package com.news.dao;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;
/**
* 封装连接数据库，进行数据库操作工具类
* @author mxl
* @version 1.0
*
*/
public class BaseDao {
private static String url ="";
private static String driver ="";
private static String uname ="";
private static String upwd ="";
private static Connection con= null;
private static PreparedStatement st =null;
private static ResultSet rs = null;
static{
try {
//读取配置文件
Properties pro = new Properties();
InputStream is = BaseDao.class.getClassLoader().getResourceAsStream("db.properties");
pro.load(is);
url = pro.getProperty("url");
driver = pro.getProperty("driver");
uname = pro.getProperty("uname");
upwd = pro.getProperty("upwd");
Class.forName(driver);
} catch (ClassNotFoundException e) {
e.printStackTrace();
System.out.println("驱动类错误");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* 获取连接对象
* @return Connection
*/
public static Connection getConnection(){
try {
con = DriverManager.getConnection(url,uname ,upwd );
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return con;
}
/**
* 用于增删改的通用方法
* @param sql SQL语句
* @param params 参数集
* @return 影响行数
*/
public static int update(String sql,Object[] params){
int result = 0;
try {
st =getConnection().prepareStatement(sql);//insert into b values(?,?,?)
if(params!=null && params.length>0){
for(int i=0;i<params.length;i++){
st.setObject(i+1, params[i]);
}
}
result = st.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}finally{
BaseDao.close();
}
return result;
}
/**
* 用于查询的方法
* @param sql
* @param params
* @return 结果
*/
public static ResultSet query(String sql,Object[] params){
try {
st =getConnection().prepareStatement(sql);
if(params!=null && params.length>0){
for(int i=0;i<params.length;i++){
st.setObject(i+1, params[i]);
}
}
rs = st.executeQuery();
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}
/**
* 释放资源的方法
*/
public static void close(){
try {
if(rs!=null){
rs.close();
}
if(st!=null){
st.close();
}
if(con!=null){
con.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}