userdao.java

超市管理系统,jsp+javabean+sqlserver

package dao;

import java.sql.*;

import po.*;

public class UserDAO {
	Connection conn=null;
	Statement state=null;
	ResultSet rs=null;
	//判断是否是有效用户
	public boolean isUser(String username,String password)
	{
		boolean user=false;
		try {
			conn=Tools.getConnection();
			state=conn.createStatement();
			rs=state.executeQuery("select * from users where username= '"+username+"'and password= '"+password+"'");
			//如果找到了
			if(rs.next())
			{
				user=true;
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return user;
	}
    //通过用户名和密码查看用户级别
	public int grade(String username , String password)
	{
		int i = 0;
		try {
			conn=Tools.getConnection();
			state=conn.createStatement();
			rs = state.executeQuery("select Flag from users where Username = '"+username+"'and Password = '"+password+"'");
			if(rs.next())
			{
				i = rs.getInt("Flag");
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return i;
	}
 
        //返回用户的PO对象
		public UserPO qxyzpo(String username , String password)
		{ 
			UserPO uspo =null;
			
			  		 try {
			  			conn=Tools.getConnection();
						state=conn.createStatement();
				rs = state.executeQuery("select * from users where Username = '"+username+"'and Password = '"+password+"'");
				if(rs.next())
				{
					uspo = new UserPO();
					uspo.setUsername(rs.getString("Username"));
					uspo.setPassword(rs.getString("Password"));
					uspo.setFlag(rs.getInt("Flag"));
				}
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			return uspo;
		}
}