user_areadaoimpl.java

一个bbs论坛系统

package com.lovo.dao;

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

import com.lovo.util.DBUtil;

public class User_AreaDAOImpl implements User_AreaDAO {

	/**数据库连接对象*/
	private Connection con;

	/**预编译语句对象*/
	private PreparedStatement pre;

	/**结果集对象*/
	private ResultSet rs;
	
	public void insert(int userId, int areaId) throws SQLException {
		String sql = "insert into user_area(user_id, area_id) values(?, ?)";
		con = DBUtil.getDBUtil().getConnection();
		try {
			pre = con.prepareStatement(sql);
			pre.setInt(1, userId);
			pre.setInt(2, areaId);
			pre.executeUpdate();
		} catch (SQLException e) {
			e.printStackTrace();
			throw e;
		} finally {
			DBUtil.getDBUtil().close(rs);
			DBUtil.getDBUtil().close(pre);
			DBUtil.getDBUtil().close(con);
		}
	}
	
	public void delete(int userId, int areaId) throws SQLException {
		String sql = "delete from user_area where user_id = ? and area_id = ?";
		con = DBUtil.getDBUtil().getConnection();
		try {
			pre = con.prepareStatement(sql);
			pre.setInt(1, userId);
			pre.setInt(2, areaId);
			pre.executeUpdate();
		} catch (SQLException e) {
			e.printStackTrace();
			throw e;
		} finally {
			DBUtil.getDBUtil().close(rs);
			DBUtil.getDBUtil().close(pre);
			DBUtil.getDBUtil().close(con);
		}
	}
	
	public int queryAreaIdBy(int userId) throws SQLException {
		String sql = "select block_id from user_block where user_id = ?";
		con = DBUtil.getDBUtil().getConnection();
		int areaId = 0;
		try {
			pre = con.prepareStatement(sql);
			pre.setInt(1, userId);
			rs = pre.executeQuery();
			while(rs.next()) {
				areaId = rs.getInt("block_id");
			}
		} catch (SQLException e) {
			e.printStackTrace();
			throw e;
		} finally {
			DBUtil.getDBUtil().close(rs);
			DBUtil.getDBUtil().close(pre);
			DBUtil.getDBUtil().close(con);
		}
		return areaId;
	}

}