From ee5e48472c037c2e3e1ec37b3c262c699255be62 Mon Sep 17 00:00:00 2001 From: Otavio Santana Date: Sat, 2 Sep 2023 13:28:09 +0100 Subject: [PATCH] docs: create CDI and jax-rs documentation Signed-off-by: Otavio Santana --- docs/jakarta-ee/cdi.md | 44 +++++++++++++++++++++++++++++++++++++++ docs/jakarta-ee/jax-rs.md | 38 +++++++++++++++++++++++++++++++++ 2 files changed, 82 insertions(+) create mode 100644 docs/jakarta-ee/cdi.md diff --git a/docs/jakarta-ee/cdi.md b/docs/jakarta-ee/cdi.md new file mode 100644 index 0000000..6544421 --- /dev/null +++ b/docs/jakarta-ee/cdi.md @@ -0,0 +1,44 @@ +# CDI + +In our journey toward seamlessly integrating Java with NoSQL databases for modern applications, we come across an indispensable tool called CDI, or Contexts and Dependency Injection. CDI is more than just an acronym; it represents a paradigm shift in managing dependencies, promoting reusability, and elevating Object-Oriented Programming (OOP) to new heights in enterprise development. + +At its core, CDI is a specification within the Jakarta EE ecosystem that simplifies how we create, manage, and inject dependencies in our Java applications. It allows us to embrace the principles of Inversion of Control (IoC) and Dependency Injection (DI), pivotal in developing robust, modular, and maintainable code. + +You might wonder, "Why is CDI so crucial when working with NoSQL databases in modern applications?" Let's explore a few compelling reasons: + +**1. Decoupling and Flexibility:** CDI enables us to decouple components, making our applications more flexible and adaptable. This flexibility becomes paramount when integrating with NoSQL databases, which often involve handling diverse data models. CDI allows us to swap out database implementations or adapt to schema changes with minimal impact on the rest of our application. + +**2. Scalability and Testability:** Modern applications demand scalability and robust testing. CDI promotes using design patterns like Singleton, which are instrumental in managing resources efficiently and achieving scalability. Additionally, it simplifies the testing process by allowing us to easily replace real implementations with mock objects during unit testing, ensuring our code is reliable and maintainable. + +**3. Enhanced Object-Oriented Programming:** CDI takes the principles of OOP to another level. It encourages the use of well-defined interfaces, key to building modular and reusable components. By adhering to CDI practices, we can create cleaner, more understandable code that's easier to extend and maintain. + +**4. Loose Coupling:** CDI promotes loose Coupling between components. In the context of NoSQL integration, where database structures can evolve rapidly, this loose Coupling ensures that changes to the database schema don't ripple through the entire application. We can adapt our data access components independently, avoiding cascading changes and reducing the risk of bugs. + + +## CDI Scope + + +| CDI Scope | Description | +|-----------------------------|-------------------------------------------------------| +| **Dependent** | The shortest-lived scope, tied to the lifecycle of the bean that declares it. Dependent beans are created and destroyed each time they are injected or requested. | +| **Request** | Scoped to an HTTP request in a web application. The bean instance is created for the duration of an HTTP request and destroyed when the request is completed. | +| **Session** | Scoped to an HTTP session in a web application. The bean instance is created when the session is initiated and destroyed when the session ends. | +| **Application** | Scoped to the entire lifecycle of the application. The bean instance is created when the application starts and destroyed when the application is shut down. | +| **Conversation** | Scoped to a long-running conversation in a web application. It spans multiple HTTP requests and allows maintaining conversational state. The bean instance is created at the beginning of a conversation and destroyed when the conversation ends. | +| **Singleton** | Scoped to a single, shared instance across the entire application. The same bean instance is reused for all clients, promoting global state and sharing among components. | + + +These CDI scopes provide a powerful mechanism for managing the lifecycle and visibility of beans in your application, allowing you to control how and when dependencies are created and maintained. The choice of scope depends on the specific requirements of your application and how you want to manage bean instances and their interactions. + + +## The main CDI (Contexts and Dependency Injection) feature with brief descriptions: + +| CDI Feature | Description | +|----------------------------|-------------------------------------------------------| +| **Dependency Injection** | Automatic injection of dependencies into components, simplifying the management of resources like NoSQL database clients or DAOs. | +| **Scopes** | Definition of bean lifecycles, allowing you to manage the duration and visibility of beans, such as NoSQL database connections. | +| **Interceptors** | Creation of interceptors to apply cross-cutting concerns (e.g., logging, security) to methods, enhancing NoSQL database access logic. | +| **Alternatives** | Configuration of alternative bean implementations, facilitating the flexibility to switch between different NoSQL database providers or configurations. | +| **Producers** | Implementation of producer methods to dynamically create and manage instances of beans, including NoSQL database connections. | +| **Event** | CDI's event mechanism enables communication between loosely coupled components by allowing one component to fire events and others to observe and react to them. This can be used to trigger actions based on NoSQL database changes or updates. | + diff --git a/docs/jakarta-ee/jax-rs.md b/docs/jakarta-ee/jax-rs.md index 73ec6aa..251b73c 100644 --- a/docs/jakarta-ee/jax-rs.md +++ b/docs/jakarta-ee/jax-rs.md @@ -1 +1,39 @@ # JAX-RS + + +Java API for RESTful Web Services (JAX-RS) plays a pivotal role in the modern landscape of NoSQL databases. Its importance lies in providing a standardized and efficient way to build, expose, and consume RESTful APIs, aligning seamlessly with the principles and requirements of NoSQL databases. Here's why JAX-RS is indispensable in the NoSQL database ecosystem: + +1. **RESTful Communication**: NoSQL databases often rely on a RESTful architecture for data access and manipulation. JAX-RS provides a standardized and easy-to-understand way to design RESTful APIs, enabling applications to communicate with NoSQL databases over HTTP using well-defined endpoints. + +2. **Simplified Integration**: JAX-RS simplifies the integration process between applications and NoSQL databases. Providing a uniform and language-agnostic approach to API development removes the complexities of underlying database technologies, making it easier to work with diverse NoSQL solutions. + +3. **Scalability**: NoSQL databases are known for their scalability, and JAX-RS aligns perfectly with this characteristic. It allows you to design scalable, stateless APIs that can handle a high volume of requests, making it suitable for applications with rapidly growing data needs. + +4. **Flexibility**: NoSQL databases often cater to various data models (e.g., document, key-value, column-family), and JAX-RS accommodates this flexibility. You can design APIs that support diverse data structures, making it adaptable to the ever-changing schema requirements of NoSQL databases. + +5. **Cross-Platform Compatibility**: JAX-RS is not limited to Java-only environments. It facilitates Communication between Java applications and NoSQL databases while remaining compatible with various programming languages and platforms, promoting interoperability. + +6. **Security**: Security is a paramount concern when interacting with NoSQL databases, and JAX-RS provides features for authentication, authorization, and secure Communication, ensuring that sensitive data in NoSQL databases is protected. + +7. **Community and Tooling**: JAX-RS benefits from a vibrant development community and many tools and libraries that simplify API development and testing. This ecosystem is invaluable when building applications that interact with NoSQL databases. + + +## JAX-RS annotations + +| Annotation | Description | +|------------------------|---------------------------------------------------| +| `@Path` | Specifies the base URI path for a resource or resource method, allowing the mapping of HTTP requests to specific endpoints. | +| `@GET` | Indicates that a method handles HTTP GET requests, retrieving resource representations or data. | +| `@POST` | Marks a method to handle HTTP POST requests, typically used for creating or submitting data to the server. | +| `@PUT` | Designates a method to handle HTTP PUT requests, used for updating or replacing a resource's state. | +| `@DELETE` | Specifies that a method is responsible for handling HTTP DELETE requests, removing a resource from the server. | +| `@PathParam` | Retrieves values from URI path parameters and injects them into resource method parameters. | +| `@QueryParam` | Extracts values from query parameters in the URI and injects them into resource method parameters. | +| `@FormParam` | Reads data from HTML form submissions and injects it into resource method parameters. | +| `@Produces` | Specifies the media types (e.g., JSON, XML) that a resource method can produce as a response. | +| `@Consumes` | Indicates the media types that a resource method can accept as input data. | +| `@HeaderParam` | Extracts values from HTTP headers and injects them into resource method parameters. | +| `@Context` | Allows injection of context-specific objects (e.g., `UriInfo`, `HttpServletRequest`) into resource classes or methods. | +| `@Provider` | Marks a class as a JAX-RS provider, which can handle custom processing for request or response entities, exceptions, and other aspects of RESTful services. | + +These annotations are fundamental when building RESTful APIs using JAX-RS, enabling you to define resource endpoints, HTTP methods, parameter handling, media types, and more, ultimately creating robust and interoperable web services. \ No newline at end of file