FileDialog对话框对文件操作

import java.awt.FileDialog;import java.awt.FlowLayout;import java.awt.Menu;import java.awt.MenuBar;import java.awt.MenuItem;import java.awt.TextArea;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.File;import java.io.FileNotFoundException;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import javax.swing.JFrame;public class FileDialogs extends JFrame{Menu menu;MenuBar mbar;MenuItem open,load;File file;FileReader fread;BufferedReader breader;FileWriter fwiter;BufferedWriter bwiter;TextArea area;FileDialog log_save,log_open;FileDialogs(){menu=new Menu("对话框");mbar=new MenuBar();load=new MenuItem("load");open=new MenuItem("open");menu.add(load);menu.add(open);mbar.add(menu);log_save=new FileDialog(this, "保存文件对话框",FileDialog.SAVE);log_open=new FileDialog(this,"打开文件对话框",FileDialog.LOAD);setMenuBar(mbar);setBounds(100,100,500,500);setLayout(new FlowLayout());setVisible(true);validate();area=new TextArea();add(area);log_save.addWindowListener(new WindowAdapter(){@Overridepublic void windowClosing(WindowEvent arg0) {// TODO Auto-generated method stublog_save.setVisible(false);super.windowClosing(arg0);}});log_open.addWindowListener(new WindowAdapter(){@Overridepublic void windowClosing(WindowEvent e) {// TODO Auto-generated method stublog_open.setVisible(false);super.windowClosing(e);}});open.addActionListener(new ActionListener(){@Overridepublic void actionPerformed(ActionEvent arg0) {// TODO Auto-generated method stublog_open.setVisible(true);area.setText(null);String s=null;if(log_open.getFile()!=null){File file=new File(log_open.getDirectory(),log_open.getFile());try {fread=new FileReader(file);breader=new BufferedReader(fread);while((s=breader.readLine())!=null){area.append(s+"\n");}breader.close();fread.close();} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}});load.addActionListener(new ActionListener(){@Overridepublic void actionPerformed(ActionEvent arg0) {// TODO Auto-generated method stublog_save.setVisible(true);String s=null;File file = new File(log_save.getDirectory(),log_save.getFile());try {fwiter=new FileWriter(file);bwiter=new BufferedWriter(fwiter);s=area.getText();bwiter.write(area.getText(),0,(area.getText().length()));bwiter.close();fwiter.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}});}}