Dagger is a compile-time dependency injection framework for Java and Android applications. It automates the construction and wiring of object graphs by generating static source code during the build process, which eliminates the need for reflection or runtime bytecode generation.
The framework distinguishes itself by performing strict validation of the entire dependency structure before the application runs, ensuring that all required bindings are satisfied and identifying circular references early. It manages object lifecycles through scoped containers and supports lazy resolution, allowing developers to defer the instantiation of resources until they are explicitly requested.
The system provides comprehensive tools for managing complex object graphs, including support for environment-specific configurations, assisted injection, and the ability to swap production components with test-specific implementations. It also facilitates the aggregation of related objects and handles optional dependencies, providing a structured approach to resource allocation and memory management.
