package notepad;import java.awt.Toolkit;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.ItemEvent;import java.awt.event.ItemListener;import java.awt.event.MouseEvent;import java.awt.event.MouseListener;import java.io.BufferedWriter;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import javax.swing.JFrame;import javax.swing.JMenuItem;import javax.swing.JPopupMenu;import javax.swing.JScrollPane;import javax.swing.JTextArea;import javax.swing.event.MenuEvent;import javax.swing.event.MenuListener;import javax.swing.event.UndoableEditEvent;import javax.swing.event.UndoableEditListener;import javax.swing.undo.UndoManager;/** * *@author huyongjian Oracle(Compus Solution Group) * @Date 2013-7-26 * @version 2.0 * @since JDK1.6（建议）Copy Right Information COMPUS SOLUTION GROUPIDE:Eclipseclass:文本编辑区 */public class TextArea extends JTextArea implements MouseListener,UndoableEditListener,MenuListener,ActionListener,ItemListener{private static final long serialVersionUID = 1L;public boolean Saved;public String Name,Path;public JScrollPane Pane;public JPopupMenu Popup;public JMenuItem Redo,Undo,Cut,Copy,Paste,Delete,SelectAll,FindAndReplace;public UndoManager Manager;public MenuList menu;public FindAndReplace find;TextArea(JFrame notepad,int x,int y){super();Saved=true;Name=null;Path=null;Popup=new JPopupMenu();Undo=new JMenuItem(” 撤消”);Redo=new JMenuItem(” Redo”);Cut=new JMenuItem(” 剪切”);Copy=new JMenuItem(” 复制”);Paste=new JMenuItem(” 粘贴”);Delete=new JMenuItem(” 删除”);SelectAll=new JMenuItem(” 全选”);FindAndReplace=new JMenuItem(” 查找替换…”);Pane=new JScrollPane(this);Manager=new UndoManager();menu=new MenuList();find=new FindAndReplace(notepad);find.Dialog.setLocation(x,y);Undo.setEnabled(false);Redo.setEnabled(false);setLineWrap(true);setWrapStyleWord(true);Manager.setLimit(-1);Popup.add(Undo);Popup.add(Redo);Popup.addSeparator();Popup.add(Cut);Popup.add(Copy);Popup.add(Paste);Popup.add(Delete);Popup.addSeparator();Popup.add(SelectAll);Popup.add(FindAndReplace);add(Popup);menu.Edit.addMenuListener(this);menu.WordWrap.addItemListener(this);menu.Truncation.addItemListener(this);getDocument().addUndoableEditListener(this);addMouseListener(this);find.FindNext.addActionListener(this);find.Replace.addActionListener(this);find.ReplaceAll.addActionListener(this);find.Finish.addActionListener(this);}public void saveFile(){try {FileWriter fw = new FileWriter(Path+Name,false);BufferedWriter bw=new BufferedWriter(fw);bw.write(getText());bw.close();fw.close();Saved=true;} catch (IOException e){}}public void openFile(){try {int c;StringBuffer sb=new StringBuffer();FileReader fr=new FileReader(Path+Name);setText(null);while((c=fr.read())!=-1)sb.append((char)c);setText(sb.toString());Saved=true;fr.close();Undo.setEnabled(false);Redo.setEnabled(false);menu.Undo.setEnabled(false);menu.Redo.setEnabled(false);}catch (IOException e){}}public void delete(){int start=getSelectionStart();int end=getSelectionEnd();replaceRange(“”,start,end);}public int lastOf(String s1,int i){String s=getText();if(find.MatchCase.isSelected()) return s.lastIndexOf(s1,i);else{s=s.toLowerCase();return s.lastIndexOf(s1.toLowerCase(),i);}}public int nextOf(String s1,int i){String s=getText();if(find.MatchCase.isSelected()) return s.indexOf(s1,i);else{s=s.toLowerCase();return s.indexOf(s1.toLowerCase(),i);}}public void actionPerformed(ActionEvent e){Object obj=e.getSource();if(obj==find.Finish) find.Dialog.setVisible(false);String s1=find.FindText.getText();String s2=find.ReplaceText.getText();int len1=s1.length(),len2=s2.length();if(len1<1) return;int head=getSelectionStart(),rear=getSelectionEnd();if(obj==find.Replace){if(head<rear) replaceRange(s2,head,rear);else obj=find.FindNext;}if(obj==find.FindNext){if(find.Up.isSelected()){head=lastOf(s1,head-len1);if(head<0) return;select(head, head+len1);}else{rear=nextOf(s1, rear);if(rear<0) return;select(rear,rear+len1);}}else if(obj==find.ReplaceAll){rear=0;while(true){rear=nextOf(s1,rear);if(rear<0) return;replaceRange(s2,rear,rear+len1);rear=rear+len2;setCaretPosition(rear);}}}public void menuSelected(MenuEvent e){Clipboard Board=Toolkit.getDefaultToolkit().getSystemClipboard();Transferable contents = Board.getContents(Board);DataFlavor flavor = DataFlavor.stringFlavor;if(contents.isDataFlavorSupported(flavor))menu.Paste.setEnabled(true);elsemenu.Paste.setEnabled(false);if(getSelectedText()!=null){menu.Cut.setEnabled(true);menu.Copy.setEnabled(true);menu.Delete.setEnabled(true);}else{menu.Cut.setEnabled(false);menu.Copy.setEnabled(false);menu.Delete.setEnabled(false);}if(getText().isEmpty()){menu.SelectAll.setEnabled(false);menu.FindAndReplace.setEnabled(false);}else{menu.SelectAll.setEnabled(true);menu.FindAndReplace.setEnabled(true);}}public void undoableEditHappened(UndoableEditEvent e){Manager.addEdit(e.getEdit());Saved=false;menu.Undo.setEnabled(true);Undo.setEnabled(true);menu.Redo.setEnabled(false);Redo.setEnabled(false);}public void mouseReleased(MouseEvent e) {if(e.isPopupTrigger()){Clipboard Board=Toolkit.getDefaultToolkit().getSystemClipboard();Transferable contents = Board.getContents(Board);DataFlavor flavor = DataFlavor.stringFlavor;if(contents.isDataFlavorSupported(flavor))Paste.setEnabled(true);elsePaste.setEnabled(false);if(getSelectedText()!=null){Cut.setEnabled(true);Copy.setEnabled(true);Delete.setEnabled(true);}else{Cut.setEnabled(false);Copy.setEnabled(false);Delete.setEnabled(false);}if(getText().isEmpty()){SelectAll.setEnabled(false);FindAndReplace.setEnabled(false);}else{SelectAll.setEnabled(true);FindAndReplace.setEnabled(true);}Popup.show(this,e.getX(),e.getY());}}public void itemStateChanged(ItemEvent e) {if(e.getSource()==menu.WordWrap){setLineWrap(menu.WordWrap.isSelected());menu.Truncation.setEnabled(menu.WordWrap.isSelected());}elsesetWrapStyleWord(!menu.Truncation.isSelected());}public void mousePressed(MouseEvent e) {}public void mouseClicked(MouseEvent e) {}public void mouseEntered(MouseEvent e) {}public void mouseExited(MouseEvent e) {}public void menuCanceled(MenuEvent e) {}public void menuDeselected(MenuEvent e) {}}为你的难过而快乐的是敌人，
用Java编写的记事本–原创（转载请留言）
