//程序名 :TelnetApp.Java
import java.applet.*;
import java.awt.*;
import java.io.*;
import java.net.*;
import java.util.*;
public class TelnetApp extends Applet implements Runnable
{
//声明成员变量
Thread client;
TextArea log;
TextField hostname;
TextField userid;
TextField password;
Label hname;
Label uid;
Label psd;
Button connect;
Button bye;
int wantTime;
boolean logged;
Socket socket =null;
PrintStream os;
DataInputStream is;
public TelnetApp()
{
resize(400,300);
setLayout(new BorderLayout());
Panel p1=new Panel();
log =new TextArea(10,80);
log.setEditable(true);
p1.add(log);
add("North",p1);
Panel p2=new Panel();
p2.add(hname=new Label("Hostname"));
p2.add(hostname =new TextField(20));
p2.add(uid= new Label("Userid:"));
p2.add(userid =new TextField(10));
p2.add(psd =new Label("Password:"));
p2.add(password =new TextField(10));
password.setEchoCharacter('*');
add("Center",p2);
Panel p3=new Panel();
p3.add(connect =new Button("Connect"));
p3.add(bye =new Button("Bye"));
bye.disable();
add("South",p3);
logged = false;
}
public void run()
{
String fromServer=null;
byte b[]=new byte[3];
b[0]=(byte)'n';
while(true){
if((fromServer =getDate())!= null)
log.appendText(fromServer +"\n");
if(wantTime <0){
bye();
break;
}
if(logged){
delay(60*1000);
log.setText(" ");
wantTime -= 1;
sendData(b,1);
}
}
}
//建立主机连接
private boolean connectHost(String hostName)
{
try{
socket =new Socket(hostName,23);
os =new PrintStream(socket.getOutputStream());
is =new DataInputStream(socket.getInputStream());
}catch(UnknownHostException e){
log.setText("Trying to connect to unknown host:" +e);
return false;
}catch(Exception e){
log.setText("Exception:" +e);
return false;
}
return true;
}
// 接收信息
String getDate()
{
String fromServer;
int len;
byte b[]=new byte[1000];
try{
fromServer ="";
len =is.read(b);
fromServer += new String(b,0);
}catch(Exception e){
log.setText("Exception:"+e);
return null;
}
return fromServer;
}
//发送信息
boolean sendData(byte b[],int len)
{
try{
os.write(b,0,len);
os.flush();
}catch(Exception e){
log.setText("Exception:" + e);
return false;
}
return true;
}
//关闭连接
void closeSocket()
{
try{
os.close();
is.close();
socket.close();
socket = null;
}catch(Exception e){
log.setText("Exception:" +e);
}
}
void toByte(byte[] b,String s)
{
int i;
for(i=0;i<s.length();i++)
b[i]=(byte)s.charAt(i);
b[i] = 13;
b[i+1]=10;
}
void negotiate()
{
byte b[]=new byte[20];
b[0] =-1;b[1]=-5;b[2]=24;
sendData(b,3);
delay(400);
b[0] =-1;b[1]=-6;b[2]=24;
b[3] =0;b[4]=(byte)'D';b[5]=(byte)'E';
b[6] =(byte)'C';b[7]=(byte)'-';b[8]=(byte)'V';
b[9] =(byte)'T';b[10]=(byte)'1';b[11]=(byte)'0';
b[12] =(byte)'0';b[13]=(byte)-1;b[14]=-16;
sendData(b,15);
delay(400);
//其他选项
b[0] =-1;b[1]=-3;b[2]=1;
b[3]=-1;b[4]=-3;b[5]=3;
b[6]=-1;b[7]=-3;b[8]=31;
b[9]=-1;b[10]=-4;b[11]=-56;
b[12]=-1;b[13]=-5;b[14]=1;
sendData(b,15);
delay(400);
//login bbs
toByte(b,"bbs");
sendData(b,5);
delay(400);
}
void login(String userid,String password)
{
byte b[] =new byte[20];
toByte(b,userid);
sendData(b,userid.length()+2);
delay(400);
toByte(b,password);
sendData(b,password.length()+2);
delay(400);
}
boolean enter()
{
if(connectHost(hostname.getText().trim()))
{
log.setText("connected\n");
negotiate();
delay(400);
login(userid.getText().trim(),password.getText().trim());
return true;
} else return false;
}
void toMainmenu()
{
byte b[]=new byte[20];
for(int i=0;i<6;i++)
{
toByte(b," ");
sendData(b,2);
}
for(int i=0;i<1;i++)
{
b[0] =(byte)'q';
sendData(b,1);
delay(200);
}
}
void bye()
{
byte b[]= new byte[20];
for(int i=0;i<10;i++)
{
b[0]=(byte)'q';
sendData(b,1);
delay(300);
}
b[0]=(byte)'g';
sendData(b,1);
delay(300);
for(int i=0;i<6;i++)
{
toByte(b,"");
sendData(b,2);
delay(300);
}
client.stop();
client=null;
closeSocket();
connect.enable();
bye.disable();
}
void delay(int millisecond)
{
try{
Thread.sleep(millisecond);
}catch(InterruptedException e){
}
}
public boolean action(Event e,Object arg)
{
switch(e.id){
case Event.ACTION_EVENT:
if(e.target == connect)
{
wantTime = 20;
connect.disable();
bye.enable();
client =new Thread(this);
client.start();
if(enter())
toMainmenu();
logged =true;
}else if(e.target == bye)
bye();
}
return true;
}
public void destroy(){
}
public void paint(Graphics g){}
public void start(){}
public void stop(){
}
}
