guestbook.java

一个初学者的例子

import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;
import java.applet.*;
import java.io.*;
import java.net.*;
import java.util.*;
import javax.swing.*;

public class guestbook extends Applet implements MouseMotionListener, MouseListener,Runnable, ActionListener  {

  Thread t;  //main thread

  Graphics grBuffer;  //main graphics object
  Image imgBuffer;

  int height,width;  //height and width of applet

  boolean viewing,signing;

  String name[] = new String [50000];
  String email[] = new String [50000];
  String web[] = new String [50000];
  String comment[] = new String [50000];
  String lines[] = new String [200000];
  int entryLines[]=new int [50000];
  int finishLines[]=new int [50000];

  int numEntries=0;
  int numLines=0;

  boolean upScrol,downScrol;
  int Scrol;
  TextArea txtComment;
  TextField txtName;
  TextField txtWeb;
  TextField txtEmail;
  Button btnSign;

  int paintDelay=0;

static int randomNumber (int low, int high) {
   		// returns a random number between low and high, inclusive
   		return (int)(java.lang.Math.random() * (high - low + 1) + low);
	} // randomNumber


public void init () {
height = 600;      //get height and width
width = 800;

imgBuffer = createImage (width, height); //make buffer image
grBuffer = imgBuffer.getGraphics ();    //associate buffer with buffer image
viewing=true;
grBuffer.setFont (new Font ("Courier", Font.PLAIN , 12));
this.addMouseMotionListener (this);
				this.addMouseListener (this);

setLayout(null);
txtComment=new TextArea();
txtComment.setBounds(190,320,500,200);
txtName=new TextField();
txtName.setBounds(190,110,500,20);
txtEmail=new TextField();
txtEmail.setBounds (190,180,500,20);
txtWeb=new TextField();
txtWeb.setBounds (190,250,500,20);
btnSign=new Button ("SIGN");
btnSign.setBounds (362,550,75,35);
btnSign.addActionListener(this);


newView ();
} //inint





public void paint (Graphics g) {
int p,t,a;
paintDelay++;
if (paintDelay>=3) {
grBuffer.setColor (Color.gray);
grBuffer.fillRect (0,0,width,height);
grBuffer.setColor (Color.yellow);
grBuffer.fillRect (275,10,100,50);
grBuffer.fillRect (425,10,100,50);
grBuffer.setColor (Color.black);
grBuffer.drawRect (275,10,100,50);
grBuffer.drawRect (425,10,100,50);
grBuffer.drawString ("SIGN",308,40);
grBuffer.drawString ("VIEW",458,40);
grBuffer.drawLine (0,80,800,80);

if (viewing==true) {
	grBuffer.setColor (Color.white);
	grBuffer.fillRect (20,100,700,480);
	grBuffer.setColor (Color.yellow);
	grBuffer.fillRect (745,100,30,480);
	grBuffer.setColor (Color.black);
	grBuffer.drawRect (20,100,700,480);
	grBuffer.drawRect (745,100,30,480);
	grBuffer.drawLine (745,130,775,130);
	grBuffer.drawLine (745,340,775,340);
	grBuffer.drawLine (745,550,775,550);
	grBuffer.drawLine (760,105,760,125);
	grBuffer.drawLine (760,555,760,575);
	grBuffer.drawLine (760,105,750,115);
	grBuffer.drawLine (760,105,770,115);
	grBuffer.drawLine (760,575,750,565);
	grBuffer.drawLine (760,575,770,565);
	a=0;
	p=Scrol;
	int v=0;
	while (a<33) {
		if (p<numLines) {
		//	if (x>25 && y>103+(a*14) && x<25+(lines[p].length()*7) && y<116+(a*14))

		for (v=0;v<numEntries;v++) if (entryLines[v]==p+2) grBuffer.drawLine (25,114+(a*14),25+lines[p].length()*7,114+(a*14));
		grBuffer.drawString (lines[p],25,113+(a*14));
		}
		a=a+1;
		if (p<numLines)
		for (t=0;t<numEntries;t++) {
			if (finishLines[t]==p+1) {
			grBuffer.drawLine (25,113+(a*14),720,113+(a*14));
			a++;
			}//if
		}// for t
		p=p+1;
	}//while




}

if (signing==true) {
	grBuffer.setFont (new Font ("Courier", Font.BOLD , 14));
	grBuffer.setColor (Color.black);
	grBuffer.drawString ("Name:",25,123);
	grBuffer.drawString ("Email: (optional)",25,193);
	grBuffer.drawString ("Website: (optional)",25,263);
	grBuffer.drawString ("Comment:",25,333);
	grBuffer.setFont (new Font ("Courier", Font.PLAIN , 12));
}


g.drawImage (imgBuffer, 0, 0, this);
paintDelay=0;
}
}

private void sendData () {
	System.out.println ("sending...");
	String IPAdd="";
	int port=0;
	Socket clientsocket;
	DataOutputStream out;
	IPAdd = getParameter("IPAdd");
	port=Integer.parseInt (getParameter("PortNumber"));

	try {
	            clientsocket = new Socket(IPAdd, port);                    //IPAdd  "localHost"
	           	out = new DataOutputStream(clientsocket.getOutputStream());

	           	String msg="";
				msg=txtName.getText()+"!@#ZX"+txtEmail.getText()+"!@#ZX"+txtWeb.getText()+"!@#ZX"+txtComment.getText()+"!@#ZX";

				out.writeUTF(msg);
				out.close();

} catch (Exception e) {
	System.out.println ("Couldnt connect to server");
} //exception





}//senddata

private void newView () {
String fileName;
fileName = getParameter("fileName");
int tempInt1=0;
char charRead='a';
String tempString="";
int p,t,a;
numEntries=0;
a=0;
try {
			URL url = new URL(getCodeBase(), fileName);

			try {
				BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
               do {
                    tempInt1=in.read();
                    charRead= (char) (tempInt1);
                    tempString=tempString + charRead;
                    if (tempString.endsWith ("!@#ZX")) {
					if (a==0)
						name[numEntries]=tempString.substring (0,tempString.length()-5);
					if (a==1)
						email[numEntries]=tempString.substring (0,tempString.length()-5);
					if (a==2)
						web[numEntries]=tempString.substring (0,tempString.length()-5);
					if (a==3)
						comment[numEntries]=tempString.substring (0,tempString.length()-5);
					a=a+1;
					if (a==4) {
						a=0;
						numEntries++;
					}
					tempString="";



					}//endswith
					} while (tempInt1 != -1);
					in.close ();
			} catch (IOException e) { }
		} catch (MalformedURLException e) { }
a=0;
t=0;
int g=0;
for (p=0;p<numEntries;p++){
	lines[a++]=name[p];
	lines[a++]=email[p];
	lines[a++]=web[p];
	entryLines[p]=a+1;
	g=0;
	comment[p]=comment[p]+(char) (10);
	for (t=0;t<comment[p].length();t++) {
	if ((int) (comment[p].charAt (t)) == 10) {
	if (t-g>1) lines[a++]=comment[p].substring (g,t); else {
			if (comment[p].charAt(g)!=(char) (13)) lines[a++]=comment[p].substring (g,t); else
			lines[a++]=" ";
			}
	g=t+1;
	}//if
	}//t


	finishLines[p]=a;
}//p
numLines=a;




}//newview

 public void run() {
while (true) {

if (downScrol==true) {
if (Scrol+26<numLines) {
Scrol+=1;
 	if (Scrol>500000) Scrol=500000;
}

}

if (upScrol==true) {
Scrol-=1;
	if (Scrol<0) Scrol=0;
}


repaint ();

try {
	t.sleep(75);
	} catch (InterruptedException e) {  }

} //while
} //run


public void start() {


        if (t==null) {
           t = new Thread(this);
        }

           t.start();
}

public void stop() {
           t = null;

}
public void update (Graphics g) {

        paint (g);
    }

public void mouseMoved (MouseEvent me) {

}

public void mouseClicked (MouseEvent me) {
	int x,y,p,a,t;
	x=me.getX();
	y=me.getY();
if (viewing==true) {
	if (x>745 && x<775 && y>100 && y<340) Scrol--;
	if (Scrol+26<numLines) if (x>745 && x<775 && y>340 && y<580) Scrol++;
	if (Scrol<0) Scrol=0;

	p=Scrol;
	a=0;
	while (a<33) {
	if (p<numLines)
			if (x>25 && y>103+(a*14) && x<25+(lines[p].length()*7) && y<116+(a*14)) {
			if (lines[p].indexOf ("http://")==0 || lines[p].indexOf ("www.")==0) {
			try {URL url = new URL(getCodeBase(),lines[p]);
			getAppletContext().showDocument(url, "_new");
	 		} catch (MalformedURLException f) { }
			}
			if (lines[p].indexOf ("@")!=-1 ) {
			try {URL url1 = new URL(getCodeBase(),"mailto:"+lines[p]);
			getAppletContext().showDocument(url1, "_new");
	 		} catch (MalformedURLException f) { }
			}
			}

			a=a+1;
			if (p<numLines)
			for (t=0;t<numEntries;t++) if (entryLines[t]==p+1) a++;
			p++;
	}//while
} // chooseSymb

if (x>275 && y>10 && x<375 && y<60) {
	signing=true;
	viewing=false;
	add(txtName);
	add(txtEmail);
	add(txtWeb);
	add(txtComment);
	add(btnSign);



}

if (x>425 && y>10 && x<525 && y<60) {
	newView();
	viewing=true;
	signing=false;
	remove(txtName);
	remove(txtComment);
	remove(txtEmail);
	remove(txtWeb);
	remove(btnSign);

}


}

public void mouseDragged (MouseEvent e) {

    }
public void mousePressed (MouseEvent me) {
	int x,y,t,p;
			x=me.getX();
			y=me.getY();


	if (viewing==true) {

	if (x>745 && x<775 && y>100 && y<340)
		upScrol=true;

	//check for scroll bar

	if (x>745 && x<775 && y>340 && y<580)
		downScrol=true;

	}


}
public void mouseReleased (MouseEvent me) {
		downScrol=false;
		upScrol=false;
}
public void mouseEntered (MouseEvent me) {
}
public void mouseExited (MouseEvent me) {


}

public void actionPerformed(ActionEvent e) {
	if (e.getSource()==btnSign) {
	sendData ();
	viewing=true;
		signing=false;
		remove(txtName);
		remove(txtComment);
		remove(txtEmail);
		remove(txtWeb);
		remove(btnSign);
	}
	int z=0;
	for (int p=0;p<1000000;p++) {
		int a=p;
		p=p*p;
		p=a;
		z=z+10/2+p/2;
	}

	newView ();


}




} //class spacefly