JdbcConnect.java
package com.company;
import org.junit.jupiter.api.Test;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.sql.*;
import java.util.Properties;
public class JdbcConnect {
@Test
public void connection() throws IOException {
//通过Properties对象获取配置文件信息
Properties properties=new Properties();
properties.load(new FileInputStream("src\mysql.properties"));
Connection connection;
try {
Class.forName(properties.getProperty("driver"));//反射方法注册驱动
// String url="jdbc:mysql://localhost:3306/mydb";在配置文件中
// serverTimezone=UTC 有时参数需要加上这一句"
connection = DriverManager.getConnection
(properties.getProperty("url"),properties.getProperty("user"),properties.getProperty("password"));
System.out.println(connection);//测试连接
//创建sql语句 update insert delete老师说返回影响的行数（可我这返回boolean类型） 用statement.execute
// String sql="insert into user(`id`,`name`,`pwd`,`sex`,`phone`,`address`) values(4,'小菜鸡','123','男','1374545','北京')";
String sql1="select *from user";
//创建执行这对象statement
Statement statement=connection.createStatement();
//执行sql语句
// System.out.println(statement.execute(sql));
//执行sql1语句,返回resultset对象 用statement.executeQuery
ResultSet rs=statement.executeQuery(sql1);
//使用while循环取出数据
while(rs.next()){//光标下移，有数据就进入循环体
int id = rs.getInt("id");
String name=rs.getString("name");
String pwd = rs.getString("pwd");
System.out.println("id"+id+"name"+name+"pwd"+pwd);//测试
}
//关闭连接,后连的先关
rs.close();
statement.close();
connection.close();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
mysql.properties
user=root password=root url=jdbc:mysql://localhost:3306/mydb?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8 driver=com.mysql.jdbc.Driver
