imaildaoimpl.java

运用JSP/servlet/JavaBean 技术

package com.lovo.dao;

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

import com.lovo.myutil.DBManager;
import com.lovo.po.Mail;
import com.lovo.po.MailVo;

public class IMailDaoImpl implements IMailDao
{

	/* （非 Javadoc）
	 * @see com.lovo.dao.IMailDao#sendMail(com.lovo.po.Mail)
	 */
	public boolean sendMail(Mail mail)
	{
		/** 存数据库连接对象 */
		Connection conn = null;
		/** 存预编译语句 */
		PreparedStatement state = null;
		/** 存查询返回结果集 */
		ResultSet rs = null;
		String sql = "insert into t_mail(mailStatus, mailTitle, mailContent," +
				" userId, whoSended, whoReceive) values(?, ?, ?, ?, ?, ?)";//添加邮件语句
		/** 获取数据库连接对象 */
		conn = DBManager.getConnection();
		int result = -1;//存储添加邮件后的返回信息
		try
		{
			/** 创建sql的预编译语句 */
			state = conn.prepareStatement(sql);
			/** 为sql设置邮件状态参数 */
			state.setInt(1, mail.getMailStatus());
			/** 为sql设置邮件标题参数 */
			state.setString(2, mail.getMailTitle());
			/** 为sql设置邮件内容参数 */
			state.setString(3, mail.getMailContent());
			/** 为sql设置邮件所属参数 */
			state.setInt(4, mail.getUserId());
			/** 为sql设置发件人参数 */
			state.setInt(5, mail.getWhoSended());
			/** 为sql设置收件人参数 */
			state.setInt(6, mail.getWhoReceive());
			/** 执行添加 */
			result = state.executeUpdate();
		}
		catch (SQLException e)
		{
			e.printStackTrace();
		}
		finally
		{
			/** 关闭所有的数据库连接对象 */
			DBManager.closeAll(conn, state, rs);
		}
		return result == 1 ? true : false;
	}

	/* （非 Javadoc）
	 * @see com.lovo.dao.IMailDao#queryMail(int, int)
	 */
	public List<MailVo> queryMail(int userId, int mailStatus)
	{
		/** 存数据库连接对象 */
		Connection conn = null;
		/** 存预编译语句 */
		PreparedStatement state = null;
		/** 存查询返回结果集 */
		ResultSet rs = null;
		List<MailVo> list = null;//存查询结果
		String sql = "select mailId, mailTitle, mailContent, whoSended, " +
				"u1.emailName as whoSendedName, whoReceive, " +
				"u2.emailName as whoReceiveName " +
				"from t_mail, t_user u1, t_user u2 " +
				"where t_mail.whoSended = u1.userId " +
				"and t_mail.whoReceive = u2.userId " +
				"and mailStatus = ? " +
				"and t_mail.userId = ?";//查询邮件语句
		/** 获取数据库连接对象 */
		conn = DBManager.getConnection();
		try
		{
			/** 创建sql的预编译语句 */
			state = conn.prepareStatement(sql);
			/** 为sql设置邮件状态参数 */
			state.setInt(1, mailStatus);
			/** 为sql设置邮件所属参数 */
			state.setInt(2, userId);
			/** 执行查询 */
			rs = state.executeQuery();
			MailVo mailVo = null;//用于封装对象以便存入list
			boolean flag = true;//如果有结果集，那么用它来作为创ArrayList的开关
			/**
			 * 有结果集的话，循环封装成Mail对象并添加到list里
			 */
			while(rs.next())
			{
				/**
				 * 有结果集，那么在第一次的时候创建一个ArrayList对象
				 */
				if(flag)
				{
					/** 创建一个ArrayList对象用于存放Mail对象 */
					list = new ArrayList<MailVo>();
					/** 关闭开关，不再创建新的ArrayList，以免覆盖之前的 */
					flag = false;
				}
				/** 创建一个Mail对象，用来封装当前邮件信息 */
				mailVo = new MailVo();
				/** 封装MailId */
				mailVo.setMailId(rs.getInt("mailId"));
				/** 封装MailStatus */
				mailVo.setMailStatus(mailStatus);
				/** 封装MailTitle */
				mailVo.setMailTitle(rs.getString("mailTitle"));
				/** 封装MailContent */
				mailVo.setMailContent(rs.getString("mailContent"));
				/** 封装UserId */
				mailVo.setUserId(userId);
				/** 封装WhoSended */
				mailVo.setWhoSended(rs.getInt("whoSended"));
				/** 封装WhoReceive */
				mailVo.setWhoReceive(rs.getInt("whoReceive"));
				/** 封装WhoSendedName */
				mailVo.setWhoSendedName(rs.getString("whoSendedName"));
				/** 封装WhoReceiveName */
				mailVo.setWhoReceiveName(rs.getString("whoReceiveName"));
				/** 将封装好所有信息的Mail对象添加到list */
				list.add(mailVo);
			}
		}
		catch (SQLException e)
		{
			e.printStackTrace();
		}
		finally
		{
			/** 关闭所有的数据库连接对象 */
			DBManager.closeAll(conn, state, rs);
		}
		return list;
	}

	/* （非 Javadoc）
	 * @see com.lovo.dao.IMailDao#deleteMail(int[])
	 */
	public int deleteMail(int[] mailIds)
	{
		/** 存数据库连接对象 */
		Connection conn = null;
		/** 存预编译语句 */
		PreparedStatement state = null;
		/** 存查询返回结果集 */
		ResultSet rs = null;
		int result = 0;//存储删除邮件后的返回信息
		String sql = "delete from t_mail where mailId = ?";//删除邮件语句
		/** 获取数据库连接对象 */
		conn = DBManager.getConnection();
		try
		{
			/** 创建sql的预编译语句 */
			state = conn.prepareStatement(sql);
			for(int i = 0; i < mailIds.length; i++)
			{
				/** 为sql设置要删除的邮件的mailId */
				state.setInt(1, mailIds[i]);
				/** 执行删除 */
				result += state.executeUpdate();
			}
		}
		catch (SQLException e)
		{
			e.printStackTrace();
		}
		finally
		{
			/** 关闭所有的数据库连接对象 */
			DBManager.closeAll(conn, state, rs);
		}
		return result;
	}

	/* （非 Javadoc）
	 * @see com.lovo.dao.IMailDao#updateMail(com.lovo.po.Mail)
	 */
	public boolean updateMail(Mail mail)
	{
		/** 存数据库连接对象 */
		Connection conn = null;
		/** 存预编译语句 */
		PreparedStatement state = null;
		/** 存查询返回结果集 */
		ResultSet rs = null;
		int result = -1;//存储更新邮件后的返回信息
		String sql = "update t_mail set mailStatus = ?, mailTitle = ?, " +
				"mailContent = ?, userId = ?, whoSended = ?, whoReceive = ? " +
				"where mailId = ?";//更新邮件语句
		/** 获取数据库连接对象 */
		conn = DBManager.getConnection();
		try
		{
			/** 创建sql的预编译语句 */
			state = conn.prepareStatement(sql);
			/** 设置参数 */
			state.setInt(1, mail.getMailStatus());
			state.setString(2, mail.getMailTitle());
			state.setString(3, mail.getMailContent());
			state.setInt(4, mail.getUserId());
			state.setInt(5, mail.getWhoSended());
			state.setInt(6, mail.getWhoReceive());
			state.setInt(7, mail.getMailId());
			/** 执行更新 */
			result = state.executeUpdate();
		}
		catch (SQLException e)
		{
			e.printStackTrace();
		}
		finally
		{
			/** 关闭所有的数据库连接对象 */
			DBManager.closeAll(conn, state, rs);
		}
		return result == 1 ? true : false;
	}

	public int moveToDeleted(int[] mailIds)
	{
		/** 存数据库连接对象 */
		Connection conn = null;
		/** 存预编译语句 */
		PreparedStatement state = null;
		/** 存查询返回结果集 */
		ResultSet rs = null;
		int result = 0;//存储更新邮件后的返回信息
		String sql = "update t_mail set mailStatus = 4 where mailId = ?";//更新邮件状态语句
		/** 获取数据库连接对象 */
		conn = DBManager.getConnection();
		try
		{
			/** 创建sql的预编译语句 */
			state = conn.prepareStatement(sql);
			for(int i = 0; i < mailIds.length; i++)
			{
				/** 为sql设置要更新的邮件的mailId */
				state.setInt(1, mailIds[i]);
				/** 执行删除 */
				result += state.executeUpdate();
			}
		}
		catch (SQLException e)
		{
			e.printStackTrace();
		}
		finally
		{
			/** 关闭所有的数据库连接对象 */
			DBManager.closeAll(conn, state, rs);
		}
		return result;
	}

}