Java实训——学生信息管理系统（菜鸟版）

标题## 零、绪论

菜鸟一只，初次做实训，说实话做的不咋地！以此文为纪念，希望在不久的将来实现那遥不可及的梦想！

一、代码

DenLu.java

package studentmanage;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Enumeration;

import javax.swing.*;


public class DenLu extends JFrame {
	public static void main(String[] args) {
		new DenLu();
	}
	
	JLabel label;
	JLabel userNum,userPwd;
	JLabel user;
	JTextField numField;
	JPasswordField pwdField;
	JButton button1,button2;      //登录  修改密码
	JRadioButton btn1,btn2,btn3;  //身份  管理员  教师  学生
	JPanel panel0,panel1,panel2,panel3,panel4;  //即作为容器，又做为组件
	JPanel panel;
	ButtonGroup btngp;
	
    public DenLu()  {
    	Dimension screenSize=Toolkit.getDefaultToolkit().getScreenSize();
	    setBounds((screenSize.width-800)/2,(screenSize.height-600)/2,800,600);
		
        label=new JLabel("学生信息管理系统",JLabel.CENTER);
        label.setFont(new Font("黑体", Font.PLAIN, 40));
        
		userNum=new JLabel("账号",JLabel.CENTER);
		userNum.setFont(new Font("宋体", Font.PLAIN, 20));
		
		userPwd=new JLabel("密码",JLabel.CENTER);
		userPwd.setFont(new Font("宋体", Font.PLAIN, 20));
		
		user=new JLabel("用户身份",JLabel.CENTER);
		user.setFont(new Font("宋体", Font.PLAIN, 20));
		
		button1=new JButton("登录");
		button1.setFont(new Font("宋体", Font.PLAIN, 20));
		button1.setBackground(Color.WHITE);
		
		button2=new JButton("修改密码");
		button2.setFont(new Font("宋体", Font.PLAIN, 20));
		button2.setBackground(Color.WHITE);
		
		btn1=new JRadioButton("管理员");
		btn1.setFont(new Font("宋体", Font.PLAIN, 15));
		btn1.setBackground(Color.WHITE);
		
		btn2=new JRadioButton("教师");
		btn2.setFont(new Font("宋体", Font.PLAIN, 15));
		btn2.setBackground(Color.WHITE);
		
		btn3=new JRadioButton("学生");
		btn3.setFont(new Font("宋体", Font.PLAIN, 15));
		btn3.setBackground(Color.WHITE);
		btngp=new ButtonGroup();
		
		btngp.add(btn1);
		btngp.add(btn2);
		btngp.add(btn3);

		button1.addActionListener(new Button1ActionListener());
		button2.addActionListener(new Button2ActionListener());
		
		numField=new JTextField(25);
		pwdField=new JPasswordField(25);
		panel0=new JPanel();
		panel1=new JPanel();
		panel2=new JPanel();
		panel3=new JPanel();
		panel4=new JPanel();
		
		panel0.setBackground(Color.decode("#A9A9A9"));
		panel1.setBackground(Color.decode("#A9A9A9"));
		panel2.setBackground(Color.decode("#A9A9A9"));
		panel3.setBackground(Color.decode("#A9A9A9"));
		panel4.setBackground(Color.decode("#A9A9A9"));
		
		panel=new JPanel();
		add(panel);
		
		panel0.add(label);
			
		panel1.add(userNum);
		panel1.add(numField);
		
		panel2.add(userPwd);
		panel2.add(pwdField);
		
		panel3.add(user);
		panel3.add(btn1);
		panel3.add(btn2);
		panel3.add(btn3);
	
		panel4.add(button1);
		panel4.add(button2);
		
		panel.add(panel0);
		panel.add(panel1);
		panel.add(panel2);
		panel.add(panel3);
		panel.add(panel4);
		
		panel.setLayout(new GridLayout(5,1,0,0));  //网格布局
		
		setTitle("登录界面");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
			
}
    class Button1ActionListener implements ActionListener{
    	public void actionPerformed(ActionEvent e) {
	        String num,pwd,user = null; 
	        
	        num=numField.getText();  
	        pwd=pwdField.getText(); 
	        if(btn1.isSelected()) {
	        	user=btn1.getText();
	        }else if(btn2.isSelected()) {
	        	user=btn2.getText();
	        }else if(btn3.isSelected()) {
	        	user=btn3.getText();
	        }
	        
	        
	        try{  
	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); //加载数据库驱动 
	           
	        }  
	        catch(ClassNotFoundException ex){  
	        System.out.println(ex);  
	        }  
	        try{  
	            Connection con;  
	            Statement sql;  
	            ResultSet rs;  
	            String url,userName,userPwd;  
	             // 连接数据库的语句
	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
	            userName="sa";  
	            userPwd="123";  
	            con=DriverManager.getConnection(url,userName,userPwd);  
	            sql=con.createStatement();  
	            rs=sql.executeQuery("select * from 用户信息表  where 账号 ='"+num+"' and 密码='"+pwd+"' and 用户='"+user+"'"); 
	            int q=0;  
	            while(rs.next()){  
	                q++;  
	            }  
	            if(q>0){ 
	            	
	            	JOptionPane.showMessageDialog(null, "登陆成功！","消息对话框",JOptionPane.WARNING_MESSAGE);  
	                dispose(); 
	                if(user=="管理员") {
	                	new Admin_UI();
	                }else if(user=="教师") {
	                	new Teach_UI();
	                }else if(user=="学生") {
	                	new Stud_UI(numField);
	                }
	                   
	                  
	            }  
	            else  
	                JOptionPane.showMessageDialog(null, "账号、密码、身份选择错误!","消息对话框",JOptionPane.WARNING_MESSAGE);  
	        }  
	        catch(SQLException exp){  
	            System.out.println(exp);  
	        } 
    		
    	}
    }
    
    class Button2ActionListener implements ActionListener{
    	public void actionPerformed(ActionEvent e) {
    		
        String num,pwd,user = null; 
        
        num=numField.getText();  
        pwd=pwdField.getText(); 
        if(btn1.isSelected()) {
        	user=btn1.getText();
        }else if(btn2.isSelected()) {
        	user=btn2.getText();
        }else if(btn3.isSelected()) {
        	user=btn3.getText();
        }
        
        
        try{  
          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); //加载数据库驱动 
           
        }  
        catch(ClassNotFoundException ex){  
        System.out.println(ex);  
        }  
        try{  
            Connection con;  
            Statement sql;  
            ResultSet rs;  
            String url,userName,userPwd;  
             // 连接数据库的语句
            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
            userName="sa";  
            userPwd="123";  
            con=DriverManager.getConnection(url,userName,userPwd);  
            sql=con.createStatement();  
            rs=sql.executeQuery("select * from 用户信息表  where 账号 ='"+num+"' and 密码='"+pwd+"' and 用户='"+user+"'"); 
            int q=0;  
            while(rs.next()){  
                q++;  
            }  
            if(q>0){ 
            	
            	JOptionPane.showMessageDialog(null, "您有权利修改密码","消息对话框",JOptionPane.WARNING_MESSAGE);  
                dispose();  
                new UpPsw();    
                  
            }  
            else  
                JOptionPane.showMessageDialog(null, "账号、密码、身份选择错误不可修改密码!","消息对话框",JOptionPane.WARNING_MESSAGE);  
        }  
        catch(SQLException exp){  
            System.out.println(exp);  
        } 
		  		
    	}
    	
    }

	
}

Admin_UI.java

package studentmanage;

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.table.DefaultTableModel;

import studentmanage.UpPsw.BtnActionListener;

public class Admin_UI extends JFrame{
	
	
	CardLayout cardLayout=new CardLayout();
	CardLayout card=new CardLayout();
	
	JMenuBar menubar=new JMenuBar();
	JMenu menu=new JMenu("管理员权限↓");
	
	JMenuItem item1=new JMenuItem("录入学生信息");
	JMenuItem item2=new JMenuItem("删除学生信息");
	JMenuItem item3=new JMenuItem("查找学生信息");
	JMenuItem item4=new JMenuItem("修改学生信息");
	
	JPanel panel1=new JPanel();
	JPanel panel1B=new JPanel();
	JPanel panel1C=new JPanel();
	JPanel panel2=new JPanel();
	JPanel panel2B=new JPanel();
	JPanel panel2C=new JPanel();
	JPanel panel3=new JPanel();
	JPanel panel3B=new JPanel();
	JPanel panel3C=new JPanel();
	JPanel panel4=new JPanel();
	JPanel panel4B=new JPanel();
	JPanel panel4C=new JPanel();
	JPanel panel=new JPanel();
	JPanel panel5=new JPanel();
	JPanel panel6=new JPanel();
	JPanel p=new JPanel();
	JPanel p0=new JPanel();
    JPanel p1=new JPanel();
	JPanel p2=new JPanel();
	JPanel p3=new JPanel();
	JPanel p4=new JPanel();

	JLabel userNum=new JLabel("学生学号");
	JLabel userName=new JLabel("学生姓名");
	JTextField numField=new JTextField(15);
	JTextField nameField=new JTextField(15);
	
	JButton btn1=new JButton("提交");
	JButton btn2=new JButton("删除");
	JButton btn3=new JButton("查询");
	JButton btn4=new JButton("修改");
	JButton btn5=new JButton("确认修改");
	
	String[] columnName= {"属性","信息"};
	String[][] data= {
			{"学号",""},{"姓名",""},{"性别",""},{"班级",""},{"出生年月",""},{"家庭地址",""},{"院系",""},{"入学时间",""}};
	
	
	JTable table1,table2;
	
	JScrollPane ScrollPane = new JScrollPane();
	
	
	

	public Admin_UI() {	
		
		table1=new JTable(data,columnName);
		
		
		Dimension screenSize=Toolkit.getDefaultToolkit().getScreenSize();
	    setBounds((screenSize.width-800)/2,(screenSize.height-600)/2,800,600);
		
		setTitle("学生信息管理系统——管理员");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
		
		menu.add(item1);
		menu.add(item2);
		menu.add(item3);
		menu.add(item4);
		
		menubar.add(menu);
		this.setJMenuBar(menubar);
		
		panel.setLayout(cardLayout);
		
		panel.add(panel1,"1");
		panel.add(panel2,"2");
		panel.add(panel3,"3");
		panel.add(panel4,"4");
		panel.add(panel5,"5");
		panel.add(panel6,"6");
		
		panel.setBackground(Color.decode("#A9A9A9"));
		panel1.setBackground(Color.decode("#A9A9A9"));
		panel2.setBackground(Color.decode("#A9A9A9"));
		panel2B.setBackground(Color.decode("#A9A9A9"));
		panel2C.setBackground(Color.decode("#A9A9A9"));
		panel3.setBackground(Color.decode("#A9A9A9"));
		panel3B.setBackground(Color.decode("#A9A9A9"));
		panel3C.setBackground(Color.decode("#A9A9A9"));
		panel4.setBackground(Color.decode("#A9A9A9"));
		panel4B.setBackground(Color.decode("#A9A9A9"));
		panel4C.setBackground(Color.decode("#A9A9A9"));
		panel5.setBackground(Color.decode("#A9A9A9"));
		panel6.setBackground(Color.decode("#A9A9A9"));
		p.setBackground(Color.decode("#A9A9A9"));
		p0.setBackground(Color.decode("#A9A9A9"));
		p1.setBackground(Color.decode("#A9A9A9"));
		p2.setBackground(Color.decode("#A9A9A9"));
		p3.setBackground(Color.decode("#A9A9A9"));
		p4.setBackground(Color.decode("#A9A9A9"));
		
		
		add(panel);
		
		item1.addActionListener(new Item1ActionListener());
		item2.addActionListener(new Item2ActionListener());
		item3.addActionListener(new Item3ActionListener());
		item4.addActionListener(new Item4ActionListener());	
			
	}
	
	//录入学生信息   成功
	class Item1ActionListener implements ActionListener{
		public void actionPerformed(ActionEvent e) {
			

			table1.setRowHeight(60);
			table1.getColumnModel().getColumn(0).setPreferredWidth(250);
			table1.getColumnModel().getColumn(1).setPreferredWidth(250);
			
		   
	        ScrollPane.setViewportView(table1);
	        
			
			panel1B.add(ScrollPane,BorderLayout.CENTER);
	        panel1C.add(btn1);
	        panel1B.setBackground(Color.decode("#A9A9A9"));
	        panel1C.setBackground(Color.decode("#A9A9A9"));
	        
	        BorderLayout borderLayout=new BorderLayout();
	        panel1.setLayout(borderLayout);
	   
	        panel1.add(panel1B,BorderLayout.CENTER);
	        panel1.add(panel1C,BorderLayout.SOUTH);
	        
	     
	        cardLayout.first(panel);
	        btn1.addActionListener(new ActionListener() {
	        	public void actionPerformed(ActionEvent e) {
	        		String data[]=new String[8];
	        		    	    	        
	    	        try{  
	    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); //加载数据库驱动 
	    	           
	    	        }  
	    	        catch(ClassNotFoundException ex){  
	    	        System.out.println(ex);  
	    	        }  
	    	        try{  
	    	            Connection con;  
	    	            String sql; 
	    	            PreparedStatement pst;
	    	            ResultSet rs;  
	    	            String url,userName,userPwd;  
	    	             // 连接数据库的语句
	    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
	    	            userName="sa";  
	    	            userPwd="123";  
	    	            con=DriverManager.getConnection(url,userName,userPwd);  
	    	            sql="insert into 学生个人档案信息(学号,姓名,性别,班级,出生年月,家庭地址,院系,入学时间)  values(?,?,?,?,?,?,?,?) "; 
	    	            pst = con.prepareStatement(sql,Statement.RETURN_GENERATED_KEYS);    	            
	    	            
	    	            for(int i=0;i<8;i++) {
		        			data[i]=table1.getValueAt(i,1).toString();	        			
		        		}
	    	            
	    	            for(int i=0;i<8;i++) {
	    	            	if(data[i].equals("")) {
	    	            		JOptionPane.showMessageDialog(null, "录入信息不完整无法提交！","消息对话框",JOptionPane.WARNING_MESSAGE);
	    	            		break;
	    	            	}    			
		        		}
	    	            
	    	            for(int i=0;i<8;i++) {
	    	            	pst.setString(i+1,data[i]);    			
		        		}
	    	            pst.executeUpdate(); 	    	            	            
	    	            pst.close();
	    	            //con.close();
	    	            JOptionPane.showMessageDialog(null, "录入信息成功！","消息对话框",JOptionPane.WARNING_MESSAGE);  
    	                dispose(); 
	    	        }
	    	          catch(SQLException exp){  
	    	            System.out.println(exp);  
	    	        } 
	    	            	      		
	        	}	        					
           });
        }
	}
		
	
	//删除学生信息  有问题
	class Item2ActionListener  implements ActionListener{
		public void actionPerformed(ActionEvent e) {
			
			
			
			
			p1.add(userNum);
			p1.add(numField);
			p2.add(userName);
			p2.add(nameField);
			p.add(p1);
			p.add(p2);
			p.setLayout((new GridLayout(2,1,0,100)));
			
			panel2B.add(p,BorderLayout.CENTER);
	        panel2C.add(btn2);
	     
	        panel2.add(panel2B);
	        panel2.add(panel2C);
	        panel2.setLayout(new GridLayout(2,1,0,100));     
	        
	        cardLayout.show(panel,"2");     
	        
	        btn2.addActionListener(new ActionListener() {
	        	public void actionPerformed(ActionEvent e) {
	        		String num,name;
	        		num=numField.getText();  
	        		name=nameField.getText(); 
	        			        		
	    	        try{  
	    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); //加载数据库驱动 
	    	           
	    	        }  
	    	        catch(ClassNotFoundException ex){  
	    	        System.out.println(ex);  
	    	        } 
	    	        
	    	        
	    	        try{  
	    	            Connection con;  
	    	            String sql; 
	    	            PreparedStatement pst;
	    	            ResultSet rs;  
	    	            String url,userName,userPwd;  
	    	             // 连接数据库的语句
	    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
	    	            userName="sa";  
	    	            userPwd="123";  
	    	            con=DriverManager.getConnection(url,userName,userPwd);  
	    	            sql="delete from 学生个人档案信息 where 学号 ='"+num+"' and 姓名='"+name+"'"; 
	    	            pst = con.prepareStatement(sql);    	            
	    	            int t=pst.executeUpdate(); 
	    	            if(t>0) {
	    	            	JOptionPane.showMessageDialog(null, "已删除该学生信息！","消息对话框",JOptionPane.WARNING_MESSAGE);  
	    	            }else {
	    	            	JOptionPane.showMessageDialog(null, "删除该学生信息失败！","消息对话框",JOptionPane.WARNING_MESSAGE); 
	    	            }

	    	            con.close();
	    	            
    	                dispose(); 
	    	        }
	    	          catch(SQLException exp){  
	    	            System.out.println(exp);  
	    	        } 
	    	            	      		
	        	}	        					
           });			
		}
	}
	

    //查询学生信息  失败
	class Item3ActionListener implements ActionListener{
		public void actionPerformed(ActionEvent e) {
			

			p3.add(userNum);
			p3.add(numField);
			
			panel3B.add(p3,BorderLayout.CENTER);
	        panel3C.add(btn3);
	     
	        panel3.add(panel3B);
	        panel3.add(panel3C);
	        panel3.setLayout(new GridLayout(2,1,0,100));	  
     
	        cardLayout.show(panel,"3");    
	        
	        btn3.addActionListener(new ActionListener() {
	        	public void actionPerformed(ActionEvent e) {
	        		String num;
	        		String xh = null,xm = null,xb= null,bj= null,csny= null,yx= null,rxsj= null,jtdz= null;
	        		
	        		num=numField.getText(); 
	    	        try{  
	    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); //加载数据库驱动 
	    	           
	    	        }  
	    	        catch(ClassNotFoundException ex){  
	    	        System.out.println(ex);  
	    	        }     	        
	    	        try{  
	    	            Connection con;  
	    	            String sql; 
	    	            PreparedStatement pst;
	    	            ResultSet rs;  
	    	            String url,userName,userPwd;  
	    	             // 连接数据库的语句
	    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
	    	            userName="sa";  
	    	            userPwd="123";  
	    	            con=DriverManager.getConnection(url,userName,userPwd);  
	    	            sql="select 学号,姓名,性别,班级,出生年月,家庭地址,院系,入学时间  from 学生个人档案信息  where 学号='"+num+"'"; 
	    	            pst = con.prepareStatement(sql);    	            
	    	            rs=pst.executeQuery(); 
	    	            while(rs.next()) {
	    	            	xh=rs.getString("学号");
	    	            	xm=rs.getString("姓名");
	    	            	xb=rs.getString("性别");
	    	            	bj=rs.getString("班级");
	    	            	csny=rs.getString("出生年月");
	    	            	jtdz=rs.getString("家庭地址");
	    	            	yx=rs.getString("院系");
	    	            	rxsj=rs.getString("入学时间");   	
	    	            }
	    	            
	    	            String[][] data11= {
	    						{"学号",xh},{"姓名",xm},{"性别",xb},{"班级",bj},{"出生年月",csny},{"家庭地址",jtdz},{"院系",yx},{"入学时间",rxsj}
	    				};
	    	            
	    	            JTable tb=new JTable(data11,columnName);
		    			
		    			
		    			tb.setRowHeight(55);
		    			tb.getColumnModel().getColumn(0).setPreferredWidth(250);
		    			tb.getColumnModel().getColumn(1).setPreferredWidth(250);

		    			panel5.add(tb);
		    			cardLayout.show(panel, "5");
	    	            
	    	        }
	    	          catch(SQLException exp){  
	    	            System.out.println(exp);  
	    	        } 
	    	            	      		
	        	}	        					
           });			
	                
		}
	}
	
	
	//修改学生信息   失败
	class Item4ActionListener implements ActionListener{
		public void actionPerformed(ActionEvent e) {
			p4.add(userNum);
			p4.add(numField);
			
			panel4B.add(p4,BorderLayout.CENTER);
	        panel4C.add(btn4);
	     
	        panel4.add(panel4B);
	        panel4.add(panel4C);
	        panel4.setLayout(new GridLayout(2,1,0,100));	  
     
	        cardLayout.show(panel,"4");     
	        
	        btn4.addActionListener(new ActionListener() {
	        	public void actionPerformed(ActionEvent e) {
	        		JTable tb;
	        		String num;
	        	    String xh = null,xm = null,xb= null,bj= null,csny= null,yx= null,rxsj= null,jtdz= null;
	        		num=numField.getText(); 
	    	        try{  
	    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); //加载数据库驱动 
	    	           
	    	        }  
	    	        catch(ClassNotFoundException ex){  
	    	        System.out.println(ex);  
	    	        }     	        
	    	        try{  
	    	            Connection con;  
	    	            String sql; 
	    	            PreparedStatement pst;
	    	            ResultSet rs;  
	    	            String url,userName,userPwd;  
	    	             // 连接数据库的语句
	    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
	    	            userName="sa";  
	    	            userPwd="123";  
	    	            con=DriverManager.getConnection(url,userName,userPwd);  
	    	            sql="select 学号,姓名,性别,班级,出生年月,家庭地址,院系,入学时间  from 学生个人档案信息  where 学号='"+num+"'"; 
	    	            pst = con.prepareStatement(sql);    	            
	    	            rs=pst.executeQuery(); 
	    	            while(rs.next()) {
	    	            	xh=rs.getString("学号");
	    	            	xm=rs.getString("姓名");
	    	            	xb=rs.getString("性别");
	    	            	bj=rs.getString("班级");
	    	            	csny=rs.getString("出生年月");
	    	            	jtdz=rs.getString("家庭地址");
	    	            	yx=rs.getString("院系");
	    	            	rxsj=rs.getString("入学时间");   	
	    	            }
	    	            
	    	            String[] columnName= {"属性","信息"};
		    			String[][] data= {
		    					{"学号",xh},{"姓名",xm},{"性别",xb},{"班级",bj},{"出生年月",csny},{"家庭地址",jtdz},{"院系",yx},{"入学时间",rxsj}
		    			};
		    			
		    			tb=new JTable(data,columnName);
		    			tb.setRowHeight(40);
		    			tb.getColumnModel().getColumn(0).setPreferredWidth(250);
		    			tb.getColumnModel().getColumn(1).setPreferredWidth(250);

		    			panel6.add(tb);
		    			panel6.add(btn5);
		    			    			
		    			cardLayout.show(panel, "6");
		    			
		    			
		    			
		    			//确认修改按钮监视器
		    			btn5.addActionListener(new ActionListener() {
		    	        	public void actionPerformed(ActionEvent e) {
		    	        		
		    	        		String data1[]=new String[8];
		    	        		for(int i=0;i<8;i++) {
		    	        			data1[i]=tb.getValueAt(i,1).toString();        			
		    	        		}
		    	     
		    	    	        try{  
		    	    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); //加载数据库驱动 
		    	    	           
		    	    	        }  
		    	    	        catch(ClassNotFoundException ex){  
		    	    	        System.out.println(ex);  
		    	    	        }  
		    	    	        try{  
		    	    	            Connection con;  
		    	    	            Statement sql;  
		    	    	           
		    	    	            int k;
		    	    	            
		    	    	            String url,userName,userPwd;  
		    	    	             // 连接数据库的语句
		    	    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
		    	    	            userName="sa";  
		    	    	            userPwd="123";  
		    	    	            con=DriverManager.getConnection(url,userName,userPwd);  
		    	    	            sql=con.createStatement();  
		    	    	            
	    	    	            	k=sql.executeUpdate("update 学生个人档案信息 set 姓名='"+data1[1]+"' ,性别='"+data1[2]+"' ,班级='"+data1[3]+"' ,出生年月='"+data1[4]+"' ,家庭地址='"+data1[5]+"' ,院系='"+data1[6]+"' ,入学时间='"+data1[7]+"' where 学号='"+data1[0]+"'"); 
	    	    	            	if(k>0) {
	    	    	            		JOptionPane.showMessageDialog(null, "信息修改成功！","消息对话框",JOptionPane.WARNING_MESSAGE); 
	    	    	            	}
	    	    	            	else {
	    	    	            		JOptionPane.showMessageDialog(null, "信息修改失败！","消息对话框",JOptionPane.WARNING_MESSAGE); 
	    	    	            	}
	    	    	            	 
	    	    	                dispose();  
		    	    	            }
		    	    	             
		    	    	        catch(SQLException exp){  
		    	    	            System.out.println(exp);  
		    	    	        } 
   	            	      		
		    	        	}	        					
	
		    	         });
		    				    			
	    	            
	    	        }
	    	          catch(SQLException exp){  
	    	            System.out.println(exp);  
	    	        } 
	    	            	      		
	        	}	        					
           });			
			
			
		}
	}

}

Teach_UI.java

package studentmanage;

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Vector;

import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.table.DefaultTableModel;
import studentmanage.UpPsw.BtnActionListener;

public class Teach_UI extends JFrame{
	
	CardLayout cardLayout=new CardLayout();
	BorderLayout borderLayout=new BorderLayout();
	
	JComboBox<String> c1 = new JComboBox<String>();//创建下拉列表
	JComboBox<String> c2 = new JComboBox<String>();//创建下拉列表
	
	JComboBox<String> c3 = new JComboBox<String>();//创建下拉列表
	JComboBox<String> c4 = new JComboBox<String>();//创建下拉列表
	
	JComboBox<String> c5 = new JComboBox<String>();//创建下拉列表
	JComboBox<String> c6 = new JComboBox<String>();//创建下拉列表
	
	
	
	JLabel l1 = new JLabel("班级:");
	JLabel l2 = new JLabel("学期:");

	JMenuBar menubar=new JMenuBar();
	JMenu menu=new JMenu("教师权限");
	JMenuItem item1=new JMenuItem("录入学生成绩");
	JMenuItem item2=new JMenuItem("删除学生成绩");
	JMenuItem item3=new JMenuItem("查找学生成绩");
	JMenuItem item4=new JMenuItem("修改学生成绩");
	
	JPanel panel1=new JPanel();
	JPanel panel1B=new JPanel();
	JPanel panel1C=new JPanel();
	JPanel panel2=new JPanel();
	JPanel panel2B=new JPanel();
	JPanel panel2C=new JPanel();
	JPanel panel3=new JPanel();
	JPanel panel3B=new JPanel();
	JPanel panel3C=new JPanel();
	JPanel panel4=new JPanel();
	JPanel panel4B=new JPanel();
	JPanel panel4C=new JPanel();
	JPanel panel=new JPanel();
	JPanel panel5=new JPanel();
	JPanel panel6=new JPanel();
	JPanel p=new JPanel();
	JPanel p0=new JPanel();
	JPanel p1=new JPanel();
	JPanel p2=new JPanel();
	JPanel p3=new JPanel();
	JPanel p4=new JPanel();
	
	JButton btn0=new JButton("确认班级和学期");
	//JButton btn00=new JButton("确认");
	JButton btn1=new JButton("提交成绩");
	JButton btn2=new JButton("删除成绩");
	JButton btn3=new JButton("查询成绩");
	JButton btn4=new JButton("修改成绩");
	JButton btn5=new JButton("确认修改");
	
	JScrollPane ScrollPane = new JScrollPane();
	

	
	String c1s=null;
	String c2s=null;
	
	

	JLabel userNum=new JLabel("学生学号");
	JLabel userName=new JLabel("学生姓名");
	JTextField numField=new JTextField(15);
	JTextField nameField=new JTextField(15);
	

	
	JTable table2,jTable;
	//JTable table1=new JTable(data,columnName);
		

	public Teach_UI() {	
		
		Dimension screenSize=Toolkit.getDefaultToolkit().getScreenSize();
	    setBounds((screenSize.width-800)/2,(screenSize.height-600)/2,800,600);
		
		setTitle("学生信息管理系统——教师");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
		
		//下列列表中选项
		c1.addItem("软件1701");  
		c1.addItem("软件1702");
		
		c2.addItem("2019秋季学期");  
		c2.addItem("2020春季学期");
		
		c3.addItem("软件1701");  
		c3.addItem("软件1702");
		
		c4.addItem("2019秋季学期");  
		c4.addItem("2020春季学期");
		
		c5.addItem("软件1701");  
		c5.addItem("软件1702");
		
		c6.addItem("2019秋季学期");  
		c6.addItem("2020春季学期");
		

		menu.add(item1);
		menu.add(item3);
		menu.add(item4);
		
		menubar.add(menu);
		this.setJMenuBar(menubar);
		
		panel1.setLayout(borderLayout);    //panel1容器
		
		panel.setLayout(cardLayout);  //卡片布局
		
		panel.add(panel1,"1");   //panel1相当于panel的组件
		panel.add(panel2,"2");
		panel.add(panel3,"3");
		panel.add(panel4,"4");
		panel.add(panel5,"5");
		panel.add(panel6,"6");
		
		panel.setBackground(Color.decode("#A9A9A9"));
		panel1.setBackground(Color.decode("#A9A9A9"));
		panel1C.setBackground(Color.decode("#A9A9A9"));
		panel1B.setBackground(Color.decode("#A9A9A9"));
		panel2.setBackground(Color.decode("#A9A9A9"));
		panel2B.setBackground(Color.decode("#A9A9A9"));
		panel2C.setBackground(Color.decode("#A9A9A9"));
		panel3.setBackground(Color.decode("#A9A9A9"));
		panel3B.setBackground(Color.decode("#A9A9A9"));
		panel3C.setBackground(Color.decode("#A9A9A9"));
		panel4.setBackground(Color.decode("#A9A9A9"));
		panel4B.setBackground(Color.decode("#A9A9A9"));
		panel4C.setBackground(Color.decode("#A9A9A9"));
		panel5.setBackground(Color.decode("#A9A9A9"));
		panel6.setBackground(Color.decode("#A9A9A9"));
		p.setBackground(Color.decode("#A9A9A9"));
		p0.setBackground(Color.decode("#A9A9A9"));
		p1.setBackground(Color.decode("#A9A9A9"));
		p2.setBackground(Color.decode("#A9A9A9"));
		p3.setBackground(Color.decode("#A9A9A9"));
		p4.setBackground(Color.decode("#A9A9A9"));
		
		add(panel);
		
		
		item1.addActionListener(new Item1ActionListener());
		//item2.addActionListener(new Item2ActionListener());
		item3.addActionListener(new Item3ActionListener());
		item4.addActionListener(new Item4ActionListener());	
			
	}
	
	
	public Vector getNextRow(ResultSet rs, ResultSetMetaData rsmd)   throws SQLException {
        Vector currentRow = new Vector();                         // 定义一个向量,用于存放记录
        for (int i = 1; i <= rsmd.getColumnCount(); ++i)
            currentRow.addElement(rs.getString(i));               // 获取记录
        return currentRow;                                        // 返回记录
    }
	
	
	
	public void displayResultSet(ResultSet rs,JPanel p) throws SQLException {
        boolean moreRecords = rs.next();             // 定位到达第一条记录
        
        if (!moreRecords) {
            JOptionPane.showMessageDialog(null, "结果集中无记录", "无记录",
                    JOptionPane.INFORMATION_MESSAGE);
            dispose(); 
            return;
        }

        Vector rows = new Vector();
        Vector columnHeads = new Vector();
        try {
            ResultSetMetaData rsmd = rs.getMetaData();                // 获得rs结果集中列属性信息
            for (int i = 1; i <= rsmd.getColumnCount(); ++i)
                columnHeads.addElement(rsmd.getColumnName(i)); // 获得列名(将列名存放至向量columnHeads)

            do {
                rows.addElement(getNextRow(rs, rsmd));
            } 
            while (rs.next()); // 利用循环获得所有记录
            jTable = new JTable(rows, columnHeads); // 将获得的行列数据信息作为参数重新构造表格视图
            jTable.setRowHeight(55);
            jTable.getColumnModel().getColumn(0).setPreferredWidth(200);
            jTable.getColumnModel().getColumn(1).setPreferredWidth(200);
            jTable.getColumnModel().getColumn(2).setPreferredWidth(200);
            jTable.getColumnModel().getColumn(3).setPreferredWidth(200);
            JScrollPane scroller = new JScrollPane(jTable);// 创建带有滚动条的面板,并将表格视图加入
            p.add(scroller, BorderLayout.CENTER); // 将面板重新加入溶器中
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
	
	

	//录入学生成绩
	class Item1ActionListener implements ActionListener{
		public void actionPerformed(ActionEvent e) {
			
			//p4.removeAll();
				
	        panel1B.add(btn1);
	        
	        panel1C.add(l1);
	        panel1C.add(c1);
	        
	        panel1C.add(l2);
	        panel1C.add(c2);
	        
	        panel1C.add(btn0); 
	        
	        panel1.add(panel1C,borderLayout.NORTH);
	        panel1.add(p1,borderLayout.CENTER);
	        panel1.add(panel1B,borderLayout.SOUTH);
	        
	
	        cardLayout.first(panel);
	        
	        c1s=c1.getSelectedItem().toString();
	        c2s=c2.getSelectedItem().toString();
	        
	        
	        //确认按钮  --------------------------------------------------------------------------------------------------
	        btn0.addActionListener(new ActionListener() {
	        	public void actionPerformed(ActionEvent e) {
	        		p1.removeAll();
	        		
	        		if(c1s.equals("软件1701")&&c2s.equals("2019秋季学期")) {
	        			
		    	        try{  
		    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");   //加载数据库
		    	           
		    	        }  
		    	        catch(ClassNotFoundException ex){  
		    	        System.out.println(ex);  
		    	        }     	        
		    	        try{  
		    	            Connection con;                                                //连接数据库
		    	            String sql; 
		    	            PreparedStatement pst;
		    	            ResultSet rs;  
		    	            String url,userName,userPwd;  
		    	             // 连接数据库的语句
		    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
		    	            userName="sa";  
		    	            userPwd="123";  
		    	            con=DriverManager.getConnection(url,userName,userPwd);  
		    	            sql="select * from 软件1701班2019秋季学期成绩表 ";    //*全部
		    	            pst = con.prepareStatement(sql);    	            
		      	            rs=pst.executeQuery();    //调用语句   数据库的数据————>
		    	            displayResultSet(rs,p1);
		    	            
		    	        }
		    	          catch(SQLException exp){  
		    	            System.out.println(exp);  
		    	        } 
	    	        		
	    	        }else if(c1s.equals("软件1701")&&c2s.equals("2020春季学期")) {
	    	        	
	    	        	try{  
			    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
			    	           
			    	        }  
			    	        catch(ClassNotFoundException ex){  
			    	        System.out.println(ex);  
			    	        }     	        
			    	        try{  
			    	            Connection con;  
			    	            String sql; 
			    	            PreparedStatement pst;
			    	            ResultSet rs;  
			    	            String url,userName,userPwd;  
			    	             // 连接数据库的语句
			    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
			    	            userName="sa";  
			    	            userPwd="123";  
			    	            con=DriverManager.getConnection(url,userName,userPwd);  
			    	            sql="select * from 软件1701班2020春季学期成绩表 "; 
			    	            pst = con.prepareStatement(sql);    	            
			      	            rs=pst.executeQuery();  
			    	            displayResultSet(rs,p1);
			    	            
			    	        }
			    	          catch(SQLException exp){  
			    	            System.out.println(exp);  
			    	        } 
	    	        	
	    	        	
	    	        	
	    	        }else if(c1s.equals("软件1702")&&c2s.equals("2019秋季学期")) {
	    	        	
	    	        	try{  
			    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
			    	           
			    	        }  
			    	        catch(ClassNotFoundException ex){  
			    	        System.out.println(ex);  
			    	        }     	        
			    	        try{  
			    	            Connection con;  
			    	            String sql; 
			    	            PreparedStatement pst;
			    	            ResultSet rs;  
			    	            String url,userName,userPwd;  
			    	             // 连接数据库的语句
			    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
			    	            userName="sa";  
			    	            userPwd="123";  
			    	            con=DriverManager.getConnection(url,userName,userPwd);  
			    	            sql="select * from 软件1702班2019秋季学期成绩表 "; 
			    	            pst = con.prepareStatement(sql);    	            
			      	            rs=pst.executeQuery(); 
			    	            displayResultSet(rs,p1);
			    	            
			    	            
			    	        }
			    	          catch(SQLException exp){  
			    	            System.out.println(exp);  
			    	        } 
	    	        	
	    	        	
	    	        }else {
	    	        	
	    	        	try{  
			    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
			    	           
			    	        }  
			    	        catch(ClassNotFoundException ex){  
			    	        System.out.println(ex);  
			    	        }     	        
			    	        try{  
			    	            Connection con;  
			    	            String sql; 
			    	            PreparedStatement pst;
			    	            ResultSet rs;  
			    	            String url,userName,userPwd;  
			    	             // 连接数据库的语句
			    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
			    	            userName="sa";  
			    	            userPwd="123";  
			    	            con=DriverManager.getConnection(url,userName,userPwd);  
			    	            sql="select * from 软件1702班2020春季学期成绩表 "; 
			    	            pst = con.prepareStatement(sql);    	            
			      	            rs=pst.executeQuery();
			    	            displayResultSet(rs,p1);
			    	            
			    	        }
			    	          catch(SQLException exp){  
			    	            System.out.println(exp);  
			    	        } 
	
	    	        	
	    	        }
	
	        	}
	        });
	        
	        //p1.removeAll();
	        
	        	
	         //确认提交 按钮----------------------------------------------------------------------------------------------
	        btn1.addActionListener(new ActionListener() {                                  //给按钮添加监视器   按下按钮有反应
	        	public void actionPerformed(ActionEvent e) {
	        		String data[][]=new String[8][4];
	        		int n = 0;    	    	        
	    	        try{  
	    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");  
	    	           
	    	        }  
	    	        catch(ClassNotFoundException ex){  
	    	        System.out.println(ex);  
	    	        }  
	    	        try{  
	    	            Connection con;  
	    	            String sql; 
	    	            PreparedStatement pst;
	    	            ResultSet rs;  
	    	            String url,userName,userPwd;  
	    	             // 连接数据库的语句
	    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
	    	            userName="sa";  
	    	            userPwd="123";  
	    	            con=DriverManager.getConnection(url,userName,userPwd);     	            
	    	            
	    	            for(int i=0;i<jTable.getRowCount();i++) {
	    	            	for(int j=0;j<jTable.getColumnCount();j++) {	
	    	            		data[i][j]=jTable.getValueAt(i,j).toString();
	    	            	}		        			
		        		}
	    	            
	    	            if(c1s.equals("软件1701")&&c2s.equals("2019秋季学期")) {
	    	            	for(int i=0;i<jTable.getRowCount();i++) {
	    	            		//pst = con.createStatement();    	            
	    	            		//pst.executeQuery("update 软件1701班2019秋季学期成绩表  set 成绩='"+data[i][3]+"' where 学号='"+data[i][0]+"'");
	    	            	pst = con.prepareStatement("update 软件1701班2019秋季学期成绩表  set 成绩='"+data[i][3]+"' where 学号='"+data[i][0]+"'");
	    	            	pst.executeUpdate(); 
	    	            	
		        		}
	    	            }else if(c1s.equals("软件1701")&&c2s.equals("2020春季学期")) {
	    	            	for(int i=0;i<jTable.getRowCount();i++) {
	    	            		//pst = con.createStatement();    	            
	    	            		//pst.executeQuery("update 软件1701班2020春季学期成绩表  set 成绩='\"+data[i][3]+\"' where 学号='\"+data[i][0]+\"'");
	    	            		
		    	            	pst = con.prepareStatement("update 软件1701班2020春季学期成绩表  set 成绩='"+data[i][3]+"' where 学号='"+data[i][0]+"'");
		    	            	pst.executeUpdate(); 
	    	            	}
	    	            	
	    	            }else if(c1s.equals("软件1702")&&c2s.equals("2019秋季学期")) {
	    	            	for(int i=0;i<jTable.getRowCount();i++) {
	    	            		//pst = con.createStatement();    	            
	    	            		//pst.executeQuery("update 软件1702班2019秋季学期成绩表  set 成绩='"+data[i][3]+"' where 学号='"+data[i][0]+"'");
	    	            		
		    	            	pst = con.prepareStatement("update 软件1702班2019秋季学期成绩表  set 成绩='"+data[i][3]+"' where 学号='"+data[i][0]+"'");
		    	            	pst.executeUpdate(); 
	    	            	}
	    	            	
	    	            }else {
	    	            	for(int i=0;i<jTable.getRowCount();i++) {
	    	            		//pst = con.createStatement();    	            
	    	            		//pst.executeQuery("update 软件1702班2020春季学期成绩表  set 成绩='"+data[i][3]+"' where 学号='"+data[i][0]+"'");
		    	            	pst = con.prepareStatement("update 软件1702班2020春季学期成绩表  set 成绩='"+data[i][3]+"' where 学号='"+data[i][0]+"'");
		    	            	pst.executeUpdate(); 
	    	            	}
	    	            	
	    	            }
	    	            
	    	            
	    	            
                        con.close();
	    	            JOptionPane.showMessageDialog(null, "录入成绩成功！","消息对话框",JOptionPane.WARNING_MESSAGE);  
    	                //dispose(); 
	    	        }
	    	          catch(SQLException exp){  
	    	            System.out.println(exp);  
	    	        } 
	    	            	      		
	        	}	        					
           });
        }
	}
		
	
	//删除学生成绩   --------------------------------------------------------------------------------------------------------------
	/*
	class Item2ActionListener  implements ActionListener{
		public void actionPerformed(ActionEvent e) {
			
			
		}
	}
	*/
	

    //查找学生成绩--------------------------------------------------------------------------------------------------------------
	class Item3ActionListener implements ActionListener{
		public void actionPerformed(ActionEvent e) {
			
			//p4.removeAll();
			
			p0.add(l1);
	        p0.add(c3);
	        
	        p0.add(l2);
	        p0.add(c4);
	        p0.add(btn3);
	        
	        c1s=c3.getSelectedItem().toString();
	        c2s=c4.getSelectedItem().toString();
		

	        //panel3B.add(p0,BorderLayout.NORTH);

	        panel3.setLayout(new BorderLayout());
	        panel3.add(p0,BorderLayout.NORTH);
	        panel3.add(p2,BorderLayout.CENTER);
	        

	        cardLayout.show(panel,"3");     
	        
	        //确认查询按钮
	        btn3.addActionListener(new ActionListener() {
	        	public void actionPerformed(ActionEvent e) {
                    p2.removeAll();
	        		
	        		if(c1s.equals("软件1701")&&c2s.equals("2019秋季学期")) {
	        			
		    	        try{  
		    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
		    	           
		    	        }  
		    	        catch(ClassNotFoundException ex){  
		    	        System.out.println(ex);  
		    	        }     	        
		    	        try{  
		    	            Connection con;  
		    	            String sql; 
		    	            PreparedStatement pst;
		    	            ResultSet rs;  
		    	            String url,userName,userPwd;  
		    	             // 连接数据库的语句
		    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
		    	            userName="sa";  
		    	            userPwd="123";  
		    	            con=DriverManager.getConnection(url,userName,userPwd);  
		    	            sql="select * from 软件1701班2019秋季学期成绩表 "; 
		    	            pst = con.prepareStatement(sql);    	            
		    	            rs=pst.executeQuery(); 
		    	            displayResultSet(rs,p2);
		    	            
		    	        }
		    	          catch(SQLException exp){  
		    	            System.out.println(exp);  
		    	        } 
	    	        		
	    	        }else if(c1s.equals("软件1701")&&c2s.equals("2020春季学期")) {
	    	        	
	    	        	try{  
			    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
			    	           
			    	        }  
			    	        catch(ClassNotFoundException ex){  
			    	        System.out.println(ex);  
			    	        }     	        
			    	        try{  
			    	            Connection con;  
			    	            String sql; 
			    	            Statement pst;
			    	            ResultSet rs;  
			    	            String url,userName,userPwd;  
			    	             // 连接数据库的语句
			    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
			    	            userName="sa";  
			    	            userPwd="123";  
			    	            con=DriverManager.getConnection(url,userName,userPwd);  
			    	            sql="select * from 软件1701班2020春季学期成绩表 "; 
			    	            pst = con.createStatement();    	            
			    	            rs=pst.executeQuery(sql); 
			    	            displayResultSet(rs,p2);
			    	            
			    	        }
			    	          catch(SQLException exp){  
			    	            System.out.println(exp);  
			    	        } 
	    	        	
	    	        	
	    	        	
	    	        }else if(c1s.equals("软件1702")&&c2s.equals("2019秋季学期")) {
	    	        	
	    	        	try{  
			    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
			    	           
			    	        }  
			    	        catch(ClassNotFoundException ex){  
			    	        System.out.println(ex);  
			    	        }     	        
			    	        try{  
			    	            Connection con;  
			    	            String sql; 
			    	            PreparedStatement pst;
			    	            ResultSet rs;  
			    	            String url,userName,userPwd;  
			    	             // 连接数据库的语句
			    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
			    	            userName="sa";  
			    	            userPwd="123";  
			    	            con=DriverManager.getConnection(url,userName,userPwd);  
			    	            sql="select * from 软件1702班2019秋季学期成绩表 "; 
			    	            pst = con.prepareStatement(sql);    	            
			    	            rs=pst.executeQuery(); 
			    	            displayResultSet(rs,p2);
			    	            
			    	            
			    	        }
			    	          catch(SQLException exp){  
			    	            System.out.println(exp);  
			    	        } 
	    	        	
	    	        	
	    	        }else {
	    	        	
	    	        	try{  
			    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
			    	           
			    	        }  
			    	        catch(ClassNotFoundException ex){  
			    	        System.out.println(ex);  
			    	        }     	        
			    	        try{  
			    	            Connection con;  
			    	            String sql; 
			    	            PreparedStatement pst;
			    	            ResultSet rs;  
			    	            String url,userName,userPwd;  
			    	             // 连接数据库的语句
			    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
			    	            userName="sa";  
			    	            userPwd="123";  
			    	            con=DriverManager.getConnection(url,userName,userPwd);  
			    	            sql="select * from 软件1702班2020春季学期成绩表 "; 
			    	            pst = con.prepareStatement(sql);    	            
			    	            rs=pst.executeQuery(); 
			    	            displayResultSet(rs,p2);
			    	            
			    	        }
			    	          catch(SQLException exp){  
			    	            System.out.println(exp);  
			    	        } 
	
	    	        	
	    	        }
	        		
	    	            	      		
	        	}	        					
           });			
	                
		}
	}
	
	
	
	
	//修改学生成绩 ------------------------------------------------------------------------------------------------------------ 
	class Item4ActionListener implements ActionListener{
		public void actionPerformed(ActionEvent e) {
			
			//p4.removeAll();
			
			p.add(l1);
	        p.add(c5);
	        p.add(l2);
	        p.add(c6);
	        p.add(btn4);  //修改成绩按钮
			
			p3.add(btn5);
			        
	        panel4.setLayout(new BorderLayout());
	        panel4.add(p,BorderLayout.NORTH);
	        panel4.add(p4,BorderLayout.CENTER);
	        panel4.add(p3,BorderLayout.SOUTH);
	        
	        cardLayout.show(panel,"4");   
	        
	        c1s=c5.getSelectedItem().toString();
	        c2s=c6.getSelectedItem().toString();
	        
	        //修改成绩-----------------------------------------------------------------------------------------
	        btn4.addActionListener(new ActionListener() {
	        	public void actionPerformed(ActionEvent e) {
                     p4.removeAll();
	        		
	        		if(c1s.equals("软件1701")&&c2s.equals("2019秋季学期")) {
	        			
		    	        try{  
		    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
		    	           
		    	        }  
		    	        catch(ClassNotFoundException ex){  
		    	        System.out.println(ex);  
		    	        }     	        
		    	        try{  
		    	            Connection con;  
		    	            String sql; 
		    	            PreparedStatement pst;
		    	            ResultSet rs;  
		    	            String url,userName,userPwd;  
		    	             // 连接数据库的语句
		    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
		    	            userName="sa";  
		    	            userPwd="123";  
		    	            con=DriverManager.getConnection(url,userName,userPwd);  
		    	            sql="select * from 软件1701班2019秋季学期成绩表 "; 
		    	            pst = con.prepareStatement(sql);    	            
		    	            rs=pst.executeQuery(); 
		    	            displayResultSet(rs,p4);
		    	            
		    	        }
		    	          catch(SQLException exp){  
		    	            System.out.println(exp);  
		    	        } 
	    	        		
	    	        }else if(c1s.equals("软件1701")&&c2s.equals("2020春季学期")) {
	    	        	
	    	        	try{  
			    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
			    	           
			    	        }  
			    	        catch(ClassNotFoundException ex){  
			    	        System.out.println(ex);  
			    	        }     	        
			    	        try{  
			    	            Connection con;  
			    	            String sql; 
			    	            PreparedStatement pst;
			    	            ResultSet rs;  
			    	            String url,userName,userPwd;  
			    	             // 连接数据库的语句
			    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
			    	            userName="sa";  
			    	            userPwd="123";  
			    	            con=DriverManager.getConnection(url,userName,userPwd);  
			    	            sql="select * from 软件1701班2020春季学期成绩表 "; 
			    	            pst = con.prepareStatement(sql);    	            
			    	            rs=pst.executeQuery(); 
			    	            displayResultSet(rs,p4);
			    	            
			    	        }
			    	          catch(SQLException exp){  
			    	            System.out.println(exp);  
			    	        } 
	    	        	
	    	        	
	    	        	
	    	        }else if(c1s.equals("软件1702")&&c2s.equals("2019秋季学期")) {
	    	        	
	    	        	try{  
			    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
			    	           
			    	        }  
			    	        catch(ClassNotFoundException ex){  
			    	        System.out.println(ex);  
			    	        }     	        
			    	        try{  
			    	            Connection con;  
			    	            String sql; 
			    	            PreparedStatement pst;
			    	            ResultSet rs;  
			    	            String url,userName,userPwd;  
			    	             // 连接数据库的语句
			    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
			    	            userName="sa";  
			    	            userPwd="123";  
			    	            con=DriverManager.getConnection(url,userName,userPwd);  
			    	            sql="select * from 软件1702班2019秋季学期成绩表 "; 
			    	            pst = con.prepareStatement(sql);    	            
			    	            rs=pst.executeQuery(); 
			    	            displayResultSet(rs,p4);
			    	            
			    	            
			    	        }
			    	          catch(SQLException exp){  
			    	            System.out.println(exp);  
			    	        } 
	    	        	
	    	        	
	    	        }else {
	    	        	
	    	        	try{  
			    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
			    	           
			    	        }  
			    	        catch(ClassNotFoundException ex){  
			    	        System.out.println(ex);  
			    	        }     	        
			    	        try{  
			    	            Connection con;  
			    	            String sql; 
			    	            PreparedStatement pst;
			    	            ResultSet rs;  
			    	            String url,userName,userPwd;  
			    	             // 连接数据库的语句
			    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
			    	            userName="sa";  
			    	            userPwd="123";  
			    	            con=DriverManager.getConnection(url,userName,userPwd);  
			    	            sql="select * from 软件1702班2020春季学期成绩表 "; 
			    	            pst = con.prepareStatement(sql);    	            
			    	            rs=pst.executeQuery(); 
			    	            displayResultSet(rs,p4);
			    	            
			    	        }
			    	          catch(SQLException exp){  
			    	            System.out.println(exp);  
			    	        } 
	
	    	        	
	    	        }
	
	        	}
	        		
	        		
	        	});	
	        
	        
	        
	        //确认修改成绩----------------------------------------------------------------------------------------
	        btn5.addActionListener(new ActionListener() {
	        	public void actionPerformed(ActionEvent e) {
	        		//p4.removeAll();
	        		String data[][]=new String[100][4];
	        		int n = 0;    	    	        
	    	        try{  
	    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");  
	    	           
	    	        }  
	    	        catch(ClassNotFoundException ex){  
	    	        System.out.println(ex);  
	    	        }  
	    	        try{  
	    	            Connection con;  
	    	            String sql; 
	    	            PreparedStatement pst;
	    	            ResultSet rs;  
	    	            String url,userName,userPwd;  
	    	             // 连接数据库的语句
	    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
	    	            userName="sa";  
	    	            userPwd="123";  
	    	            con=DriverManager.getConnection(url,userName,userPwd);     	            
	    	            
	    	            for(int i=0;i<jTable.getRowCount();i++) {
	    	            	for(int j=0;j<jTable.getColumnCount();j++) {	
	    	            		data[i][j]=jTable.getValueAt(i,j).toString();
	    	            	}		        			
		        		}
	    	            
	    	            if(c1s.equals("软件1701")&&c2s.equals("2019秋季学期")) {
	    	            	for(int i=0;i<jTable.getRowCount();i++) {
	    	            	pst = con.prepareStatement("update 软件1701班2019秋季学期成绩表  set 成绩='"+data[i][3]+"' where 学号='"+data[i][0]+"'");
	    	            	pst.executeUpdate(); 
	    	            	
		        		}
	    	            }else if(c1s.equals("软件1701")&&c2s.equals("2020春季学期")) {
	    	            	for(int i=0;i<jTable.getRowCount();i++) {
		    	            	pst = con.prepareStatement("update 软件1701班2020春季学期成绩表  set 成绩='"+data[i][3]+"' where 学号='"+data[i][0]+"'");
		    	            	pst.executeUpdate(); 
	    	            	}
	    	            	
	    	            }else if(c1s.equals("软件1702")&&c2s.equals("2019秋季学期")) {
	    	            	for(int i=0;i<jTable.getRowCount();i++) {
		    	            	pst = con.prepareStatement("update 软件1702班2019秋季学期成绩表  set 成绩='"+data[i][3]+"' where 学号='"+data[i][0]+"'");
		    	            	pst.executeUpdate(); 
	    	            	}
	    	            	
	    	            }else {
	    	            	for(int i=0;i<jTable.getRowCount();i++) {
		    	            	pst = con.prepareStatement("update 软件1702班2020春季学期成绩表  set 成绩='"+data[i][3]+"' where 学号='"+data[i][0]+"'");
		    	            	pst.executeUpdate(); 
	    	            	}
	    	            	
	    	            }
	    	            

                        con.close();
	    	            JOptionPane.showMessageDialog(null, "修改成绩成功！","消息对话框",JOptionPane.WARNING_MESSAGE);  
    	                dispose(); 
	    	        }
	    	          catch(SQLException exp){  
	    	            System.out.println(exp);  
	    	        } 
	    	            	      		
	        	}
	        		

	        	       					
           });
			
			
	        }
	}

}

Stud_UI.java

package studentmanage;
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Vector;

import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.table.DefaultTableModel;

import studentmanage.UpPsw.BtnActionListener;

public class Stud_UI extends JFrame{

	CardLayout cardLayout=new CardLayout();
	JMenuBar menubar=new JMenuBar();
	JMenu menu=new JMenu("学生权限");
	JMenuItem item1=new JMenuItem("查询个人信息");
	JMenuItem item2=new JMenuItem("查询成绩信息");
	JPanel panel1=new JPanel();
	JPanel panel1B=new JPanel();
	JPanel panel1C=new JPanel();
	JPanel panel2=new JPanel();
	JPanel panel2B=new JPanel();
	JPanel panel2C=new JPanel();
	JPanel panel3=new JPanel();
	JPanel panel4=new JPanel();
	JPanel panel=new JPanel();
	JPanel p=new JPanel();
	JPanel p1=new JPanel();
	JButton btn1=new JButton("查询信息");
	JButton btn10=new JButton("退出");
	JButton btn2=new JButton("查询成绩");
	JButton btn20=new JButton("退出");
	
	JComboBox<String> c1 = new JComboBox<String>();//创建下拉列表
	JComboBox<String> c2 = new JComboBox<String>();//创建下拉列表
	
	JLabel label1=new JLabel("学期");
	JLabel label2=new JLabel("班级");
	
	JTextField numField=new JTextField(15);
	
	String num=null;
	String c1s,c2s;
	
	JTable table1,table2,jTable;
		

	public Stud_UI(JTextField numField) {
		
	    num=numField.getText();
		
		c1.addItem("2019秋季学期");  
		c1.addItem("2020春季学期");
		
		c2.addItem("软件1701");  
		c2.addItem("软件1702");
		
		num=numField.getText().toString();
		
		Dimension screenSize=Toolkit.getDefaultToolkit().getScreenSize();
	    setBounds((screenSize.width-800)/2,(screenSize.height-600)/2,800,600);
		
		setTitle("学生信息管理系统——学生");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
		
		menu.add(item1);
		menu.add(item2);
		
		menubar.add(menu);
		this.setJMenuBar(menubar);
		
		panel.setLayout(cardLayout);
		
		panel.add(panel1,"1");
		panel.add(panel2,"2");
		panel.add(panel3,"3");
		panel.add(panel4,"4");
		
		panel.setBackground(Color.decode("#A9A9A9"));
		panel1.setBackground(Color.decode("#A9A9A9"));
		panel2.setBackground(Color.decode("#A9A9A9"));
		panel2B.setBackground(Color.decode("#A9A9A9"));
		panel2C.setBackground(Color.decode("#A9A9A9"));
		panel3.setBackground(Color.decode("#A9A9A9"));
		panel4.setBackground(Color.decode("#A9A9A9"));
		p.setBackground(Color.decode("#A9A9A9"));
		p1.setBackground(Color.decode("#A9A9A9"));


		add(panel);		
		item1.addActionListener(new Item1ActionListener());
		item2.addActionListener(new Item2ActionListener());	
			
	}
	
	
	public Vector getNextRow(ResultSet rs, ResultSetMetaData rsmd)   throws SQLException {
        Vector currentRow = new Vector();                         // 定义一个向量,用于存放记录
        for (int i = 1; i <= rsmd.getColumnCount(); ++i)
            currentRow.addElement(rs.getString(i));               // 获取记录
        return currentRow;                                        // 返回记录
    }
	
	
	
	public void displayResultSet(ResultSet rs,JPanel p) throws SQLException {
        boolean moreRecords = rs.next();             // 定位到达第一条记录
        
        if (!moreRecords) {
            JOptionPane.showMessageDialog(null, "结果集中无记录", "无记录",
                    JOptionPane.INFORMATION_MESSAGE);
            dispose(); 
            return;
        }

        Vector rows = new Vector();
        Vector columnHeads = new Vector();
        try {
            ResultSetMetaData rsmd = rs.getMetaData();                // 获得rs结果集中列属性信息
            for (int i = 1; i <= rsmd.getColumnCount(); ++i)
                columnHeads.addElement(rsmd.getColumnName(i)); // 获得列名(将列名存放至向量columnHeads)

            do {
                rows.addElement(getNextRow(rs, rsmd));
            } 
            while (rs.next()); // 利用循环获得所有记录
            jTable = new JTable(rows, columnHeads); // 将获得的行列数据信息作为参数重新构造表格视图
            jTable.setRowHeight(55);
            jTable.getColumnModel().getColumn(0).setPreferredWidth(200);
            jTable.getColumnModel().getColumn(1).setPreferredWidth(200);
            jTable.getColumnModel().getColumn(2).setPreferredWidth(200);
            jTable.getColumnModel().getColumn(3).setPreferredWidth(200);
            
            JScrollPane scroller = new JScrollPane(jTable);// 创建带有滚动条的面板,并将表格视图加入
            p.add(scroller, BorderLayout.CENTER); // 将面板重新加入溶器中
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
	
	
	
	
	//查询个人信息--------------------------------------------------------------------------------------------
	class Item1ActionListener implements ActionListener{
		public void actionPerformed(ActionEvent e) {
			
			p1.removeAll();
			
			panel1.add(p1);
				
			try{  
  	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
  	           
  	        }  
  	        catch(ClassNotFoundException ex){  
  	        System.out.println(ex);  
  	        }     	        
  	        try{  
  	            Connection con;  
  	            String sql; 
  	            PreparedStatement pst;
  	            ResultSet rs;  
  	            String url,userName,userPwd;  
  	             // 连接数据库的语句
  	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
  	            userName="sa";  
  	            userPwd="123";  
  	            con=DriverManager.getConnection(url,userName,userPwd);  
  	            sql="select * from 学生个人档案信息  where 学号='"+num+"' "; 
  	            pst = con.prepareStatement(sql);    	            
  	            rs=pst.executeQuery(); 
  	            displayResultSet(rs,p1);
  	            
  	        }
  	          catch(SQLException exp){  
  	            System.out.println(exp);  
  	        } 
	        
  	      cardLayout.show(panel,"1"); 			
	                
		}
	}
		
	//查询成绩信息-------------------------------------------------------------------------------------------------------
	class Item2ActionListener implements ActionListener{
		public void actionPerformed(ActionEvent e) {

			panel2B.add(label1);
			panel2B.add(c1);
			panel2B.add(label2);
			panel2B.add(c2);
			panel2B.add(btn2);
			panel2C.add(p);
			panel2.setLayout(new BorderLayout());
			panel2.add(panel2B,BorderLayout.NORTH);
	        panel2.add(panel2C,BorderLayout.CENTER);
     
	        cardLayout.show(panel,"2"); 
	        
	        c1s=c1.getSelectedItem().toString();
	        c2s=c2.getSelectedItem().toString();
	         
	        
	        btn2.addActionListener(new ActionListener() {
	        	public void actionPerformed(ActionEvent e) {
                    p.removeAll();
	        		
	        		if(c2s.equals("软件1701")&&c1s.equals("2019秋季学期")) {
	        			
		    	        try{  
		    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
		    	           
		    	        }  
		    	        catch(ClassNotFoundException ex){  
		    	        System.out.println(ex);  
		    	        }     	        
		    	        try{  
		    	            Connection con;  
		    	            String sql; 
		    	            PreparedStatement pst;
		    	            ResultSet rs;  
		    	            String url,userName,userPwd;  
		    	             // 连接数据库的语句
		    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
		    	            userName="sa";  
		    	            userPwd="123";  
		    	            con=DriverManager.getConnection(url,userName,userPwd);  
		    	            sql="select * from 软件1701班2019秋季学期成绩表 where 学号='"+num+"'"; 
		    	            pst = con.prepareStatement(sql);    	            
		    	            rs=pst.executeQuery(); 
		    	            displayResultSet(rs,p);
		    	            
		    	        }
		    	          catch(SQLException exp){  
		    	            System.out.println(exp);  
		    	        } 
	    	        		
	    	        }else if(c2s.equals("软件1701")&&c1s.equals("2020春季学期")) {
	    	        	
	    	        	try{  
			    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
			    	           
			    	        }  
			    	        catch(ClassNotFoundException ex){  
			    	        System.out.println(ex);  
			    	        }     	        
			    	        try{  
			    	            Connection con;  
			    	            String sql; 
			    	            PreparedStatement pst;
			    	            ResultSet rs;  
			    	            String url,userName,userPwd;  
			    	             // 连接数据库的语句
			    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
			    	            userName="sa";  
			    	            userPwd="123";  
			    	            con=DriverManager.getConnection(url,userName,userPwd);  
			    	            sql="select *from 软件1701班2020春季学期成绩表 where 学号='"+num+"'"; 
			    	            pst = con.prepareStatement(sql);    	            
			    	            rs=pst.executeQuery(); 
			    	            displayResultSet(rs,p);
			    	            
			    	        }
			    	          catch(SQLException exp){  
			    	            System.out.println(exp);  
			    	        } 
	    	        	
	    	        	
	    	        	
	    	        }else if(c2s.equals("软件1702")&&c1s.equals("2019秋季学期")) {
	    	        	
	    	        	try{  
			    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
			    	           
			    	        }  
			    	        catch(ClassNotFoundException ex){  
			    	        System.out.println(ex);  
			    	        }     	        
			    	        try{  
			    	            Connection con;  
			    	            String sql; 
			    	            PreparedStatement pst;
			    	            ResultSet rs;  
			    	            String url,userName,userPwd;  
			    	             // 连接数据库的语句
			    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
			    	            userName="sa";  
			    	            userPwd="123";  
			    	            con=DriverManager.getConnection(url,userName,userPwd);  
			    	            sql="select * from 软件1702班2019秋季学期成绩表 where 学号='"+num+"'"; 
			    	            pst = con.prepareStatement(sql);    	            
			    	            rs=pst.executeQuery(); 
			    	            displayResultSet(rs,p);
			    	            
			    	            
			    	        }
			    	          catch(SQLException exp){  
			    	            System.out.println(exp);  
			    	        } 
	    	        	
	    	        	
	    	        }else {
	    	        	
	    	        	try{  
			    	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
			    	           
			    	        }  
			    	        catch(ClassNotFoundException ex){  
			    	        System.out.println(ex);  
			    	        }     	        
			    	        try{  
			    	            Connection con;  
			    	            String sql; 
			    	            PreparedStatement pst;
			    	            ResultSet rs;  
			    	            String url,userName,userPwd;  
			    	             // 连接数据库的语句
			    	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
			    	            userName="sa";  
			    	            userPwd="123";  
			    	            con=DriverManager.getConnection(url,userName,userPwd);  
			    	            sql="select * from 软件1702班2020春季学期成绩表 where 学号='"+num+"'"; 
			    	            pst = con.prepareStatement(sql);    	            
			    	            rs=pst.executeQuery(); 
			    	            displayResultSet(rs,p);
			    	            
			    	        }
			    	          catch(SQLException exp){  
			    	            System.out.println(exp);  
			    	        } 
	
	    	        	
	    	        }
	 		
	        		
	        	}	        					
           });			
	                
		}
	}
}

UpPsw.java

package studentmanage;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.swing.*;
import studentmanage.DenLu.Button1ActionListener;
public class UpPsw extends JFrame{
	
	JLabel label;
	JLabel usernum;
	JLabel newPwd1,newPwd2;
	JTextField numField;
	JPasswordField newpwdField1;
	JPasswordField newpwdField2;
	JButton btn;
	JPanel pane1,pane2,pane3,pane0,pane4;
	
	
	public UpPsw() {
		
		Dimension screenSize=Toolkit.getDefaultToolkit().getScreenSize();
	    setBounds((screenSize.width-800)/2,(screenSize.height-600)/2,800,600);
	    
	    label=new JLabel("★请输入账号和新密码，并确认新密码。若两次输入的密码不一致，您将无法修改密码！",JLabel.LEFT);
	    label.setFont(new Font("宋体", Font.PLAIN, 20));
	    
	    usernum=new JLabel("输入账号",JLabel.CENTER);
	    usernum.setFont(new Font("宋体", Font.PLAIN, 20));
	    
	    newPwd1=new JLabel("输入新密码",JLabel.CENTER);
	    newPwd1.setFont(new Font("宋体", Font.PLAIN, 20));
	    
	    newPwd2=new JLabel("确认新密码",JLabel.CENTER);
	    newPwd2.setFont(new Font("宋体", Font.PLAIN, 20));
	    
	    
	    
	    numField=new JTextField(21);
	    newpwdField1=new JPasswordField(20);
	    newpwdField2=new JPasswordField(20);
		btn=new JButton("确定修改");
		btn.setFont(new Font("宋体", Font.PLAIN, 20));
		btn.setBackground(Color.WHITE);
		
		pane0=new JPanel();
		pane1=new JPanel();
		pane2=new JPanel();
		pane3=new JPanel();
		pane4=new JPanel();
		
		pane0.setBackground(Color.decode("#A9A9A9"));
		pane1.setBackground(Color.decode("#A9A9A9"));
		pane2.setBackground(Color.decode("#A9A9A9"));
		pane3.setBackground(Color.decode("#A9A9A9"));
		pane4.setBackground(Color.decode("#A9A9A9"));
		
		
		btn.addActionListener(new BtnActionListener());
		
		pane4.add(label);
		
		pane0.add(usernum);
		pane0.add(numField);
		
		pane1.add(newPwd1);
		pane1.add(newpwdField1);
		
		pane2.add(newPwd2);
		pane2.add(newpwdField2);
		
		pane3.add(btn);
		
		add(pane4);
		add(pane0);
		add(pane1);
		add(pane2);
		add(pane3);
		
        this.setLayout(new GridLayout(5,1,0,0));
		
		setTitle("修改密码界面");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);
		
		
	}
	
	class BtnActionListener implements ActionListener{
		public void actionPerformed(ActionEvent e) {
	        String num,psw1,psw2; 
	        num=numField.getText(); 
	        psw1=newpwdField1.getText();  
	        psw2=newpwdField2.getText(); 
 
	        try{  
	          Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); //加载数据库驱动 
	           
	        }  
	        catch(ClassNotFoundException ex){  
	        System.out.println(ex);  
	        }  
	        try{  
	            Connection con;  
	            Statement sql;  
	            int k;
	            
	            String url,userName,userPwd;  
	            url="jdbc:sqlserver://localhost:1433;DatabaseName=StudentInfo";
	            userName="sa";  
	            userPwd="123";  
	            con=DriverManager.getConnection(url,userName,userPwd);  
	            sql=con.createStatement();  
	            if(psw1.equals(psw2)) {
	            	k=sql.executeUpdate("update 用户信息表 set 密码= '"+psw2+"'  where 账号='"+num+"'"); 
	            	if(k>0) {
	            		JOptionPane.showMessageDialog(null, "密码修改成功！","消息对话框",JOptionPane.WARNING_MESSAGE); 
	            	}
	            	 
	                dispose();  
	            }
	            else {
	            	JOptionPane.showMessageDialog(null, "两次输入密码不一致！!","消息对话框",JOptionPane.WARNING_MESSAGE);
	            }
	        }
	            
	        catch(SQLException exp){  
	            System.out.println(exp);  
	        } 
			  		
	    		
	}
    	
	

	}
}

二、运行结果

三、代码优化

代码优化