How to hide a bin so that library clients do not see it?

To hide a bean in a Java library and make it invisible to clients, you can use several approaches:

1. Restrict the class scope — make the bean class package-private (without the public modifier), so it is only accessible within the package.

2. Do not export the package (if using Java 9+ modular system) — do not specify the package export in module-info.java.

3. Use Spring configuration — declare the bean inside a configuration class that is not scanned by clients, or use @Bean with limited scope.

4. Use @Component with @Scope and @Lazy — to control the creation and visibility of the bean.

5. Do not include the bean class in the public API of the library — for example, do not place it in public packages or do not provide access through public methods.

Thus, hiding a bean is achieved by restricting the class visibility and the context configuration so that clients cannot directly access or use this bean.