loginscreen.java

基于swing的java模拟的c/s服务模式

package clients;

import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.KeyStroke;

public class LoginScreen extends JFrame implements ActionListener {
	private static final long serialVersionUID = 1L;

	private static JButton cancelbutton = new JButton("取消");

	private static JButton okbutton = new JButton("登陆");

	private static JLabel passlabel = new JLabel("密码");

	private static JLabel userlabel = new JLabel("用户名");

	public JPasswordField passtext = new JPasswordField(20);

	public JTextField usertext = new JTextField(20);

	public static void main(String args[]) {
		JFrame screen = new LoginScreen();
		screen.repaint();
		screen.setVisible(true);
		screen.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
	}

	public LoginScreen() {
		super("FTP用户登陆");
		initialize();
	}

	public LoginScreen(String args) {
		super("FTP用户登陆");
		initialize();
	};

	private void initialize() {
		setLocation(450, 250);
		setSize(300, 150);
		setResizable(false);
		this.getContentPane().setLayout(null);
		userlabel.setBounds(new Rectangle(15, 20, 60, 20));
		passlabel.setBounds(new Rectangle(15, 50, 60, 20));
		usertext.setBounds(80, 20, 160, 20);
		passtext.setBounds(new Rectangle(80, 50, 160, 20));
		okbutton.setBounds(new Rectangle(80, 80, 60, 20));
		cancelbutton.setBounds(new Rectangle(150, 80, 60, 20));
		getContentPane().add(userlabel);
		getContentPane().add(passlabel);
		getContentPane().add(usertext);
		getContentPane().add(passtext);

		getContentPane().add(okbutton);
		getContentPane().add(cancelbutton);
		ActionListener s = new ActionListener() {
			public void actionPerformed(ActionEvent evt) {
				login();
			}
		};
		this.getRootPane().registerKeyboardAction(s,
				KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0, false),
				JComponent.WHEN_IN_FOCUSED_WINDOW);

		okbutton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent evt) {
				login();
			}
		});

		cancelbutton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent evt) {
				System.exit(0);
			}
		});
	}

	public void login() {
		String name = usertext.getText();
		String pass = new String(passtext.getPassword());
		if (name.equals("")) {
			JOptionPane.showMessageDialog(this, "用户名不能为空");
			usertext.requestFocus();
			return;
		} else if (pass.equals("")) {
			JOptionPane.showMessageDialog(this, "密码不能为空");
			passtext.setText("");
			passtext.requestFocus();
			return;
		}
		check(name, pass);
	}

	public void check(String username, String pass) {
		String name = username;
		String password = pass;

		openConnect(name, password);
	}

	public void openConnect(String name, String password) {
		String text = "userlogin@user@" + name + "@password@" + password;
		Socket s = null;
		try {
			s = new Socket("localhost", 21);
		} catch (UnknownHostException e) {
			JOptionPane.showMessageDialog(this, "无法连FTP接服务器");
		} catch (IOException e) {
			JOptionPane.showMessageDialog(this, "无法连接FTP服务器");
		}
		if (s != null) {
			PrintWriter out = null;
			try {
				out = new PrintWriter(s.getOutputStream());
			} catch (IOException e) {
				JOptionPane.showMessageDialog(this, "数据传输异常");
			}
			out.println(text);
			out.flush();
			redirect(s, name);
		}
	}

	public void redirect(Socket s, String user) {
		BufferedReader bu = null;
		try {
			bu = new BufferedReader(new InputStreamReader(s.getInputStream()));
		} catch (IOException e) {
			e.printStackTrace();
		}
		try {
			String line = bu.readLine();
			if (line.equals("true")) {
				dispose();
				new FtpUserScreen(user, s);
			} else {
				JOptionPane.showMessageDialog(this, "用户名或密码有误");
				usertext.setText("");
				passtext.setText("");
				usertext.requestFocus();
			}
		} catch (IOException e) {
			JOptionPane.showMessageDialog(this, "数据传输有误");
		}
	}

	public void actionPerformed(ActionEvent arg0) {
	}

}