Java使用JDBC连接MySQL报错

JDBC连MySQL出错

• 问题描述
• • 查看MySQL版本
  • 引入mysql-connector-java.jar
  • 写Java代码
  • 报错
  • 修改代码
  • 运行成功

问题描述

以下所有内容均是windows下操作

今天本着复习JDBC这块知识，想着对面试也有帮助，创建了maven项目，引入了mysql-connector-java.jar,结果创建完成后报错。

The server time zone value '�й���׼ʱ��' is unrecognized or represents more than one time zone. 
You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.
           

查看MySQL版本

(前提是设置了mysql到环境变量path)

mysql -V
           

其它查看mysql版本的方式

引入mysql-connector-java.jar

pom.xml:

<!-- 跟自己mysql版本选着对应的驱动版本 -->
<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<version>8.0.16</version>
</dependency>
           

写Java代码

package ssm.jdbc;


import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.sql.*;

public class JDBCTest {
    private static final Logger log = LoggerFactory.getLogger(JDBCTest.class);
    public static void main(String[] args) {
        try {
            String url = "jdbc:mysql://localhost:3306/spider";
            String username = "root";
            String passwd = "123456";
            // 注册驱动
            Class.forName("com.mysql.jdbc.Driver");
            Connection connection = null;
            Statement statement = null;
            // 获取连接对象
            try {
                connection = DriverManager.getConnection(url,username,passwd);
                statement = connection.createStatement();
                // 创建sql执行对象
                String sql = "select id,name from user";
                //执行sql语句
                ResultSet resultSet = statement.executeQuery(sql);
                while(resultSet.next()){
                    int id = resultSet.getInt("id");
                    String name = resultSet.getString("name");
                    User u = new User(id,name);
                    log.info(u.toString());
                }
            } catch (SQLException e) {
                e.printStackTrace();
            } finally{
                // 关闭资源
                try {
                    statement.close();
                    connection.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}

           

报错

Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
java.sql.SQLException: The server time zone value '�й���׼ʱ��' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.
	...
Caused by: com.mysql.cj.exceptions.InvalidConnectionAttributeException: The server time zone value '�й���׼ʱ��' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.
	...
Exception in thread "main" java.lang.NullPointerException
	at ssm.jdbc.JDBCTest.main(JDBCTest.java:39)

Process finished with exit code 1
           

修改代码

将JDBC的url属性修改：

运行成功

运行是成功了，但是有警告：将old driver

com.mysql.jdbc.Driver

替换成new driver

com.mysql.cj.jdbc.Driver

作为一个强迫症，果断根据提示替换驱动名，然后再运行，发现提示消失。

//          Class.forName("com.mysql.jdbc.Driver");
            Class.forName("com.mysql.cj.jdbc.Driver");