[置顶] 用Java GUI做一个简单的管理系统

1.先完成主页面MainUI（代码如下）

package com.pag_1;  
import javax.swing.*;  
import java.awt.*;  
import java.awt.event.ActionEvent;  
import java.awt.event.ActionListener;  

public class MainUI extends JFrame implements ActionListener {  

    //定义组件   
    JButton jb1,jb2,jb3=null;  
    JRadioButton jrb1,jrb2=null;  
    JPanel jp1,jp2,jp3,jp4=null;  
    JTextField jtf=null;  
    JLabel jlb1,jlb2,jlb3=null;  
    JPasswordField jpf=null;  
    ButtonGroup bg=null;  

    //设定用户名和密码  
    final String stu_name="王小明";  
    final String stu_pwd="1"; 
    final String stu_num="14140301"; 
    final String tea_name="王老师";  
    final String tea_pwd="1";  
    final String tea_num="00001"; 

    public static void main(String[] args) {  

        MainUI mUI=new MainUI();  
    }  
    public MainUI()  
    {  
         //创建组件  
        jb1=new JButton("登录");  
        jb2=new JButton("重置"); 
        jb3=new JButton("退出");

        //设置监听  
        jb1.addActionListener(this);  
        jb2.addActionListener(this);  
        jb3.addActionListener(this);  

        jrb1=new JRadioButton("教师");  
        jrb2=new JRadioButton("学生");  
        bg=new ButtonGroup();  
        bg.add(jrb1);  
        bg.add(jrb2);  
        jrb2.setSelected(true);  //初始页面默认选择权限为 学生

        jp1=new JPanel();  
        jp2=new JPanel();  
        jp3=new JPanel();  
        jp4=new JPanel();                 

        jlb1=new JLabel("用户名：");  
        jlb2=new JLabel("密    码：");  
        jlb3=new JLabel("权    限：");  

        jtf=new JTextField(10);  
        jpf=new JPasswordField(10);  
        //加入到JPanel中  
        jp1.add(jlb1);  
        jp1.add(jtf);  

        jp2.add(jlb2);  
        jp2.add(jpf);  

        jp3.add(jlb3);      //添加标签
        jp3.add(jrb1);  
        jp3.add(jrb2);  

        jp4.add(jb1);       //添加按钮
        jp4.add(jb2);  
        jp4.add(jb3);

        //加入JFrame中  
        this.add(jp1);  
        this.add(jp2);  
        this.add(jp3);  
        this.add(jp4);  

        this.setLayout(new GridLayout(4,1));            //选择GridLayout布局管理器        
        this.setTitle("学生成绩管理系统");          
        this.setSize(300,200);         
        this.setLocation(400, 200);           
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);    //设置当关闭窗口时，保证JVM也退出 
        this.setVisible(true);  
        this.setResizable(true);  

    }  

    public void actionPerformed(ActionEvent e) {            //事件判断

        if(e.getActionCommand()=="登录")  
        {  
            //如果选中教师登录  
            if(jrb1.isSelected())  
            {  
                  tealogin();                               //连接到教师的方法 页面
            }else if(jrb2.isSelected()) //学生在登录系统  
            {  
                  stulogin();                               //连接到学生的方法 页面
            }  

        }else if(e.getActionCommand()=="重置")  
        {  
                  clear();  
        }             

    }  

     //学生登录判断方法  
    public void stulogin()  
    {  
        if(stu_name.equals(jtf.getText())&&stu_pwd.equals(jpf.getText()))  
        {            
            JOptionPane.showMessageDialog(null,"登录成功！","提示消息",JOptionPane.WARNING_MESSAGE);           
            dispose();        
            clear();            
            StdUI ui=new StdUI();       //创建新界面  
        }else if(jtf.getText().isEmpty()&&jpf.getText().isEmpty())  
        {  
            JOptionPane.showMessageDialog(null,"请输入用户名和密码！","提示消息",JOptionPane.WARNING_MESSAGE);  
        }else if(jtf.getText().isEmpty())  
        {  
            JOptionPane.showMessageDialog(null,"请输入用户名！","提示消息",JOptionPane.WARNING_MESSAGE);  
        }else if(jpf.getText().isEmpty())  
        {  
            JOptionPane.showMessageDialog(null,"请输入密码！","提示消息",JOptionPane.WARNING_MESSAGE);  
        }else  
        {  
            JOptionPane.showMessageDialog(null,"用户名或者密码错误！
请重新输入","提示消息",JOptionPane.ERROR_MESSAGE);  
            //清空输入框  
            clear();  
        }  
    }  
    //教师登录判断方法  
    public void tealogin()  
    {  
        if(tea_name.equals(jtf.getText())&&tea_pwd.equals(jpf.getText()))  
        {  

             JOptionPane.showMessageDialog(null,"登录成功！","提示消息",JOptionPane.WARNING_MESSAGE);  
             clear();         
             dispose();             
             TerUI ui=new TerUI();  //创建一个新界面  
        }else if(jtf.getText().isEmpty()&&jpf.getText().isEmpty())  
        {  
            JOptionPane.showMessageDialog(null,"请输入用户名和密码！","提示消息",JOptionPane.WARNING_MESSAGE);  
        }else if(jtf.getText().isEmpty())  
        {  
            JOptionPane.showMessageDialog(null,"请输入用户名！","提示消息",JOptionPane.WARNING_MESSAGE);  
        }else if(jpf.getText().isEmpty())  
        {  
            JOptionPane.showMessageDialog(null,"请输入密码！","提示消息",JOptionPane.WARNING_MESSAGE);  
        }else  
        {  
            JOptionPane.showMessageDialog(null,"用户名或者密码错误！
请重新输入","提示消息",JOptionPane.ERROR_MESSAGE);  
            clear();  //清空输入框  
        }  
    }  
    //清空文本框和密码框  
    public  void clear()  
    {  
        jtf.setText("");  
        jpf.setText("");  
    }  

} 

用户名和密码如下：

2.完成学生界面StuUI，这个页面在MainUI界面设置了按钮连接（代码如下）

package com.pag_1;
import java.awt.*;  
import java.awt.event.*;  
import javax.swing.*;  
import javax.swing.JButton;
import java.awt.color.*;
import javax.swing.JOptionPane;
import com.pag_1.MainUI;  
public class StdUI extends JFrame implements ActionListener  
{  

         //定义组件  
        JButton jb1=new JButton();
        JButton jb2=new JButton(); 
        JPanel jp1,jp2,jp3,jp4=null;  
        JLabel jlb1,jlb2,jlb3,jlb4,jlb5,jlb6=null;  

        public static void main(String[] args)
        {  
          StdUI  ui=new StdUI();  
        }  


        //****************************事件判断**********************

        //构造函数  
        public  StdUI()    //不能申明为void!!!!!否则弹不出新界面  
        {  

            //创建组件  
            jb1=new JButton("课程表");  
            jb1.setForeground(Color.BLUE);
            jb2=new JButton("成绩查询");  
            jb2.setForeground(Color.BLUE);

            jp1=new JPanel();  
            jp2=new JPanel();  
            jp3=new JPanel();  

            jlb1=new JLabel("姓名：");  
            jlb2=new JLabel("学号：");  
            jlb3=new JLabel("最新公告："); 
            jlb3.setForeground(Color.red);
            jlb4=new JLabel("我院举行学生体测通知");  
            jlb5=new JLabel(new MainUI().stu_name);
            jlb6=new JLabel(new MainUI().stu_num);

            jp1.add(jlb1); 
            jp1.add(jlb5);
            jp1.add(jlb2);  
            jp1.add(jlb6);


            jp2.add(jb1);  
            jp2.add(jb2);  

            jp3.add(jlb3);
            jp3.add(jlb4); 

            this.add(jp1);  
            this.add(jp2);  
            this.add(jp3);  


            //设置布局管理器  
            this.setLayout(new GridLayout(4,3,50,50));  
            this.setTitle("学生成绩管理系统");  
            this.setSize(400,300);  
            this.setLocation(200, 200);       

            this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 

            this.setVisible(true); 
            jb1.addActionListener(this);
            jb2.addActionListener(this);


        }

        public void actionPerformed(ActionEvent e) {  
             if(e.getSource() == jb1){
                //关闭当前界面  
                 dispose();  
                 new KeChengBiaoUI();
                }else if(e.getSource() == jb2){
                    //关闭当前界面  
                    dispose();  
                    new ChengJiBiaoUI();
                }

        }  
} 

运行MainUI输入用户学生，会出现下面学生界面，其中界面中的 课程表和成绩查询是两个可以点击的按钮，会连接到下个页面再后面步骤。

3.完成教师界面TerUI，这个和学生页面一样，在MainUI页面有设置按钮事件，连接到MainUI页面.(代码如下)

package com.pag_1;
import java.awt.*;  
import java.awt.event.*;  
import javax.swing.*;  
import javax.swing.JButton;
import com.pag_1.MainUI;  
public class TerUI extends JFrame implements ActionListener  
{   
         //定义组件  
        JButton jb1,jb2=null;  
        JPanel jp1,jp2,jp3,jp4=null;  
        JLabel jlb1,jlb2,jlb3,jlb4,jlb5,jlb6=null;  

        public static void main(String[] args) {            
          TerUI  ui=new TerUI();  
        }    
        public  TerUI()  
        {  
            //创建组件  
            jb1=new JButton("课程管理");
            jb1.setForeground(Color.BLUE);
            jb2=new JButton("学生名单");  
            jb2.setForeground(Color.BLUE);

            jp1=new JPanel();  
            jp2=new JPanel();  
            jp3=new JPanel();  

            jlb1=new JLabel("姓名：");  
            jlb2=new JLabel("工号：");  
            jlb3=new JLabel("最新公告："); 
            jlb3.setForeground(Color.red);
            jlb4=new JLabel("我院举行体测的通知");  
            jlb5=new JLabel(new MainUI().tea_name);
            jlb6=new JLabel(new MainUI().tea_num);

            jp1.add(jlb1); 
            jp1.add(jlb5);
            jp1.add(jlb2);  
            jp1.add(jlb6);

            jp2.add(jb1);  
            jp2.add(jb2);  

            jp3.add(jlb3);
            jp3.add(jlb4); 

            this.add(jp1);  
            this.add(jp2);  
            this.add(jp3);          
            this.setLayout(new GridLayout(4,3,50,50));  //设置布局管理器  
            this.setTitle("学生成绩管理系统");  
            this.setSize(400,300);  
            this.setLocation(200, 200);       
            this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
            this.setVisible(true);            
            jb1.addActionListener(this);
            jb2.addActionListener(this);
}  
        public void actionPerformed(ActionEvent e) {  
             if(e.getSource() == jb1){              
                  dispose();  
                  new KeChengGuanLiUI();                //创建一个新界面  
                }else if(e.getSource() == jb2){
                  dispose();  
                  new XueShengMingDanUI();              //创建一个新界面  
                }

        }  
} 

运行MainUI输入用户教师，会出现下面教师界面，其中界面中的 课程管理和学生名单是两个可以点击的按钮，会连接到下个页面再后面步骤。

4.完成学生界面的课程表界面（代码如下）

package com.pag_1;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.TableColumn;

public class KeChengBiaoUI extends JFrame  
{  

    public KeChengBiaoUI()  
    {  
        intiComponent();  
    }  

    private void intiComponent()  
    {        
        String[] columnNames =  
        { "课节数","星期一", "星期二", "星期三", "星期四", "星期五", "星期六","星期日" };  

        Object[][] obj=new Object[8][8];  
        for (int i=0;i<8;i++)  
        {  
            for(int j=0;j<8;j++)  
            {  
                switch (j)  
                {  
                case 0:  
                    obj[0][0] = "第一节课";
                    obj[0][1] = "光纤通信"; 
                    obj[0][2] = "电磁场"; 
                    obj[0][3] = "物联网"; 
                    obj[0][4] = "DSP实验"; 
                    obj[0][5] = " "; 
                    obj[0][6] = "手机维修"; 
                    obj[0][7] = " "; 
                    break;  
                case 1:  
                    obj[1][0] = "第二节课";
                    obj[1][1] = "光纤通信"; 
                    obj[1][2] = "电磁场"; 
                    obj[1][3] = "物联网"; 
                    obj[1][4] = "DSP实验"; 
                    obj[1][5] = " "; 
                    obj[1][6] = "手机维修"; 
                    obj[1][7] = " ";  
                    break;  
                case 2:  
                    obj[2][0] = "第三节课";
                    obj[2][1] = "Android"; 
                    obj[2][2] = " "; 
                    obj[2][3] = " "; 
                    obj[2][4] = "DSP实验"; 
                    obj[2][5] = "手机维修"; 
                    obj[2][6] = "手机维修"; 
                    obj[2][7] = " ";   
                    break;  
                case 3:  
                    obj[3][0] = "第四节课";
                    obj[3][1] = "Android"; 
                    obj[3][2] = " "; 
                    obj[3][3] = " "; 
                    obj[3][4] = " "; 
                    obj[3][5] = "手机维修"; 
                    obj[3][6] = "手机维修"; 
                    obj[3][7] = "光纤通信";   
                    break;  
                case 4:  
                    obj[4][0] = "第五节课";
                    obj[4][1] = "Android实验"; 
                    obj[4][2] = " "; 
                    obj[4][3] = " "; 
                    obj[4][4] = " "; 
                    obj[4][5] = " "; 
                    obj[4][6] = " "; 
                    obj[4][7] = " ";  
                    break;  
                case 5:  
                    obj[5][0] = "第六节课";
                    obj[5][1] = "Android实验"; 
                    obj[5][2] = " "; 
                    obj[5][3] = " "; 
                    obj[5][4] = " "; 
                    obj[5][5] = " "; 
                    obj[5][6] = " "; 
                    obj[5][7] = " ";   
                    break;  
                case 6:  
                    obj[6][0] = "第七节课";
                    obj[6][1] = "Android实验"; 
                    obj[6][2] = " "; 
                    obj[6][3] = " "; 
                    obj[6][4] = " "; 
                    obj[6][5] = " "; 
                    obj[6][6] = " "; 
                    obj[6][7] = " ";   
                    break;  
                case 7:  
                    obj[7][0] = "第七节课";
                    obj[7][1] = ""; 
                    obj[7][2] = " "; 
                    obj[7][3] = " "; 
                    obj[7][4] = " "; 
                    obj[7][5] = " "; 
                    obj[7][6] = " "; 
                    obj[7][7] = " ";   
                    break;  
                case 8:  
                    obj[8][0] = "第八节课";
                    obj[8][1] = " "; 
                    obj[8][2] = " "; 
                    obj[8][3] = " "; 
                    obj[8][4] = " "; 
                    obj[8][5] = " "; 
                    obj[8][6] = " "; 
                    obj[8][7] = " ";   
                    break;  
                }  
            }  
        }  

        JTable table=new JTable(obj, columnNames);        
        TableColumn column=null;  
        int colunms = table.getColumnCount();  
        for(int i=0;i<colunms;i++)  
        {  
            column = table.getColumnModel().getColumn(i);             
            column.setPreferredWidth(100);  
        }        
        table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);      
        JScrollPane scroll = new JScrollPane(table);  
        scroll.setSize(300, 50);  

        add(scroll); 

        this.setLocation(450, 200); 
        this.setVisible(true);  
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
        this.pack();  
    }  

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

5.完成学生的成绩查询界面（代码如下）

package com.pag_1;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.TableColumn;

public class ChengJiBiaoUI extends JFrame  
{  

    public ChengJiBiaoUI()  
    {  
        intiComponent();  
    }  

    //初始化窗体组件  
    private void intiComponent()  
    {  

        String[] columnNames =  
        { "课程数目","课程名称", "学分", "绩点", "分数", "补考" };  //设置JTable的列名 
        Object[][] obj=new Object[7][7];  
        for (int i=0;i<7;i++)  
        {  
            for(int j=0;j<7;j++)  
            {  
                switch (j)  
                {  
                case 0:  
                    obj[0][0] = "              1";
                    obj[0][1] = "          光纤通信"; 
                    obj[0][2] = "              2"; 
                    obj[0][3] = "             1.5"; 
                    obj[0][4] = "              75"; 
                    obj[0][5] = "              否"; 


                    break;  
                case 1:  
                    obj[1][0] = "              2";
                    obj[1][1] = "          Android"; 
                    obj[1][2] = "              2"; 
                    obj[1][3] = "             1.8"; 
                    obj[1][4] = "              5"; 
                    obj[1][5] = "              否"; 

                    break;  
                case 2:  
                    obj[2][0] = "              3";
                    obj[2][1] = "          物联网"; 
                    obj[2][2] = "              1.5"; 
                    obj[2][3] = "             1.2"; 
                    obj[2][4] = "              70"; 
                    obj[2][5] = "              否"; 

                    break;  
                case 3:  
                    obj[3][0] = "              4";
                    obj[3][1] = "          电磁场"; 
                    obj[3][2] = "              2"; 
                    obj[3][3] = "             1.6"; 
                    obj[3][4] = "              78"; 
                    obj[3][5] = "              否"; 

                    break;  
                case 4:  
                    obj[4][0] = "              5";
                    obj[4][1] = "         手机维修"; 
                    obj[4][2] = "              1.0"; 
                    obj[4][3] = "             1.0"; 
                    obj[4][4] = "              优秀"; 
                    obj[4][5] = "              否"; 

                    break;  
                case 5:  
                    obj[5][0] = "              6";
                    obj[5][1] = "             DSP"; 
                    obj[5][2] = "             1.0"; 
                    obj[5][3] = "             1.0"; 
                    obj[5][4] = "              良好"; 
                    obj[5][5] = "              否"; 
                    break;  
                case 6:  
                    obj[6][0] = "              7";
                    obj[6][1] = "       通信原理实验"; 
                    obj[6][2] = "             1.0"; 
                    obj[6][3] = "             1.0"; 
                    obj[6][4] = "              良好"; 
                    obj[6][5] = "              否"; 
                    break;  

                }  
            }  
        }  

        JTable table=new JTable(obj, columnNames);  //JTable的其中一种构造方法 
        TableColumn column=null;                    //设置JTable的列默认的宽度和高度 
        int colunms = table.getColumnCount();  
        for(int i=0;i<colunms;i++)  
        {  
            column = table.getColumnModel().getColumn(i);  
            column.setPreferredWidth(100);          //将每一列的默认宽度设置为100
        }  
        table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF); //设置JTable自动调整列表的状态，此处设置为关闭  
        JScrollPane scroll = new JScrollPane(table);  //用JScrollPane装载JTable，这样超出范围的列就可以通过滚动条来查看
        scroll.setSize(300, 50);  

        add(scroll); 

        this.setLocation(450, 200); 
        this.setVisible(true);  
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
        this.pack();  
    }  

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

6.完成教师的课程管理界面（代码如下）

package com.pag_1;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.TableColumn;

public class KeChengGuanLiUI extends JFrame  
{   
    public KeChengGuanLiUI()  
    {  
        intiComponent();  
    }    
    private void intiComponent()  
    {         
        String[] columnNames =  
        { "课节数","星期一", "星期二", "星期三", "星期四", "星期五", "星期六","星期日" };           
        Object[][] obj=new Object[8][8];  
        for (int i=0;i<8;i++)  
        {  
            for(int j=0;j<8;j++)  
            {  
                switch (j)  
                {  
                case 0:  
                    obj[0][0] = "  第一节课";
                    obj[0][1] = "      有课"; 
                    obj[0][2] = " "; 
                    obj[0][3] = " "; 
                    obj[0][4] = "      有课"; 
                    obj[0][5] = " "; 
                    obj[0][6] = ""; 
                    obj[0][7] = " "; 
                    break;  
                case 1:  
                    obj[1][0] = "  第二节课";
                    obj[1][1] = "      有课"; 
                    obj[1][2] = ""; 
                    obj[1][3] = ""; 
                    obj[1][4] = "      有课"; 
                    obj[1][5] = " "; 
                    obj[1][6] = ""; 
                    obj[1][7] = " ";  
                    break;  
                case 2:  
                    obj[2][0] = "  第三节课";
                    obj[2][1] = ""; 
                    obj[2][2] = " "; 
                    obj[2][3] = "     有课"; 
                    obj[2][4] = ""; 
                    obj[2][5] = ""; 
                    obj[2][6] = ""; 
                    obj[2][7] = " ";   
                    break;  
                case 3:  
                    obj[3][0] ="  第四节课";
                    obj[3][1] = ""; 
                    obj[3][2] = " "; 
                    obj[3][3] = "     有课"; 
                    obj[3][4] = " "; 
                    obj[3][5] = ""; 
                    obj[3][6] = ""; 
                    obj[3][7] = "";   
                    break;  
                case 4:  
                    obj[4][0] ="  第五节课";
                    obj[4][1] = ""; 
                    obj[4][2] = " "; 
                    obj[4][3] = " "; 
                    obj[4][4] = " "; 
                    obj[4][5] = " "; 
                    obj[4][6] = " "; 
                    obj[4][7] = " ";  
                    break;  
                case 5:  
                    obj[5][0] ="  第六节课";
                    obj[5][1] = ""; 
                    obj[5][2] = "   开会"; 
                    obj[5][3] = " "; 
                    obj[5][4] = " "; 
                    obj[5][5] = " "; 
                    obj[5][6] = " "; 
                    obj[5][7] = " ";   
                    break;  
                case 6:  
                    obj[6][0] ="  第七节课";
                    obj[6][1] = ""; 
                    obj[6][2] = "  有课"; 
                    obj[6][3] = " "; 
                    obj[6][4] = "    开会"; 
                    obj[6][5] = " "; 
                    obj[6][6] = " "; 
                    obj[6][7] = " ";   
                    break;  
                case 7:  
                    obj[7][0] ="  第八节课";
                    obj[7][1] = ""; 
                    obj[7][2] = "  有课 "; 
                    obj[7][3] = " "; 
                    obj[7][4] = " "; 
                    obj[7][5] = " "; 
                    obj[7][6] = " "; 
                    obj[7][7] = " ";   
                    break;   
                }  
            }  
        }          

        JTable table=new JTable(obj, columnNames);   
        TableColumn column=null;  
        int colunms = table.getColumnCount();  
        for(int i=0;i<colunms;i++)  
        {  
            column = table.getColumnModel().getColumn(i);             
            column.setPreferredWidth(100);  
        }         
        table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);        
        JScrollPane scroll = new JScrollPane(table);  
        scroll.setSize(300, 50);  

        add(scroll); 

        this.setLocation(450, 200); 
        this.setVisible(true);  
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
        this.pack();  
    }  

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

7.完成教师页面的学生名单页面（代码如下）

package com.pag_1;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.TableColumn;

public class XueShengMingDanUI extends JFrame  
{  

    public XueShengMingDanUI()  
    {  
        intiComponent();  
    }  

     //初始化窗体组件 
    private void intiComponent()  
    {  
        // 设置JTable的列名   
        String[] columnNames =  
        { "学号","姓名",  "专业", "班级"};  
        Object[][] obj=new Object[7][7];  
        for (int i=0;i<7;i++)  
        {  
            for(int j=0;j<7;j++)  
            {  
                switch (j)  
                {  
                case 0:  
                    obj[0][0] = "       14140301";
                    obj[0][1] = "               王小明"; 
                    obj[0][2] = "         通信工程"; 
                    obj[0][3] = "                    2";    
                    break;  
                case 1:  
                    obj[1][0] = "       14140302";
                    obj[1][1] = "            王雷"; 
                    obj[1][2] = "         通信工程"; 
                    obj[1][3] = "                    2"; 
                    break;  
                case 2:  
                    obj[2][0] = "       14140303";
                    obj[2][1] = "            李芳"; 
                    obj[2][2] = "         通信工程"; 
                    obj[2][3] = "                    2"; 
                    break;  
                case 3:  
                    obj[3][0] = "       14140304";
                    obj[3][1] = "            张三"; 
                    obj[3][2] = "         通信工程"; 
                    obj[3][3] = "                    2";                  
                    break;  
                case 4:  
                    obj[4][0] = "       14140305";
                    obj[4][1] = "            李四"; 
                    obj[4][2] = "         通信工程"; 
                    obj[4][3] = "                    2"; 
                    break;  
                case 5:  
                    obj[5][0] = "       14140306";
                    obj[5][1] = "            文宇"; 
                    obj[5][2] = "         通信工程"; 
                    obj[5][3] = "             2"; 
                    break;  
                case 6:  
                    obj[6][0] = "       14140307";
                    obj[6][1] = "            王飞"; 
                    obj[6][2] = "         通信工程"; 
                    obj[6][3] = "                    2";                 
                    break;  

                }  
            }  
        }  

        JTable table=new JTable(obj, columnNames);  //JTable的其中一种构造方法 
        TableColumn column=null;                    //设置JTable的列默认的宽度和高度 
        int colunms = table.getColumnCount();  
        for(int i=0;i<colunms;i++)  
        {  
            column = table.getColumnModel().getColumn(i);  
            column.setPreferredWidth(100);           //将每一列的默认宽度设置为100
        }   
        table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);  //设置JTable自动调整列表的状态，此处设置为关闭                 
        JScrollPane scroll = new JScrollPane(table);  //用JScrollPane装载JTable，这样超出范围的列就可以通过滚动条来查看 
        scroll.setSize(300, 50);         

        add(scroll); 

        this.setLocation(450, 200); 
        this.setVisible(true);  
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
        this.pack();  
    }  

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