@ConfigurationProperties & @EnableConfigurationProperties

Simply put, @EnableConfigurationProperties is acted like a general switch, enabling or disabling (by absense) Spring Boot’s functionality to bind a certain properties from the environment to a pojo class, and @ConfigurationProperties is used on the said pojo, as the receiver of environmental properties.

These two annotations should be both used at the same time in combinations in a project, as follows:

1. on the app’s configuration class:

   @SpringBootApplication
   @EnableConfigurationProperties
   public class SpringBootWebApplication {...}

   and one the pojo

   @Component
   @ConfigurationProperties
   public class TestConfig {}

In this case, @EnableConfigurationProperties enables the functionality app-wise, and the config pojo registers itself with the help of @Component.

2.
on the app’s configuration class:

@SpringBootApplication
@EnableConfigurationProperties(TestConfig.class)
public class SpringBootWebApplication {...}

and one the pojo

@ConfigurationProperties
public class TestConfig {}

In this case, @EnableConfigurationProperties not only enables the functionality, but also selects a config pojo to be used in this project. The config pojo (TestConfig) doesn’t have to register itself through @Component.