Java右键菜单实现文本组件内容的的复制、粘贴、剪切功能

import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.InputEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.KeyStroke;
import javax.swing.UIManager;

/**
 * Java右键菜单实现文本组件内容的的复制、粘贴、剪切功能
 *
 * @author 
 * @blog www.cnblogs.com/zhm
 */

public class Test extends JFrame {

 private static final long serialVersionUID = -5942087991012920147L;

 private JScrollPane pane = null;

 private TextAreaMenu text = null;

 public Test() {
  super("右键菜单");
  try { // 使用Windows的界面风格
   UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
  } catch (Exception e) {
   e.printStackTrace();
  }
  text = new TextAreaMenu();
  pane = new JScrollPane(text);
  this.getContentPane().add(pane);
  this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  this.setSize(300, 200);
  this.setVisible(true);
 }

 public static void main(String args[]) {
  new Test();
 }

 /**
  * 带有功能菜单的JTextArea
  *
  * @author
  * @blog www.cnblogs.com/zhm
  */
 class TextAreaMenu extends JTextArea implements MouseListener {

  private static final long serialVersionUID = -2308615404205560110L;

  private JPopupMenu pop = null; // 弹出菜单

  private JMenuItem copy = null, paste = null, cut = null; // 三个功能菜单

  public TextAreaMenu() {
   super();
   init();
  }

  private void init() {
   this.addMouseListener(this);
   pop = new JPopupMenu();
   pop.add(copy = new JMenuItem("复制"));
   pop.add(paste = new JMenuItem("粘贴"));
   pop.add(cut = new JMenuItem("剪切"));
   copy.setAccelerator(KeyStroke.getKeyStroke('C', InputEvent.CTRL_MASK));
   paste.setAccelerator(KeyStroke.getKeyStroke('V', InputEvent.CTRL_MASK));
   cut.setAccelerator(KeyStroke.getKeyStroke('X', InputEvent.CTRL_MASK));
   copy.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
     action(e);
    }
   });
   paste.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
     action(e);
    }
   });
   cut.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
     action(e);
    }
   });
   this.add(pop);
  }

  /**
   * 菜单动作
   * @param e
   */
  public void action(ActionEvent e) {
   String str = e.getActionCommand();
   if (str.equals(copy.getText())) { // 复制
    this.copy();
   } else if (str.equals(paste.getText())) { // 粘贴
    this.paste();
   } else if (str.equals(cut.getText())) { // 剪切
    this.cut();
   }
  }

  public JPopupMenu getPop() {
   return pop;
  }

  public void setPop(JPopupMenu pop) {
   this.pop = pop;
  }

  /**
   * 剪切板中是否有文本数据可供粘贴
   *
   * @return true为有文本数据
   */
  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;
  }

  /**
   * 文本组件中是否具备复制的条件
   *
   * @return true为具备
   */
  public boolean isCanCopy() {
   boolean b = false;
   int start = this.getSelectionStart();
   int end = this.getSelectionEnd();
   if (start != end)
    b = true;
   return b;
  }

  public void mouseClicked(MouseEvent e) {
  }

  public void mouseEntered(MouseEvent e) {
  }

  public void mouseExited(MouseEvent e) {
  }

  public void mousePressed(MouseEvent e) {
   if (e.getButton() == MouseEvent.BUTTON3) {
    copy.setEnabled(isCanCopy());
    paste.setEnabled(isClipboardString());
    cut.setEnabled(isCanCopy());
    pop.show(this, e.getX(), e.getY());
   }
  }

  public void mouseReleased(MouseEvent e) {
  }

 }

}