errors in the oreilly book and this source code

[knail1]

In the O'reilly book you initiate the spring-boot project like so:
spring init --build maven --groupId com.redhat.examples --version 1.0 --java-version 1.8 --dependencies web --name hola-springboot hola-springboot

This sets up the project under com.redhat.examples.hola-springboot/*

however, in this source code, your package has been created under
com.example/*

so clearly you initialized our spring project differently when you created this source code compared to your instructions in the book.