dbstu.java

用JSP制作的一个简单的登录界面

package org.baobao.dao;
import java.sql.*;
import java.util.*;
import org.baobao.javaBean.*;
public class dbStu
{
	private PreparedStatement ps = null;
	private ResultSet rs = null;
	
	public boolean queryUser(String stuName,int stuAge)
	{
		String sql = "select * from stuInfo where stuName=? and stuAge=?";
		try
		{
			ps = dbDao.getCon().prepareStatement(sql);
			ps.setString(1,stuName);
			ps.setInt(2,stuAge);
			rs = ps.executeQuery();
			if (rs.next())
			{
				return true;
			}else
			{
				return false;
			}
		}catch(Exception e)
		{
			e.printStackTrace();
			return false;
		}finally
		{
			try
			{
				rs.close();
				ps.close();
				dbDao.close();
			}catch(Exception e)
			{
				e.printStackTrace();
			}
		}
	}
	
	public List queryAll(String stuName)
	{
		String sql = "select * from stuInfo where stuName=? ";
		try
		{
			ps = dbDao.getCon().prepareStatement(sql);
			ps.setString(1,stuName);
			rs = ps.executeQuery();
			List<StuInfo> li = new ArrayList<StuInfo>();
			while(rs.next())
			{
				StuInfo si = new StuInfo();
				si.setStuId(rs.getInt(1));
				si.setStuName(rs.getString(2));
				si.setStuAge(rs.getInt(3));
				li.add(si);
			}
			return li;
		}catch(Exception e)
		{
			e.printStackTrace();
			return null;
		}finally
		{
			try
			{
				rs.close();
				ps.close();
				dbDao.close();
			}catch(Exception e)
			{
				e.printStackTrace();
			}
		}
	}
	
	public static void main(String [] args)
	{
		if (new dbStu().queryUser("莫邪",12))
		{
			System.out.println("用户名and密码正确。。");
		}else
		{
			System.out.println("错误的用户名or密码");
		}
	}
}