1.实现所示用户界面

2.在三个文本框中输入，单击“保存”按钮时，将所有输入的信息保存到当前目录下名为me.txt的文件中。

3.单击“另存为”按钮时弹出保存对话框，可以自定义文件名、保存目录。

package Work1;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.awt.event.ActionListener;


import java.io.*;

public class win extends JFrame  {//implements ActionListener
    private BorderLayout bs;
    JPanel jp=new JPanel();
    JLabel wlstclass = new JLabel("班级");
    JTextField wtstclass =new JTextField();
    JLabel wlstnum = new JLabel("学号");
    JTextField wtstnum = new JTextField();
    JLabel wlstname = new JLabel("姓名");
    JTextField wtstname = new JTextField();
    Button wbsave = new Button("保存");
    Button wosave = new Button("另存为");
    public win(String s){
        super(s);
        this.setLayout(null);
        wlstclass.setBounds(new Rectangle(20,20,50,30));
        wtstclass.setBounds(new Rectangle(80,20,180,30));
        wlstnum.setBounds(new Rectangle(20,60,50,30));
        wtstnum.setBounds(new Rectangle(80,60,180,30));
        wlstname.setBounds(new Rectangle(20,100,50,30));
        wtstname.setBounds(new Rectangle(80,100,180,30));
        wbsave.setBounds(new Rectangle(0,140,300,20));
        wosave.setBounds(new Rectangle(0,160,300,20));
        this.add(wlstclass);
        this.add(wtstclass);
        this.add(wlstnum);
        this.add(wtstnum);
        this.add(wlstname);
        this.add(wtstname);
        this.add(wbsave);
        this.add(wosave);
         SimpleListener ourListener = new SimpleListener();
         // 建立一个actionlistener让多个个按钮共享
         wbsave.addActionListener(ourListener);
         wosave.addActionListener(ourListener);
        this.setSize(300,220);
        this.setVisible(true);
    }
    public static void main(String[] args){
        win w1 = new win("图形界面");
        w1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    class SimpleListener implements ActionListener{
        public void actionPerformed(ActionEvent e) {
            String buttonName = e.getActionCommand();
            if (buttonName.equals("保存")) {
                try {
                    String c = wtstclass.getText();
                    String name = wtstname.getText();
                    String num = wtstnum.getText();
                    String all = "班级：" +c+"学号："+num+ "姓名："+name+"\r\n";
                    File file = new File("d:/me.txt");
                    // 创建文件
                    file.createNewFile();
                    // creates a FileWriter Object
                    FileWriter writer = new FileWriter(file);
                    // 向文件写入内容
                    writer.write(all);
                    writer.flush();
                    writer.close();
                } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
            }
            if(buttonName.contentEquals("另存为")) {
                try {
                    String c = wtstclass.getText();
                    String name = wtstname.getText();
                    String num = wtstnum.getText();
                    String all = "班级：" +c+"学号："+num+ "姓名："+name+"\r\n";
                    String path="";
                    JFileChooser oths = new JFileChooser();
                    //oths.setSize(300,100);
                    oths.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
                    oths.showSaveDialog(jp);
                    path = oths.getSelectedFile().getAbsolutePath();
                    FileWriter writer=new FileWriter(path+".txt");
                    // 向文件写入内容
                    writer.write(all);
                    writer.flush();
                    writer.close();
                } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
            }
        }
    }
}