java - Spring Boot with redirecting with single page angular2

Question

I have a single page Angular app with Spring Boot. It looks like the following:

src
  main
  java
    controller
       HomeController
       CustomerController
       OtherController
  webapp
    js/angular-files.js
    index.html

Spring boot correctly defaults to webapp folder and serves index.html file.

What I am looking to do is:

1. For every local REST request not starting with /api overwrite and redirect to default webapp/index.html. I plan to serve anything /api to the spring controllers.

2. Is there a way to prefix all controllers with API so that I do not have to write API every time? e.g.

   @RequestMapping("/api/home") can write shorthand in code @RequestMapping("/home")

or

@RequestMapping("/api/other-controller/:id") can write shorthand  @RequestMapping("/other-controller/:id")

I'm looking for every API request, e.g. 1) http://localhost:8080/api/home keep API with API and resolve to correct controller and return JSON, however if someone enters a URL like http:///localhost/some-url or http:///localhost/some-other/123/url then it will serve the index.html page and keep the URL.

Alternative ways to do it: try adding #ErrorViewResolver: Springboot/Angular2 - How to handle HTML5 urls?

Answer 1

If you're tired of trying to solve this problem by following so many conflicting solutions - look here!!

After hours upon hours trying to follow all the scattered advice from dozens of stack overflow and blog posts, I've finally found the minimum PURE spring boot + angular 6 application to always redirect to index.html after a refresh on a non-root page WHILE maintaining all your REST API endpoint paths. No @EnableWebMvc, no @ControllerAdvice, no changes to application.properties, no custom ResourceHandlerRegistry modifications, just simplicity:

Very important pre-requisite

You *must* include the output of ng build into Spring's resources/static folder. You can accomplish this via the maven-resources-plugin. Learn here: Copying multiple resource directories to independent target directories with maven

Code

@Controller
@SpringBootApplication
public class MyApp implements ErrorController {

    public static void main(String[] args) {
        SpringApplication.run(MyApp.class, args);
    }

    private static final String PATH = "/error";

    @RequestMapping(value = PATH)
    public String error() {
        return "forward:/index.html";
    }

    @Override
    public String getErrorPath() {
        return PATH;
    }
}

Reasoning

• Including the output of ng-build into resources/static at build time allows spring view redirects ("forward:/index.html") to succeed. It seems spring cannot redirect to anything outside of the resources folder so if you're trying to access pages at the root of the site, it won't work.
• With default functionality (i.e. no additions of @EnableWebMvc or changes to application.properties) navigating to / automatically serves the index.html (iff it was included in the resources/static folder) so no need to make changes there.
• With default functionality (as stated above), any error encountered in a spring boot app routes to /error and implementing ErrorController overrides that behavior to - you guessed it - route to index.html which allows Angular to take over the routing.

Remarks

• Don't settle for the HashLocationStrategy to get over this problem as it is not recommended by Angular: https://angular.io/guide/router#which-strategy-is-best