add(p2, BorderLayout.CENTER);
    p.add(jbtSubmit, BorderLayout.EAST);
    jtfLength.setHorizontalAlignment(JTextField.RIGHT);
    jtfWidth.setHorizontalAlignment(JTextField.RIGHT);
    jtfHigh.setHorizontalAlignment(JTextField.RIGHT);
    getContentPane().setLayout(new BorderLayout());
    getContentPane().add(p, BorderLayout.NORTH);
    getContentPane().add(new JScrollPane(jta), BorderLayout.CENTER);
    jbtSubmit.addActionListener(this);
    jta.setWrapStyleWord(true);
    jta.setLineWrap(true);
    setTitle("Exercise20_1Client");
    setSize(500, 300);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setVisible(true);
    try {
      Socket connectToServer = new Socket("localhost", 8000);
      isFromServer = new DataInputStream(
        connectToServer.getInputStream());
     osToServer = new DataOutputStream(connectToServer.getOutputStream());
    }
    catch (IOException ex) {
      jta.append(ex.toString() + '\n');
    }
  }
  public void actionPerformed(ActionEvent e) {
    String actionCommand = e.getActionCommand();
    if (e.getSource() instanceof JButton) {
      try {
        double length =
          Double.parseDouble(jtfLength.getText().trim());
        double width =
          Double.parseDouble(jtfWidth.getText().trim());
        double high =
          Double.parseDouble(jtfHigh.getText().trim());
        osToServer.writeDouble(length);
        osToServer.writeDouble(width);
        osToServer.writeDouble(high);
        osToServer.flush();
        double area = isFromServer.readDouble();
        double volume = isFromServer.readDouble();
          jta.append("Length: " + length +
            " Width: " + width + " High: " +
            high + "\n");
          jta.append(" Area: " + area + " " +
            " Volume: " + volume + '\n');
      }
      catch (IOException ex) {
        System.err.println(ex);
      }
    }
  }
}