companydao.java

一个jsp的oa系统,里面有很多亮点学习!

package com.oa.lp.dao;

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

import com.oa.lp.model.Company;
import com.oa.lp.model.Employee;
import com.oa.lp.model.LinkMan;
import com.oa.lp.util.DTOPopulator;

public class CompanyDAO {
	private Connection conn;

	public Connection getConn() {
		return conn;
	}

	public void setConn(Connection conn) {
		this.conn = conn;
	}
	/**
	 * 通过公司ID查找到公司信息
	 * @param companyId
	 * @return
	 * @throws Exception
	 */
	public Company getCompany(int companyId) throws Exception{
		Company company = new Company();
		List list=null;
		String sql = "select * from COMPANY where COMPANY_ID=?";
		PreparedStatement pstmt = conn.prepareStatement(sql);
		pstmt.setInt(1,companyId);
		ResultSet rs = pstmt.executeQuery();
		list = DTOPopulator.populate(rs, Company.class);
		if(list.size()>0){
			company = (Company)list.get(0);
		}
		rs.close();
		pstmt.close();
		return company;
	}
	/**
	 * 列出公司信息
	 */
	public List listCompany() throws Exception{
		List list = null; 
		String sql = "select * from COMPANY";
		PreparedStatement pstmt = conn.prepareStatement(sql);
		ResultSet rs = pstmt.executeQuery();
		//将结果集中的每一行记录封装成一个对象,再放进集合返回
		list = DTOPopulator.populate(rs, Company.class);
		pstmt.close();
		return list;
	}
	/**
	 * 更新公司信息
	 * @param company
	 * @throws SQLException
	 */
	public void updateCompany(Company company) throws SQLException{
		String sql = "update COMPANY set COMPANY_NAME=?,COMPANY_HOMEPAGE=?,COMPANY_COPYRIGHT=?";
		PreparedStatement pstmt = conn.prepareStatement(sql);
		
		pstmt.setString(1,company.getCompanyName());
		pstmt.setString(2,company.getCompanyHomePage());
		pstmt.setString(3,company.getCompanyCopyRight());
		
		pstmt.executeUpdate();
		pstmt.close();
	}
}