The spring-boot-starter-parent dependency inherits from spring-boot-dependencies, which is defined at the top of the POM. The following code snippet shows an extract from spring-boot-starter-parent:

    <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-dependencies</artifactId>
      <version>2.0.0.M1</version>
      <relativePath>../../spring-boot-dependencies</relativePath>
   </parent>

The spring-boot-dependencies provides default dependency management for all the dependencies that Spring Boot uses. The following code shows the different versions of various dependencies that are configured in spring-boot-dependencies:

<activemq.version>5.13.4</activemq.version>
<aspectj.version>1.8.9</aspectj.version>
<ehcache.version>2.10.2.2.21</ehcache.version>
<elasticsearch.version>2.3.4</elasticsearch.version>
<gson.version>2.7</gson.version>
<h2.version>1.4.192</h2.version>
<hazelcast.version>3.6.4</hazelcast.version>
<hibernate.version>5.0.9.Final</hibernate.version>
<hibernate-validator.version>5.2.4.Final</hibernate
  validator.version>
<hsqldb.version>2.3.3</hsqldb.version>
<htmlunit.version>2.21</htmlunit.version>
<jackson.version>2.8.1</jackson.version>
<jersey.version>2.23.1</jersey.version>
<jetty.version>9.3.11.v20160721</jetty.version>
<junit.version>4.12</junit.version>
<mockito.version>1.10.19</mockito.version>
<selenium.version>2.53.1</selenium.version>
<servlet-api.version>3.1.0</servlet-api.version>
<spring.version>4.3.2.RELEASE</spring.version>
<spring-amqp.version>1.6.1.RELEASE</spring-amqp.version>
<spring-batch.version>3.0.7.RELEASE</spring-batch.version>
<spring-data-releasetrain.version>Hopper-SR2</spring-
  data-releasetrain.version>
<spring-hateoas.version>0.20.0.RELEASE</spring-hateoas.version>
<spring-restdocs.version>1.1.1.RELEASE</spring-restdocs.version>
<spring-security.version>4.1.1.RELEASE</spring-security.version>
<spring-session.version>1.2.1.RELEASE</spring-session.version>
<spring-ws.version>2.3.0.RELEASE</spring-ws.version>
<thymeleaf.version>2.1.5.RELEASE</thymeleaf.version>
<tomcat.version>8.5.4</tomcat.version>
<xml-apis.version>1.4.01</xml-apis.version>

If we want to override a specific version of a dependency, we can do that by providing a property with the right name in the pom.xml file of our application. The following code snippet shows an example of configuring our application to use version 1.10.20 of Mockito:

    <properties>
     <mockito.version>1.10.20</mockito.version>
    </properties>

The following are some of the other things defined in spring-boot-starter-parent:

• The default Java version <java.version>1.8</java.version>
• The default configuration for Maven plugins:
  • maven-failsafe-plugin
  • maven-surefire-plugin
  • git-commit-id-plugin

Compatibility between different versions of frameworks is one of the major problems faced by developers. How do I find the latest Spring Session version that is compatible with a specific version of Spring? The usual answer would be to read the documentation. However, if we use Spring Boot, this is made simple by spring-boot-starter-parent. If we want to upgrade to a newer Spring version, all that we need to do is to find the spring-boot-starter-parent dependency for that Spring version. Once we upgrade our application to use that specific version of spring-boot-starter-parent, we would have all the other dependencies upgraded to the versions compatible with the new Spring version. One less problem for developers to handle. Always make me happy.