Repositório com arquivos JAR's

Link das dependências:

Mchange.c3p0 -> https://mvnrepository.com/artifact/com.mchange/c3p0/0.9.5.4

Mchange.mchange-commons-java -> https://mvnrepository.com/artifact/com.mchange/mchange-commons-java/0.2.16

Se estiver utilizando Maven, basta adicionar essas dependencias no arquivo pom.xml (sem contar a do MySqLConnector que ele também menciona no curso)

    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.17</version>
        </dependency>

        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.5.4</version>
        </dependency>

        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>mchange-commons-java</artifactId>
            <version>0.2.16</version>
        </dependency>

    </dependencies>