Assembling via Spring's Classpath Scanning

If we use the Spring framework to assemble our application, the result is called the “application context”. The application context contains all objects that together make up the application (“beans” in Java lingo).

Spring offers several approaches to assemble an application context and each has its own advantages and drawbacks. Let’s start with discussing the most popular (and most convenient) approach: classpath scanning.

Classpath scanning

With classpath scanning, Spring goes through all classes that are available in the classpath and searches for classes that are annotated with the @Component annotation. The framework then creates an object from each of these classes. The classes should have a constructor that takes all required fields as an argument, like our AccountPersistenceAdapter from the chapter “Implementing a Persistence Adapter”: