wj----telnet.txt

telnet客户端Telnet 客户端使用 Telnet 协议（TCP/IP 协议套件的一部分）通过网络 连接远程计算机。Telnet 客户端允许计算机连接到远程的 Telnet 服务器并运行该服务器

  import   sun.net.*;     
  import   java.awt.*;     
  import   java.awt.event.*;     
  import   java.applet.*;     
  import   java.io.*;     
    
  public   class   FtpApplet   extends   Applet     
  {     
  FtpClient   aftp;     
  DataOutputStream   outputs   ;     
  TelnetInputStream   ins;     
  TelnetOutputStream   outs;     
  TextArea   lsArea;     
  Label         LblPrompt;     
  Button       BtnConn;     
  Button       BtnClose;     
  TextField     TxtUID;     
  TextField     TxtPWD;     
  TextField     TxtHost;   
      
  int   ch;     
  public   String   a="没有连接主机";     
                  String   hostname="";     
  public   void   init   ()   {     
  setBackground(Color.white);     
  setLayout(new   GridBagLayout());     
  GridBagConstraints   GBC   =   new   GridBagConstraints();     
  LblPrompt   =   new   Label("没有连接主机");     
  LblPrompt.setAlignment(Label.LEFT);     
    
  BtnConn   =   new   Button("连接");     
  BtnClose   =   new   Button("断开");     
  BtnClose.enable(false);     
  TxtUID   =   new   TextField("",15);     
  TxtPWD   =   new   TextField("",15);     
  TxtPWD.setEchoCharacter('*');     
  TxtHost   =   new   TextField("",20);     
  Label   LblUID   =   new   Label("User   ID:");     
  Label   LblPWD   =   new   Label("PWD:");     
  Label   LblHost   =   new   Label("Host:");     
    
  lsArea   =   new   TextArea(30,80);     
  lsArea.setEditable(false);     
    
  GBC.gridwidth=   GridBagConstraints.REMAINDER;     
  GBC.fill           =   GridBagConstraints.HORIZONTAL;     
  ((GridBagLayout)getLayout()).setConstraints(LblPrompt,GBC);     
  add(LblPrompt);     
    
  GBC.gridwidth=1;     
  ((GridBagLayout)getLayout()).setConstraints(LblHost,GBC);     
  add(LblHost);     
  GBC.gridwidth=GridBagConstraints.REMAINDER;     
  ((GridBagLayout)getLayout()).setConstraints(TxtHost,GBC);     
  add(TxtHost);     
    
  GBC.gridwidth=1;     
  ((GridBagLayout)getLayout()).setConstraints(LblUID,GBC);     
  add(LblUID);     
  GBC.gridwidth=1;     
  ((GridBagLayout)getLayout()).setConstraints(TxtUID,GBC);     
  add(TxtUID);     
    
  GBC.gridwidth=1;     
  ((GridBagLayout)getLayout()).setConstraints(LblPWD,GBC);     
  add(LblPWD);     
  GBC.gridwidth=1;     
  ((GridBagLayout)getLayout()).setConstraints(TxtPWD,GBC);     
  add(TxtPWD);     
    
  GBC.gridwidth=1;     
  GBC.weightx=2;     
  ((GridBagLayout)getLayout()).setConstraints(BtnConn,GBC);     
  add(BtnConn);     
  GBC.gridwidth=GridBagConstraints.REMAINDER;     
    
  ((GridBagLayout)getLayout()).setConstraints(BtnClose,GBC);     
  add(BtnClose);     
    
  GBC.gridwidth=GridBagConstraints.REMAINDER;     
  GBC.fill           =   GridBagConstraints.HORIZONTAL;     
  ((GridBagLayout)getLayout()).setConstraints(lsArea,GBC);     
  add(lsArea);     
                  }     
    
  public   boolean   connect(String   hostname,   String   uid,String   pwd)     
  {     
                                  this.hostname   =   hostname;     
  LblPrompt.setText("正在连接，请等待.....");     
  try{     
      aftp   =new   FtpClient(hostname);     
      aftp.login(uid,pwd);     
      aftp.binary();     
      showFileContents();     
  }     
  catch(FtpLoginException   e){     
  a="无权限与主机:"+hostname+"连接!";     
  LblPrompt.setText(a);     
  return   false;     
  }     
  catch   (IOException   e){     
  a="连接主机:"+hostname+"失败!";     
  LblPrompt.setText(a);     
  return   false;     
  }     
  catch(SecurityException   e)     
  {     
  a="无权限与主机:"+hostname+"连接!";     
  LblPrompt.setText(a);     
  return   false;     
  }     
  LblPrompt.setText("连接主机:"+hostname+"成功!");     
  return   true;     
  }     
    
  public   void   stop()     
  {     
  try     
  {     
  aftp.closeServer();     
  }     
  catch(IOException   e)     
  {     
  }     
  }     
    
  public   void   paint(Graphics   g){     
  }     
    
  public   boolean   action(Event   evt,Object   obj)     
  {     
  if   (evt.target   ==   BtnConn)     
  {     
  LblPrompt.setText("正在连接，请等待.....");     
  if   (connect(TxtHost.getText(),TxtUID.getText(),TxtPWD.getText()))     
  {     
  BtnConn.setEnabled(false);     
  BtnClose.setEnabled(true);     
  }     
  return   true;     
  }     
  if   (evt.target   ==   BtnClose)     
  {     
  stop();     
  BtnConn.enable(true);     
  BtnClose.enable(false);     
  LblPrompt.setText("与主机"+hostname+"连接已断开!");     
  return   true;     
  }     
  return   super.action(evt,obj);     
  }     
  public   boolean   sendFile(String   filepathname){     
  boolean   result=true;     
  if   (aftp   !=   null)     
  {     
  LblPrompt.setText("正在粘贴文件,请耐心等待....");     
    
  String     contentperline;     
  try{     
  a="粘贴成功!";     
  String   fg   =new     String("\\");     
  int   index   =   filepathname.lastIndexOf(fg);     
  String   filename   =   filepathname.substring(index+1);     
  File   localFile   ;     
  localFile   =   new   File(filepathname)   ;     
  RandomAccessFile   sendFile   =   new   RandomAccessFile(filepathname,"r");     
  //     
  sendFile.seek(0);     
  outs   =   aftp.put(filename);     
  outputs   =   new   DataOutputStream(outs);     
  while   (sendFile.getFilePointer()   <   sendFile.length()   )     
  {     
      ch   =   sendFile.read();     
      outputs.write(ch);     
  }     
  outs.close();     
  sendFile.close();     
  }     
  catch(IOException   e){     
      a   =   "粘贴失败!";     
      result   =   false   ;     
    
  }     
  LblPrompt.setText(a);     
  showFileContents();     
  }     
  else{     
  result   =   false;     
  }     
  return   result;     
  }     
    
  public   void   showFileContents()     
  {     
  StringBuffer   buf   =   new   StringBuffer();     
  lsArea.setText("");     
  try     
  {     
  ins=   aftp.list();     
  while   ((ch=ins.read())>=0){     
      buf.append((char)ch);     
  }     
          lsArea.appendText(buf.toString());     
  ins.close();     
                  }     
  catch(IOException   e)     
  {     
  }     
  }     
                  public   static   void   main(String   args[]){     
                            Frame   f   =   new   Frame("FTP   Client");     
                            f.addWindowListener(new   WindowAdapter(){     
                                public   void   windowClosing(WindowEvent   e){     
                                        System.exit(0);     
                                }     
    
                            });     
                            FtpApplet   ftp   =   new     FtpApplet();     
                            ftp.init();     
                            ftp.start();     
                            f.add(ftp);     
                            f.pack();     
                            f.setVisible(true);     
                  }     
  }