在学习JPopupMenud的过程中，做了一个小软件。实现了多个文本框，同时使用右键弹出菜单，并实现复制、粘贴、剪切功能。

实际上在网上查的时候，网上有一个很普遍的右键复制、粘贴、剪切的功能（http://blog.csdn.net/xinem/article/details/3866904）。我抄过来发现可以实现功能，但不是很懂怎么实现复制、粘贴、和剪切功能。于是自己摸索了，写了一个。

这个小软件，主要实现了两个文本框同时可以使用右键弹出菜单的复制、粘贴、剪切功能。

小软件的界面用netbeans画出来的，包括JPopupMenu都是这样子的。

这个软件，部分代码用了网上那个流传广泛的代码。

以下是我的软件代码：

/** To change this license header, choose License Headers in Project Properties.* To change this template file, choose Tools | Templates* and open the template in the editor.*/import java.awt.Toolkit;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.StringSelection;
import java.awt.datatransfer.Transferable;
import java.awt.event.ActionEvent;
import java.awt.event.MouseEvent;
import javax.swing.JTextField;/**** @author peade*/
public class NewJFrame extends javax.swing.JFrame {/*** Creates new form NewJFrame*/public NewJFrame() {initComponents();//将右键弹出菜单添加到文本框jTextField1.setComponentPopupMenu(jPopupMenu1);jTextField2.setComponentPopupMenu(jPopupMenu1);}/*** This method is called from within the constructor to initialize the form.* WARNING: Do NOT modify this code. The content of this method is always* regenerated by the Form Editor.*/@SuppressWarnings("unchecked")// <editor-fold defaultstate="collapsed" desc="Generated Code">                          private void initComponents() {jPopupMenu1 = new javax.swing.JPopupMenu();copyb = new javax.swing.JMenuItem();pasteb = new javax.swing.JMenuItem();cutb = new javax.swing.JMenuItem();jTextField1 = new javax.swing.JTextField();jTextField2 = new javax.swing.JTextField();jLabel1 = new javax.swing.JLabel();jLabel2 = new javax.swing.JLabel();copyb.setAccelerator(javax.swing.KeyStroke.getKeyStroke(java.awt.event.KeyEvent.VK_C, java.awt.event.InputEvent.CTRL_MASK));copyb.setText("复制");copyb.addActionListener(new java.awt.event.ActionListener() {public void actionPerformed(java.awt.event.ActionEvent evt) {copybActionPerformed(evt);}});jPopupMenu1.add(copyb);pasteb.setAccelerator(javax.swing.KeyStroke.getKeyStroke(java.awt.event.KeyEvent.VK_V, java.awt.event.InputEvent.CTRL_MASK));pasteb.setText("粘贴");pasteb.addActionListener(new java.awt.event.ActionListener() {public void actionPerformed(java.awt.event.ActionEvent evt) {pastebActionPerformed(evt);}});jPopupMenu1.add(pasteb);cutb.setAccelerator(javax.swing.KeyStroke.getKeyStroke(java.awt.event.KeyEvent.VK_X, java.awt.event.InputEvent.CTRL_MASK));cutb.setText("剪切");cutb.addActionListener(new java.awt.event.ActionListener() {public void actionPerformed(java.awt.event.ActionEvent evt) {cutbActionPerformed(evt);}});jPopupMenu1.add(cutb);setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);jTextField1.addMouseListener(new java.awt.event.MouseAdapter() {public void mousePressed(java.awt.event.MouseEvent evt) {jTextField1MousePressed(evt);}});jTextField2.addMouseListener(new java.awt.event.MouseAdapter() {public void mousePressed(java.awt.event.MouseEvent evt) {jTextField2MousePressed(evt);}});jLabel1.setText("文本框1");jLabel2.setText("文本框2");javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());getContentPane().setLayout(layout);layout.setHorizontalGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addGroup(layout.createSequentialGroup().addContainerGap().addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addComponent(jLabel1).addComponent(jLabel2)).addGap(22, 22, 22).addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false).addComponent(jTextField1).addComponent(jTextField2, javax.swing.GroupLayout.DEFAULT_SIZE, 222, Short.MAX_VALUE)).addContainerGap(82, Short.MAX_VALUE)));layout.setVerticalGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addGroup(layout.createSequentialGroup().addGap(30, 30, 30).addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE).addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE).addComponent(jLabel1)).addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED).addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE).addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE).addComponent(jLabel2)).addContainerGap(43, Short.MAX_VALUE)));pack();}// </editor-fold>                        
// 三个按键事件添加private void copybActionPerformed(java.awt.event.ActionEvent evt) {                                      // getInvoker() 判断右键菜单来源于哪个文本框if(jPopupMenu1.getInvoker()==jTextField1){copybAction(evt,jTextField1);}if(jPopupMenu1.getInvoker()==jTextField2){copybAction(evt,jTextField2);}// TODO add your handling code here:}                                     private void pastebActionPerformed(java.awt.event.ActionEvent evt) {                                       if(jPopupMenu1.getInvoker()==jTextField1){pastebAction(evt,jTextField1);}if(jPopupMenu1.getInvoker()==jTextField2){pastebAction(evt,jTextField2);}// TODO add your handling code here:}                                      private void cutbActionPerformed(java.awt.event.ActionEvent evt) {                                     if(jPopupMenu1.getInvoker()==jTextField1){cutbAction(evt,jTextField1);}if(jPopupMenu1.getInvoker()==jTextField2){cutbAction(evt,jTextField2);}// TODO add your handling code here:}                                    
//在文本框中进行功能是否可用判断private void jTextField1MousePressed(java.awt.event.MouseEvent evt) {                                         judge(evt,jTextField1);// TODO add your handling code here:}                                        private void jTextField2MousePressed(java.awt.event.MouseEvent evt) {                                         judge(evt,jTextField2);// TODO add your handling code here:}                                        /*** @param args the command line arguments*/public static void main(String args[]) {/* Set the Nimbus look and feel *///<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html */try {for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {if ("Nimbus".equals(info.getName())) {javax.swing.UIManager.setLookAndFeel(info.getClassName());break;}}} catch (ClassNotFoundException ex) {java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);} catch (InstantiationException ex) {java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);} catch (IllegalAccessException ex) {java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);} catch (javax.swing.UnsupportedLookAndFeelException ex) {java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);}//</editor-fold>/* Create and display the form */java.awt.EventQueue.invokeLater(new Runnable() {public void run() {new NewJFrame().setVisible(true);}});}//粘贴功能private void pastebAction(ActionEvent evt, JTextField textField) {  //以下三行获取剪切板的值Clipboard clip = this.getToolkit().getSystemClipboard(); Transferable contents=clip.getContents(this);DataFlavor flavor=DataFlavor.stringFlavor;String str = null;String s=textField.getText();if(contents.isDataFlavorSupported(flavor)){try{//剪切板的值转移到str中str=(String)contents.getTransferData(flavor);int start=textField.getSelectionStart();int end=textField.getSelectionEnd();if(start==end){if(start==0){s=str+s;textField.setText(s);textField.setCaretPosition(str.length());}else if(start==s.length()){s=s+str;textField.setText(s);textField.setCaretPosition(s.length());}else{String s1=s.substring(0,start);  String s2=s.substring(start);s=s1+str+s2;textField.setText(s);textField.setCaretPosition(s1.length()+str.length());}}else{String s1=s.substring(0,start);  String s2=s.substring(end);s=s1+str+s2;textField.setText(s);textField.setCaretPosition(s1.length()+str.length());}}catch(Exception e){e.printStackTrace();}}}  //复制功能private void copybAction(ActionEvent evt, JTextField textField) {                                      int start=textField.getSelectionStart();int end=textField.getSelectionEnd();String s=textField.getText();String cp=s.substring(start,end);sendtoClipboard(cp);// TODO add your handling code here:}  //剪切功能private void cutbAction(java.awt.event.ActionEvent evt, JTextField TextField) {                                     int start=TextField.getSelectionStart();int end=TextField.getSelectionEnd();String s=TextField.getText();String cs=s.substring(start,end);sendtoClipboard(cs);s=s.substring(0,start)+s.substring(end);TextField.setText(s);// TODO add your handling code here:}    // 将文本发送到系统剪切板protected void sendtoClipboard(String st){Toolkit kit=Toolkit.getDefaultToolkit();Clipboard sysClip = Toolkit.getDefaultToolkit().getSystemClipboard();StringSelection   ss=new   StringSelection(st);sysClip.setContents(ss, null);}//判断能否进行复制剪切public boolean isCanCopy(JTextField textField) {  boolean b = false;  int start = textField.getSelectionStart();  int end = textField.getSelectionEnd();  if (start != end)  b = true;  return b;  }  //判断能否进行粘贴public boolean isClipboardString() {  boolean b = false;  Clipboard clipboard = this.getToolkit().getSystemClipboard();  Transferable content = clipboard.getContents(this);  try {  if (content.getTransferData(DataFlavor.stringFlavor) instanceof String) {  b = true;  }  } catch (Exception e) {  }  return b;  }// 判断复制粘贴剪切在具体文本框中，该功能是否可用protected void judge(MouseEvent evt, JTextField TextField){if (evt.getButton() == MouseEvent.BUTTON3){copyb.setEnabled(isCanCopy(TextField));cutb.setEnabled(isCanCopy(TextField));pasteb.setEnabled(isClipboardString());}}// Variables declaration - do not modify                     private javax.swing.JMenuItem copyb;private javax.swing.JMenuItem cutb;private javax.swing.JLabel jLabel1;private javax.swing.JLabel jLabel2;private javax.swing.JPopupMenu jPopupMenu1;private javax.swing.JTextField jTextField1;private javax.swing.JTextField jTextField2;private javax.swing.JMenuItem pasteb;// End of variables declaration                   
}