當我們使用之前的方法通過jdbc連線mysql8.0版本時，會出現如下問題提示：

Wed Aug 29 15:38:16 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
java.sql.SQLException: The server time zone value '???ú±ê×??±??' 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.
	at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:127)
	at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:95)
	at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:87)
	at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:61)
	at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:71)
	at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:76)
	at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:862)
	at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:444)
	at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:230)
	at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:226)
	at java.sql.DriverManager.getConnection(Unknown Source)
	at java.sql.DriverManager.getConnection(Unknown Source)
	at com.brz.jdbc.demo1.JDBCUtils.main(JDBCUtils.java:29)
Caused by: com.mysql.cj.exceptions.InvalidConnectionAttributeException: The server time zone value '???ú±ê×??±??' 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.
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
	at java.lang.reflect.Constructor.newInstance(Unknown Source)
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:59)
	at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:83)
	at com.mysql.cj.util.TimeUtil.getCanonicalTimezone(TimeUtil.java:128)
	at com.mysql.cj.protocol.a.NativeProtocol.configureTimezone(NativeProtocol.java:2201)
	at com.mysql.cj.protocol.a.NativeProtocol.initServerSession(NativeProtocol.java:2225)
	at com.mysql.cj.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:1391)
	at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:993)
	at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:852)
	... 6 more
Exception in thread "main" java.lang.NullPointerException
	at com.brz.jdbc.demo1.JDBCUtils.main(JDBCUtils.java:39)
 

此時，我們只需要修改兩處即可解決問題：

1.在URL中加上時區資訊：serverTimezone=GMT即可解決問題，如果需要使用gmt+8時區，需要寫成GMT%2B8

顯示SSL連線，即：useSSL=false 。

private static final String URL = "jdbc:mysql://localhost:3306/mydb?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8&useSSL=false";

2.修改新版本的驅動包類名：

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

例項：

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * 使用JDBC訪問資料庫
 * @author brz
 *
 */
public class JDBCUtils {
	private static final String USER = "root";
	private static final String PASSWD = "123456";
	private static final String URL = "jdbc:mysql://localhost:3306/mydb?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8&useSSL=false";
	
	public static void main(String[] args) {
		//  1、註冊資料庫的驅動,使用反射註冊驅動
        try {
			Class.forName("com.mysql.cj.jdbc.Driver");
			System.out.println("註冊驅動成功");
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
        Connection connection = null;
         //2、獲得資料庫的連線訪問許可權
        try {
			connection = DriverManager.getConnection(URL, USER, PASSWD);
			System.out.println("連線資料庫成功");
        } catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
         //3、向資料庫傳送執行的SQL執行語句
        Statement statement = null;
        
        try {
			statement = connection.createStatement();
			//編寫SQL語句
			String sql = "delete from student where sid = 1";
			int row_count =statement.executeUpdate(sql);
			if (row_count>0) {
				System.out.println("刪除資料庫成功");
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			try {
				connection.rollback();
			} catch (Exception e1) {
				e1.printStackTrace();
			}
			
			
		}
        
         //4、獲取執行的返回結果
        
         //5、關閉資料庫連線
		 try {
			statement.close();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		
	}

}