changepassword.java

用JAVA做的图书借阅信息系统

import java.awt.*;
import java.sql.*;
import java.awt.event.*;
public class ChangePassWord extends Dialog implements ActionListener
{
	Button 确认,取消;
	Label l1,l2,l3,l4;
	TextField t1,t2,t3,t4;
	Panel p;
	Label message;
	Connection con;
    Statement sql;
    ResultSet rs;
	ChangePassWord(Frame f,String s,boolean b)
	{
		super(f,s,b);
		p=new Panel();
		GridLayout net=new GridLayout(5,2);
		net.setHgap(5);
		net.setVgap(10);
		p.setLayout(net);
		确认=new Button("确认");
		取消=new Button("取消");
		l1=new Label("请输入旧用户名：",Label.RIGHT);
		l2=new Label("请输入旧密码：",Label.RIGHT);
		l3=new Label("请输入新用户名：",Label.RIGHT);
		l4=new Label("请输入新密码：",Label.RIGHT);
		t1=new TextField(10);
		t2=new TextField(10);
		t3=new TextField(10);
		t4=new TextField(10);
		t2.setEchoChar('*');
		t4.setEchoChar('*');
		p.add(l1);p.add(t1);
		p.add(l2);p.add(t2);
		p.add(l3);p.add(t3);
		p.add(l4);p.add(t4);;
		p.add(确认);p.add(取消);
		message=new Label("",Label.CENTER);
		add(message,"South");
		add(new Label(),"North");
		add(new Label("             "),"East");
		add(new Label("             "),"West");
		add(p,"Center");
		确认.addActionListener(this);
		取消.addActionListener(this);
		setBounds(210,120,400,250);
		setVisible(true);
		validate();
	    addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e)
		    {
			  setVisible(false);
			  dispose();
		}});
	}
	public void actionPerformed(ActionEvent e)
	{
		if(e.getSource()==确认)
		{
			String name=t1.getText().trim();
			String pass=t2.getText().trim();
			String newname=t3.getText().trim();
			String newpass=t4.getText().trim();
			try
			{
				Class.forName("com.ms.jdbc.odbc.JdbcOdbcDriver");
			}
			catch(ClassNotFoundException e1)
			{
				message.setText("无法建立数据源！");
			}
			try
			{
				con=DriverManager.getConnection("jdbc:odbc:book","","");
				sql=con.createStatement();
			}
			catch(SQLException e2)
			{
				message.setText("没有找到数据表！");
			}
			try
			{
				rs=sql.executeQuery("SELECT 用户名,密码 FROM 用户信息表");
				boolean b=false;
				while ((b=rs.next())==true)
				{
					String tname=rs.getString("用户名");
					String tpass=rs.getString("密码");
					if(tname.equals(name)&&tpass.equals(pass)&&newname.length()!=0&&newpass.length()!=0)
					{
						b=true;
						String s1="'"+newname+"'";
						String s2="'"+newpass+"'";
						String s3="'"+tname+"'";
						String temp="UPDATE 用户信息表 SET 用户名="+s1+",密码="+s2+" WHERE 用户名="+s3;
						sql.executeUpdate(temp);
						message.setBackground(Color.red);
						message.setText("密码修改完毕！");
						try
						{
							Thread.sleep(3000);
						}
						catch(InterruptedException ee){}
						con.close();
						setVisible(false);
						dispose();
					}
				}
				if(b==false)
				{
					message.setBackground(Color.red);
					message.setText("旧密码或用户名有误，不能更改！");
						try
						{
							Thread.sleep(3000);
						}
						catch(InterruptedException ee){}
						con.close();
						setVisible(false);
						dispose();
				}		
			}
			catch(SQLException e3){}			
		}
		if(e.getSource()==取消)
		{
			setVisible(false);
			dispose();
		}
	}
}