最近有人问加哥怎么连接数据库,和数据库建立连接。下面给大家分享一下JDBC连接数据库的模版方法。加哥是以mysql为例,若是其他数据库替换层其他的即可。
步骤:
1.引入数据库架包
2.加载驱动
3.创建连接
4.进行相应数据库操作
5.关闭数据库连接。
下面直接给大家上代码:
package org.util;
import java.sql.*;
public class BaseDao {
//驱动
private static String driver = "com.mysql.jdbc.Driver";
private static String url = "jdbc:mysql://127.0.0.1:3306/mytest?characterEncoding=utf-8&serverTimezone=Asia/Shanghai";
//用户名
private static String username = "root";
//密码
private static String pwd = "123456";
/**
* 创建连接
* @return
*/
public static Connection getConnection(){
Connection connection=null;
//加载驱动
try {
Class.forName(driver);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
//建立连接获取Connection对象
try {
connection= DriverManager.getConnection(url,username,pwd);
} catch (SQLException e) {
e.printStackTrace();
}
return connection;
}
/**
* 关闭链接
* @param connection
* @param statement
* @param resultSet
*/
public static void closeAll(Connection connection, Statement statement, ResultSet resultSet){
try {
if(resultSet!=null){
resultSet.close();
}
if(statement!=null){
statement.close();
}
if (connection!=null){
connection.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
/**
* 执行增、删、改的方法
* @param sql
* @return
*/
public static int execute(String sql){
//获取链接
Connection connection=getConnection();
int flag=0;
try {
//创建Statement对象
Statement statement=connection.createStatement();
//执行sql语句
flag=statement.executeUpdate(sql);
//关闭链接
closeAll(connection,statement,null);
} catch (SQLException e) {
e.printStackTrace();
}
return flag;
}
/*
测试
*/
public static void main(String[] args) {
String sql = "SELECT * FROM bs_structure WHERE id = 1688350472671";
Connection connection = getConnection();
Statement statement = null;
try {
statement= connection.createStatement();
ResultSet resultSet = statement.executeQuery(sql);
while(resultSet.next()){
String typename = resultSet.getString(3);
System.out.println("类别名称:"+typename);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}