2011最新整理java经典代码

Java实现ftp功能import sun.net.ftp.*; 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);                              )