Developing Java Applications with Spring and Spring Boot

Getting ready

In our previous example, we created the basic application that will execute a command-line runner by printing a message in the logs. Let's enhance this application by adding a connection to a database.

Earlier, we already added the necessary jdbc and data-jpa starters as well as an H2 database dependency to our build file. Now we will configure an in-memory instance of the H2 database.

In the case of an embedded database, such as H2, Hyper SQL Database (HSQLDB), or Derby, no actual configuration is required besides including the dependency on one of these in the build file. When one of these databases is detected in the classpath and a DataSource bean dependency is declared in the code, Spring Boot will automatically create ...