Request or response filters via annotations for forwarding (enabling client side routing) in Quarkus

 It seems like you want to implement client-side routing using Angular on the frontend, and Quarkus on the backend for forwarding or handling API requests. Angular doesn't provide annotations like Java EE frameworks do, but you can achieve client-side routing and call Quarkus APIs using Angular's routing and HTTP client.

Here's a high-level approach to achieving this:

**Client-Side Routing with Angular:**

1. **Set Up Angular Application**: Create an Angular application using the Angular CLI or your preferred method.

2. **Routing Configuration**: Define routing in your Angular application using the Angular Router. You can set up routes and configure route parameters, guards, and resolvers.

   ```typescript

   // Example app-routing.module.ts

   import { NgModule } from '@angular/core';

   import { RouterModule, Routes } from '@angular/router';

   const routes: Routes = [

     { path: 'home', component: HomeComponent },

     { path: 'products', component: ProductsComponent },

     // Add more routes as needed

   ];

   @NgModule({

     imports: [RouterModule.forRoot(routes)],

     exports: [RouterModule]

   })

   export class AppRoutingModule { }

   ```

3. **Route Navigation**: In your Angular components, use the `Router` service to navigate between routes based on user interactions.

   ```typescript

   import { Router } from '@angular/router';

   // Navigate to a route

   this.router.navigate(['/products']);

   ```

**Forwarding API Requests to Quarkus:**

1. **Angular HTTP Client**: Use Angular's `HttpClient` to make HTTP requests to your Quarkus backend. For example, to retrieve data from a Quarkus endpoint:

   ```typescript

   import { Injectable } from '@angular/core';

   import { HttpClient } from '@angular/common/http';

   @Injectable({

     providedIn: 'root'

   })

   export class DataService {

     constructor(private http: HttpClient) { }

     fetchData() {

       return this.http.get('http://quarkus-api-url/data');

     }

   }

   ```

2. **Quarkus API Endpoint**: Implement API endpoints in your Quarkus backend that handle the incoming requests. You can use Quarkus' JAX-RS for this.

   ```java

   import javax.ws.rs.GET;

   import javax.ws.rs.Path;

   import javax.ws.rs.core.Response;

   @Path("/data")

   public class DataResource {

       @GET

       public Response getData() {

           // Your data retrieval logic

           return Response.ok("Data from Quarkus").build();

       }

   }

   ```

3. **CORS Configuration**: Ensure that your Quarkus backend is configured to handle Cross-Origin Resource Sharing (CORS) correctly to allow requests from your Angular frontend.

**Client-Side Routing Flow:**

1. A user navigates to a client-side route in your Angular app (e.g., `/products`).

2. Angular's routing mechanism handles the route and loads the associated component.

3. In the Angular component, you use the `HttpClient` to make an HTTP request to a Quarkus API endpoint.

4. Quarkus processes the API request and sends a response back to your Angular app.

5. Angular displays the data retrieved from the Quarkus backend.

This approach enables client-side routing in your Angular app while using Quarkus for handling API requests on the backend.