logindao.java

老牌java开发的物流管理系统 详细的我也没有怎么看 好像是恒基的

package com.wl.dao;
import java.sql.ResultSet;
import java.sql.SQLException;

import com.wl.dbconnection.DBManager;
import com.wl.entity.Login;
public class LoginDAO {

	public LoginDAO() {
		
	}
	DBManager db = new DBManager();
	boolean flag;
	ResultSet rs = null;
	public boolean checkLogin(String name,String password) {
		flag = db.openDB();
		if(flag)
		{
		  try {
			db.ps = db.conn.prepareStatement("select * from logintable where LoginName=? and LoginPassword=?");
			db.ps.setString(1, name);
			db.ps.setString(2, password);
			rs = db.ps.executeQuery();
			if(rs.next()) {
				return true;
			}
			else{
				return false;
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		finally{
			db.closeDB();
		}
		}
		else {
			System.out.println("db fail");
		}
		return flag;
	}
	/**
	 * 根据名字查询管理员
	 * @param loginName
	 * @return
	 */
	public Login selectLoginByName(String loginName){
	    flag=db.openDB();
	    Login login=null;
	    if(flag){
	       try{
	       db.ps=db.conn.prepareStatement("select * from loginTable where LoginName=?");
	       db.ps.setString(1,loginName);
	       rs=db.ps.executeQuery();
	       while(rs.next()){
	    	   login=new Login(rs.getInt(1),rs.getString(2),rs.getString(3),rs.getString(4),rs.getString(5),rs.getInt(6));
	       }
	    	}
	    catch(Exception e){
	       System.out.print("出错了！");
	    }
	    finally{
	    	db.closeDB();
	    }
	    }
	    else{
	    	System.out.print("数据库打开失败！");
	    }
	    return login;
	}
	/**
	 * tian xiaoshun
	 * @param loginid
	 * @return
	 */
	public Login selectLoginById(int id){
	    flag=db.openDB();
	    Login login=null;
	    if(flag){
	       try{
	       db.ps=db.conn.prepareStatement("select * from loginTable where id=?");
	       db.ps.setInt(1,id);
	       rs=db.ps.executeQuery();
	       while(rs.next()){
	    	   login=new Login(rs.getInt(1),rs.getString(2),rs.getString(3),rs.getString(4),rs.getString(5),rs.getInt(6));
	       }
	    	}
	    catch(Exception e){
	       System.out.print("出错了！");
	    }
	    finally{
	    	db.closeDB();
	    }
	    }
	    else{
	    	System.out.print("数据库打开失败！");
	    }
	    return login;
	}
}