BeanRepository - Dependency Injection / Service Locator

This framework is the implementation of a mix of the Service Locator Pattern and a the Dependency Injection Pattern. These patterns are described by Martin Fowler in this article. The BeanRepository does not use reflection for injecting beans. Because of that fact, it can be used in the Java sandbox, where reflection is not allowed.

Features

• simple, self-explanatory and failsafe configuration in Java code
• no use of reflection or annotations
• constructor injection
• support for singletons, prototypes and instances
• provider
• factories
• aliases for beans
• fail fast on start up
• execute code after initialisation of the bean (post construct)
• configurable if singletons are lazy initialised or not
• detect beans of a specific type
• modularity possible

Limitations

• cyclic references not supported directly. But if needed, see CyclicReferenceExampleApp for a solution
• no request or session scope
• no initialisation code allowed in constructor
  • constructor may be called multiple times while working with the BeanRepository
• a bean can only be accessed by a class

Maven

Include the following artifact to use the BeanRepository:

<dependency>
    <groupId>com.github.tinosteinort</groupId>
    <artifactId>beanrepository</artifactId>
    <version>1.7.0</version>
</dependency>

Examples

See SimpleExampleApp for ar very basic example.

See EventExampleApp for an example with events and listeners.

See CyclicReferenceExampleApp for an example with cyclic references.

Version History

v1.7.0

Enhancements:

• Introduce BeanRepositoryApplication
• Add examples

Fixes:

• Issue#4: onPostConstruct of singleton beans is executed if the bean is requested, not when the BeanRepository is build
• Issue#5: onPostConstruct of a Factory Bean is not triggered

v1.6.0

Enhancements:

• Aliases for beans

v1.5.1

Fixes:

• Issue#3: StackOverflowError when using PostConstructible in Combination with ConstructorInjection

v1.5.0

Fixes:

• Issue#2: getProvidersForSingletons() does not consider Factories

Enhancements:

• Issue#1: Method should be private, not for external use
• Support simple Access to Prototype Beans with Parameter (with and without Dependencies to other Beans)

v1.4.0

Fixes:

• Modularisation does not work as expected. Concept refactored.

Enhancements:

• Constructor Injection

v1.3.1

Fixes:

• Factory.createInstance() is not called while dryRun. It is executed once for singleton Beans, and every time, when a prototype Bean is requested

v1.3.0

Enhancements:

• A Factory can be used to create Beans

v1.2.0

Enhancements:

• Add Provider Interface, and Methods to get Providers for registered Beans

v1.1

Fixes:

• onPostConstruct was called multiple Times on referenced Beans

Enhancements:

• Add other getBean(...) Methods to BeanAccessor. This allows to generate prototype Beans in a Constructor

v1.0

Initial Version