Spring Boot includes auto-configuration based on the starter's JAR, which is available on the classpath of the Spring application. Spring Boot POMs has dependencies on the Starters, so you can override dependency versions by setting the appropriate Maven property in your pom.xml like this:

<properties> 
   <spring.version>5.0.0.RELEASE</spring.version> 
</properties> 

There are good reasons to override dependency version sometimes, such as a bug in the given version, or your company policies. Ideally, you should avoid changing a dependency version because it makes your life more complicated as you won't be able to manage the version's transitive dependencies in your application.

If some libraries don't suit your Spring application, you could exclude them from the classpath of the Spring application. Let's see the following example:

<dependency> 
   <groupId>org.springframework.boot</groupId> 
   <artifactId>spring-boot-starter-websocket</artifactId> 
   <exclusions> 
         <exclusion> 
               <groupId>ch.qos.logback</groupId> 
               <artifactId>logback-classic</artifactId> 
         </exclusion> 
   </exclusions> 
</dependency> 
 
<dependency> 
   <groupId>org.slf4j</groupId> 
   <artifactId>slf4j-log4j12</artifactId> 
</dependency> 

As you can see, I have excluded the default logback library from the spring-boot-starter-websocket starter and added the log4j library for application logging.

Let's move to another section about customizing configuration of Spring Boot.