JDBC 驱动程序错误，无法连接到 mysql 服务器

Question

I keep getting the error messages when I run my code attempting to connect to an sql server

Exception in thread "main" java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
    at java.base/java.lang.Class.forName0(Native Method)
    at java.base/java.lang.Class.forName(Class.java:375)

This is my code. I've made sure to add connector/J to the classpath and still no chamge

import java.sql.*;

public class App {
    
    public static void main(String[] args) throws Exception {
        Class.forName("com.mysql.jdbc.Driver");
        Connection conn = DriverManager.getConnection(
                "jdbc:mysql://localhost:3306/vehicle", "root", "root"); // For MySQL only

        vehicle focus = new vehicle("Ford", "Focus", 200, 2004, 3000);

        System.out.println(focus.getMake());
    }
}

Answer 1

First of all, loading the JDBC driver using Class.forName is not necessary since JDBC 4.0 which was made available in 2006 (the driver registers its implementation as service provider and will be loaded by the ServiceLoader ).

Just remove this line and it should work. If you need the class name, its a good idea to consult the documentation of Connector/J. Take care to read the docs for the correct driver version because the class name changed (currently it's com.mysql.cj.jdbc.Driver).