guestbook.java

模拟留言簿的网络程序,请收下

import java.applet.*;
import java.awt.*;
import java.io.*;
import java.net.*;
import java.util.*;

class smtpSend
{
    static final short PORT = 25;
    String 		lastline;
    DataInputStream in;
    PrintStream p;
    String mailhost, receiver,  sender;
    TextArea scroller = null;
    Socket socket = null;

    smtpSend( String mailhost, String receiver)
    {
   		this.mailhost = mailhost;
   		this.receiver = receiver;
   		this.sender   = receiver;
    }

    public void setScroller(TextArea scroller)
    {
        this.scroller = scroller;
    }

	void expect(String expected, String errorMsg)
	    throws Exception
    {
		lastline = in.readLine();

        if (!lastline.startsWith(expected))
            throw new Exception("Error: " + errorMsg + " (Expected " + expected + ")");

		while (lastline.startsWith(expected + "-"))
		    lastline = in.readLine();
    }

    private void scrollOK()
    {
        scroller.appendText("OK");
    }

    private void openSocket()
        throws Exception
    {
        display("正在与" + mailhost + "相连接...");
        try{
             socket = new Socket(mailhost, PORT);
        } catch (Exception e){
            throw new Exception("Socket Error: Can't connect!");
        }
        scrollOK();
    }

    private void openInputStream()
        throws Exception
    {
        display("正在打开输入流" + "...");
        try{
            in = new DataInputStream(socket.getInputStream());
        }catch (Exception e){
            throw new Exception("Connection Error: Cannot open for input.");
        }
        scrollOK();
    }

    private PrintStream openOutputStream()
        throws Exception
    {
        display("正在打开输出流" + "...");
        try{
            p = new PrintStream(socket.getOutputStream());
        }catch (Exception e){
            throw new Exception("Connection Error: Cannot open for output.");
        }
        scrollOK();
        return p;
    }

    private String getHeloHost()
        throws Exception
    {
        String helohost;
        display("获取本地主机名称" + "...");
        try{
            helohost = InetAddress.getLocalHost().toString();
        }catch (Exception e){
            throw new Exception("Network Error: Unknown Local Host.");
        }
        scrollOK();
        display("本地主机名称：" + helohost + "\r\n");
        return helohost;
    }

    private void display(String string)
    {
        if (null != scroller)
            scroller.appendText("\r\n" + string);
        System.out.println(string);
    }

    private void sendData(String subject, String message)
        throws Exception
    {
        try{
	    	String helohost = getHeloHost();
	    	p.print("HELO " + helohost + "\r\n");
	    	expect("250", "HELO");
	   	    int pos;
	   	    String hello = "Hello ";
	   	    if ((pos = lastline.indexOf(hello)) != -1) {
	   		    helohost = lastline.substring(pos + hello.length());
	   		    helohost = helohost.substring(0, helohost.indexOf(' '));
		    }
		    p.print("MAIL FROM: " + sender + "\r\n");
		    expect("250", "MAIL FROM:");
       		    p.print("RCPT TO: " + receiver + "\r\n");
		    expect("250", "RCPT TO:");
		    p.print("DATA\r\n");
	    	    expect("354", "DATA");
		    p.print("Subject: " + subject);
		    p.print(" (" + helohost + ")");
	    	    p.print("\r\n\r\n");
	    	DataInputStream is = new DataInputStream(new StringBufferInputStream(message));
		    while (is.available() > 0) {
				String ln = is.readLine();
				if (ln.equals("."))
			    ln = "..";
		    	p.println(ln);
		    }
		    p.print(new Date().toGMTString());
                    p.print("\r\n.\r\n");
                    expect("250", "end of data");
	    	    p.print("QUIT\r\n");
		    expect("221", "QUIT");
		}catch(Exception e){
		    throw e;
		}
	}

    public void mailMessage(String subject,String message)
        throws Exception
    {
	    if(null==receiver)throw new Exception("Parameter Error: No RECEIVER");
        try{
         	openSocket();
	    	openOutputStream();
	    	openInputStream();
	    	expect("220", "No greeting");
	    	display("正在通过SMTP发送消息...");
	    	sendData(subject,message);
		} catch(Exception e){
		    throw e;
		}finally{
		    try {
	    		    if(socket != null)socket.close();
	    	} catch(Exception e){}
    	}
    	scrollOK();
    	display("消息已被成功发送-谢谢！");
    	display("请单击『退出』按钮关闭本窗口");
    }
}

class logoPanel extends Canvas
{
    Image image   = null;
    boolean threeD;
    int iWidth, iHeight;
    logoPanel(Image image, boolean threeD)
    {
        this.image = image;
        this.threeD = threeD;
        if(null != image){
            iWidth=image.getWidth(this);
            iHeight=image.getHeight(this);
        }
        else{
            iWidth=400;
            iHeight=100;
        }
        if(threeD)
            resize(iWidth+4,iHeight+4);
        else
            resize(iWidth,iHeight);
    }

    public void paint(Graphics g)
    {
        int x,y;
        g.setColor(Color.lightGray);
        if(threeD){
            x=y=2;
            g.fill3DRect(0,0,size().width,size().height,false);
        }
        else{
            x=y=0;
            g.fillRect(0,0,size().width,size().height);
        }
        if(null != image)
            g.drawImage(image,x,y,this);
    }

    public Dimension minimumSize()
    {
        if(threeD)
            return(new Dimension(iWidth+4,iHeight+4));
        else
            return(new Dimension(iWidth,iHeight));
    }

    public Dimension preferredSize()
    {
        return this.minimumSize();
    }
}

class gbFrame extends tFrame
{
    static final String COPYRIGHT = "Guestbook by Ali";
    TextField tf1,tf2;
    TextArea ta1, ta2;
    tButton sendButton;
    smtpSend smtp;
    gbFrame(String title, smtpSend smtp, Image image, boolean threeD)
    {
        super(title);
        this.smtp=smtp;
        setFont(new Font("System",Font.PLAIN,14));
        GridBagLayout gridbag=new GridBagLayout();
       	GridBagConstraints c=new GridBagConstraints();
       	setLayout(gridbag);
        if(null != image){
            c.insets=new Insets(5,5,8,5);
            c.weightx=1;c.weighty=1;
            c.fill=GridBagConstraints.NONE;
            c.gridwidth=GridBagConstraints.REMAINDER;
            logoPanel lp=new logoPanel(image, threeD);
       	    gridbag.setConstraints(lp,c);
       	    add(lp);
       	}
        c.weightx=1;c.weighty=1;
        c.insets=new Insets(3,5,0,0);
        c.gridwidth=1;
        c.fill=GridBagConstraints.NONE;
        c.anchor=GridBagConstraints.EAST;
        Label label = new Label("用户姓名（可选项）：");
        gridbag.setConstraints(label,c);
       	add(label);