spring - PropertySourcesPlaceholderConfigurer not registering with Environment in a SpringBoot Project - Stack Overflow

spring - PropertySourcesPlaceholderConfigurer not registering with Environment in a SpringBoot Project - Stack Overflow

The issue here is the distinction between PropertySourcesPlaceholderConfigurer and StandardServletEnvironment, or Environment for simplicity.

The Environment is an object that backs the whole ApplicationContext and can resolve a bunch of properties (the Environment interface extends PropertyResolver). A ConfigurableEnvironment has a MutablePropertySources object which you can retrieve through getPropertySources(). This MutablePropertySources holds a LinkedList of PropertySource objects which are checked in order to resolve a requested property.

PropertySourcesPlaceholderConfigurer is a separate object with its own state. It holds its own MutablePropertySources object for resolving property placeholders. PropertySourcesPlaceholderConfigurer implements EnvironmentAware so when the ApplicationContext gets hold of it, it gives it its Environment object. The PropertySourcesPlaceholderConfigurer adds this Environment's MutablePropertySources to its own. It then also adds the various Resource objects you specified with setLocation() as additional properties. These Resource objects are not added to the Environment's MutablePropertySources and therefore aren't available with env.getProperty(String).

So you cannot get the properties loaded by the PropertySourcesPlaceholderConfigurer into the Environment directly. What you can do instead is add directly to the Environment's MutablePropertySouces

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