very basic getConnection("jdbc:mysql//localhost/3306/films/") cannot connect (mysql provided connector)

Question

When I compiled the code below and manuallu, I got "Impossible to load the driver jdbc-odbc" and with maven (mvn clean install -U) it goes one step further but cannot connect to the given database: localhost/3306/films), although I could test the DB with mysql Workbench application. Anyway if maven succeeds in loading the driver (first step) I would like to understand why. (When I said "manually" I mean that I have typed javac -cp path com.company.driver.TestJDBCmysql.java with .m2/repository as 'path' and I did not found where the driver furnished by mysql install on windows was located so I just indicated the jar downloaded by a first mvn install attempt)

package com.company.driver;
import java.sql.*;

public class TestJDBCmysql {
   
   private static void affiche(String message) {
      System.out.println(message);
   }

   private static void arret(String message) {
      System.err.println(message);
      System.exit(99);
   }

   public static void main(java.lang.String[] args) {
      Connection con=null;
      ResultSet resultats=null;
      String requete = "";
      // chargement du pilote
      try {
         Class.forName("com.mysql.cj.jdbc.Driver");
      } catch (ClassNotFoundException e) {
         e.printStackTrace();
         arret("Impossible de charger le pilote jdbc:odbc");
      }

      // connection a la base de donnees

      affiche("connection a la base de donnees");
      try {
          String DBurl = "jdbc:mysql://localhost:3306/instr_collection";
      String username="user";
      String password="password";
          con = DriverManager.getConnection(DBurl, username, password);
      } catch (SQLException e) {
      e.printStackTrace();
          arret("Connection a la base de donnees impossible");
      }

      // insertio d'un enregistrement dans la table instruments
      affiche("creation enregistrement");

      requete = "INSERT INTO instruments VALUES(3,'hautbois)";
      try {
         Statement stmt = con.createStatement();
         int nbMaj = stmt.executeUpdate(requete);
         affiche("nb mise a jour = "+nbMaj);
      } catch (SQLException e) {
         e.printStackTrace();
      }

      // creation et execution de la requete
      affiche("creation et execution de la requete");
      requete = "SELECT * FROM client";

      try {
         Statement stmt = con.createStatement();
         resultats = stmt.executeQuery(requete);
      } catch (SQLException e) {
     e.printStackTrace();
         //arret("Anomalie lors de l'execution de la requete");
      }

      // parcours de donnes retournees
      affiche("parcours des donnees retournees");
      try {
         ResultSetMetaData rsmd = resultats.getMetaData();
         int nbCols = rsmd.getColumnCount();
         boolean encore = resultats.next();

         while (encore) {
        
            for (int i=1; i <= nbCols; i++) 
               System.out.print(resultats.getString(i) + " ");
            System.out.println();
            encore = resultats.next();

          }

          resultats.close();
      } catch (SQLException e) {
      e.printStackTrace();
          //arret(e.getMessage());
      }

      affiche("fin de programme");
      System.exit(0);
   }
}

and pom.xml

    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.company.driver</groupId>
  <artifactId>mysql-odbc</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>mysql-odbc</name>
  <url>http://maven.apache.org</url>
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java.version>18</java.version>
    <maven.compiler.source>${java.version}</maven.compiler.source>
    <maven.compiler.target>${java.version}</maven.compiler.target>
    <maven.surefire.version>2.22.2</maven.surefire.version>
    <junit.jupiter.version>5.3.1</junit.jupiter.version>
    <junit.platform.version>1.9.0</junit.platform.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-engine</artifactId>
      <version>${junit.jupiter.version}</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-api</artifactId>
      <version>${junit.jupiter.version}</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.junit.platform</groupId>
      <artifactId>junit-platform-commons</artifactId>
      <version>${junit.platform.version}</version>
      <scope>test</scope>
    </dependency>    
    <dependency>
      <groupId>org.junit.platform</groupId>
      <artifactId>junit-platform-commons</artifactId>
      <version>${junit.platform.version}</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-params</artifactId>
      <version>${junit.jupiter.version}</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.junit.platform</groupId>
      <artifactId>junit-platform-suite</artifactId>
      <version>${junit.platform.version}</version>
      <scope>test</scope>
    </dependency>    
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.18</version>
    </dependency>
    </dependencies>   
    <build>
        <finalName>maven-unit-test</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
                <version>${maven.surefire.version}</version>
                <configuration>
            <forkCount>0</forkCount>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

I have searched what could be wrong, may be the classpath for the loading of the driver but now I think I have set it correctly. I could try to install manually the J-connector but I am not experimented with this.