If you want an embedded database (H2, HSQL or Derby), please put it on the classpath.

Sure, if you want to use an embedded database like H2, HSQL, or Derby in your Java application, you need to add the corresponding database driver JAR file to your classpath. The classpath is a set of directories or JAR files that the Java runtime uses to search for classes and resources.

To add a database driver to the classpath, you can follow these steps:

1. Download the database driver JAR file for the desired embedded database (e.g., H2, HSQL, or Derby).
2. Place the JAR file in a directory of your project (e.g., a "lib" folder).
3. If you are using an IDE like Eclipse or IntelliJ IDEA, right-click on the JAR file and select "Build Path" or "Add to Classpath" to include it in your project's build path. Alternatively, you can manually edit the project's build configuration file (e.g., pom.xml for Maven projects) to include the JAR file as a dependency.
4. If you are compiling and running your application from the command line, you can include the JAR file in the classpath using the `-cp` (or `-classpath`) option. For example:

java -cp /path/to/yourproject/lib/driver.jar com.yourpackage.YourMainClass

Replace "/path/to/yourproject/lib/driver.jar" with the actual path to the driver JAR file, and "com.yourpackage.YourMainClass" with the fully qualified name of your main class.

By adding the database driver JAR file to the classpath, you ensure that your application can access the necessary classes and methods to connect and interact with the embedded database.