Annotate Conditional Field License For Free

To conditionally create a bean, we must first create an implementation of Condition. The Condition interface contains the matches method which returns a boolean value. Here, the AuditEnabledCondition class is checking whether audit. enabled is true using the Environment properties.

Annotation Interface ConditionalOnMissingBean. @Conditional that only matches when no beans meeting the specified requirements are already contained in the BeanFactory . None of the requirements must be met for the condition to match and the requirements do not have to be met by the same bean.

The @ConditionalOnProperty annotation in Spring allows us to instantiate a component based a given condition. For example we could instantiate an implementation or another depending on a configuration property.

It allows you to setup features based upon certain conditions like presence of a class in classparth or a JAR File which is how Spring Boot Auto-configuration works. The majority of @Conditional annotation users are, Conditions based on Bean definition or object present in the application.

Why do we need Conditional Beans? A Spring application context contains an object graph that makes up all the beans that our application needs at runtime. Spring's @Conditional annotation allows us to define conditions under which a certain bean is included into that object graph.

In this tutorial, we'll take a look at the @Conditional annotation. It's used to indicate whether a given component is eligible for registration based on a defined condition.

The Spring framework provides the @ConditionalOnProperty annotation precisely for this purpose. In short, the @ConditionalOnProperty enables bean registration only if an environment property is present and has a specific value. By default, the specified property must be defined and not equal to false.