JTextArea实现右键复制，粘贴，删除等功能！

package rightMouse;

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.MouseEvent;

import java.awt.event.MouseListener;

import javax.swing.JMenuItem;

import javax.swing.JPopupMenu;

import javax.swing.JSeparator;

import javax.swing.JTextArea;

import javax.swing.undo.UndoManager;

public class TextAreaMenu extends JTextArea implements MouseListener {

/**

*

*/

private static final long serialVersionUID = 1L;

private JPopupMenu pm=null;

private JMenuItem copy=null;

private JMenuItem delete=null;

private JMenuItem cut=null;

private JMenuItem undo=null;

private JMenuItem paste=null;

private JMenuItem redo=null;

private JMenuItem selectAll=null;

//添加撤消管理器

private UndoManager um=new UndoManager();

public TextAreaMenu()

{

super();

init();

}

public TextAreaMenu(String str)

{

super(str);

init();

}

private void init()

{

this.addMouseListener(this);

this.getDocument().addUndoableEditListener(um);

pm=new JPopupMenu();

//全选

selectAll=new JMenuItem("全选");

selectAll.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {

action(e);

}

});

//粘贴

paste=new JMenuItem("粘贴");

paste.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {

action(e);

}

});

//复制

copy=new JMenuItem("复制");

copy.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {

action(e);

}

});

//删除

delete=new JMenuItem("删除");

delete.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {

action(e);

}

});

//剪切

cut=new JMenuItem("剪切");

cut.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {

action(e);

}

});

//撤消

undo=new JMenuItem("撤消");

undo.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {

action(e);

}

});

//返回

redo=new JMenuItem("返回");

redo.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {

action(e);

}

});

pm.add(selectAll);

pm.add(delete);

pm.add(new JSeparator());

pm.add(copy);

pm.add(cut);

pm.add(paste);

pm.add(new JSeparator());

pm.add(undo);

pm.add(redo);

this.add(pm);

}

//

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;

}

//

public boolean isCanCopy()

{

boolean b = false;

int start = this.getSelectionStart();

int end = this.getSelectionEnd();

if (start != end)

b = true;

return b;

}

@Override

public void mouseClicked(MouseEvent arg0) {

// TODO Auto-generated method stub

}

@Override

public void mouseEntered(MouseEvent arg0) {

// TODO Auto-generated method stub

}

@Override

public void mouseExited(MouseEvent arg0) {

// TODO Auto-generated method stub

}

@Override

public void mousePressed(MouseEvent e) {

// TODO Auto-generated method stub

if(e.getButton() == MouseEvent.BUTTON3)

{

delete.setEnabled(isCanCopy());

copy.setEnabled(isCanCopy());

paste.setEnabled(isClipboardString());

cut.setEnabled(isCanCopy());

undo.setEnabled(um.canUndo());

redo.setEnabled(um.canRedo());

pm.show(this, e.getX(), e.getY());

}

}

@Override

public void mouseReleased(MouseEvent arg0) {

// TODO Auto-generated method stub

}

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();

}

else if(str.equals(undo.getText()))

{

um.undo();

}

else if(str.equals(redo.getText()))

{

um.redo();

}

else if(str.equals(delete.getText()))

{

this.replaceSelection("");

}

else if(str.equals(selectAll.getText()))

{

this.selectAll();

}

}

}