无法创建与数据库服务器MySQL 8.0的连接

Question

This error has already been dealt with several times in the forum, but I meet the error for the first time after updating to MySQL 8.0 and the solutions proposed for previous versions didn't work. I found, however, two ways to prevent the error:

• Run MySQL from a console window and exit.
• Launch the Workbench and click on "Local instance MySQL57" (That name hasn't changed after the update.) Close the workbench again.

Having done so, the error will not happen any more until I restart the PC. Launching "Computer Management" (Win10) and looking at the services, I see "MySQL80" with a status of "Running" right after PC startup. So that seems to be ok.

I am using MySQL Server version: 8.0.12 and mysql-connector-java 8.0.12.

Here's the java code I use to get a connection. With 8.0 I had to add time zone information to make it work. See what other flags I tested as well.

import java.sql.*;
import java.util.*;

public class Test {
  String url= "jdbc:mysql://localhost/myDb?autoReconnect=true&useSSL=false";

  public Test() {
    try {
      Connection conn= DriverManager.getConnection(url+"&serverTimezone=CET",
//  "&useJDBCCompliantTimezoneShift=true"+
//  "&useUnicode=true&characterEncoding=UTF-8"+
//  "&zeroDateTimeBehavior=CONVERT_TO_NULL",
    "root",
    "mypass");
      System.out.println(conn);
    }
    catch(SQLException e) {
      System.out.println(e);
    }
    System.exit(0);
  }


  public static void main(String args[]) {
    EventQueue.invokeLater(Test::new);
  }

}

Edit: Just updated to server and J/Connector 8.0.13, but the java.sql.SQLNonTransientConnectionException persists.

Answer 1

In my given test case one has to remove "&useSSL=false".

In Connector/J 8.0 "useSSL" has been replaced by "sslMode" and "useSSL" has, indeed, been deprecated. But to me "deprecated" doesn't mean "illegal". So now we know: Beware of deprecation!

At least at my location (central Europe) specifying serverTimezone seems to be a must (Runtime error).