managerdaoimpl.java

本程序主要实现对管理系统的初步管理

package org.ads123.goodsmanagers.dao.impl;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.JavaChina.myjdbc.ConnectPool;
import org.ads123.goodsmanagers.dao.ManagerDao;
import org.ads123.goodsmanagers.dto.Manager;

public class ManagerDaoImpl implements ManagerDao{

	public Manager findManagerByUsername(String username) {
		Manager manager = null;
		
		Connection conn = ConnectPool.getInstance().getConnection();
		PreparedStatement pstm = null;
		ResultSet rst = null;
		String sql = "select password from manager where username = ?";
		try {
			pstm = conn.prepareStatement(sql);
			pstm.setString(1, username);
			rst = pstm.executeQuery();
			if(rst.next()){
				String password = rst.getString("password");
				manager = new Manager();
				manager.setUsername(username);
				manager.setPassword(password);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			try {
				if(rst != null){
					rst.close();
				}
				if(pstm != null){
					pstm.close();
				}
				if(conn != null && !conn.isClosed()){
					ConnectPool.getInstance().destroyConnection(conn);
				}
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		return manager;
	}
	
	public static void main(String[] args) {
		ManagerDaoImpl managerDaoImpl = new ManagerDaoImpl();
		Manager manager = managerDaoImpl.findManagerByUsername("adsd123");
		if(manager != null){
			System.out.println(manager.getUsername() + "   " + manager.getPassword());
		}else{
			System.out.println("此用户不存在！");
		}
	}

}