@GetMapping with array parameters by application.yml

Question

I have developed this @GetMapping RestController and all works fine

@GetMapping(path = {"foo", "bar"})
public ResponseEntity<String> foobar() {
    return ResponseEntity.ok("foobar");
}

now I want externalize the values inside the path array using my application.yml file,so I writed

url:
  - foo
  - bar

and I modified my code in order to use it, but it doesn't work in this two different ways

@GetMapping(path = "${url}")
public ResponseEntity<String> foobar() {
    return ResponseEntity.ok("foobar");
}

@GetMapping(path = {"${url}"})
public ResponseEntity<String> foobar() {
    return ResponseEntity.ok("foobar");
}

I don't understand if the application properties are not correctly formatted or I need to use the SpEL (https://docs.spring.io/spring/docs/3.0.x/reference/expressions.html.

I also want that the code is dynamic according to the application.yml properties, so if the url values increase or decrease the code must still work.

I'm using Springboot 1.5.13

Answer 1

You can't bind YAML list to array or list here. For more information see: @Value and @ConfigurationProperties behave differently when binding to arrays

However, you can achieve this by specifying regular expression in yml file like:

url: '{var:foo|bar}'

And then you can use it directly in your controller:

@GetMapping(path = "${url}")
public ResponseEntity<String> foobar() {
    return ResponseEntity.ok("foobar");
}

Answer 2

You can use in your controller

@GetMapping(path = "${url[0]}")
public ResponseEntity<String> foobar() {
    return ResponseEntity.ok("foobar");
}

@GetMapping(path = {"${url[1]}"})
public ResponseEntity<String> foobar() {
    return ResponseEntity.ok("foobar");
}

Or you can do in this way:

@GetMapping(path = {"${url[0]}","${url[1]}"})
public ResponseEntity<String> foobar() {
    return ResponseEntity.ok("foobar");
}

I think this is helpful