How to add multiple RestController endpoints differed by query-params?

• Use @RequestParam to extract query parameters
• Add parameter for @RequestParam: value, defaultValue, required

with java >= 8:

@RestController
public class PersonController {
     @GetMapping("/persons")
     public String personList(@RequestParam(value = "sort", defaultValue = "name") Optional<String> sort) {
         //handling process here
     }
}

with java < 8:

@RestController
public class PersonController {
     @GetMapping("/persons")
     public String personList(@RequestParam(value = "sort", defaultValue = "name", required=false) String sort) {
         //handling process here
     }
}

You could use @GetMapping.params

@GetMapping(value = "/persons", params = "sort")
public String sorted() {

You can use the params element. One mapping will supports params="sort" for when the sort parameter is present and the other params="!sort" for when it is missing.

However, you may want to consider using a default value instead of performing a redirect. What benefit does the redirect provide? It will require the server respond and then and have the client make a second HTTP request.

Using params

@RestController
public class PersonController {
    //only in case the "sort" query parameter is missing
    @GetMapping(value = "/persons", params = "!sort")
    public String unsorted() {
         return "redirect:/persons?sort=name";
    }

    //only in case the "sort" query parameter exists
    @GetMapping(value = "/persons", params = "sort")
    public String sorted() {
         //...
    }
}

Using default value

@RestController
public class PersonController {

    //only in case the "sort" query parameter exists
    @GetMapping("/persons")
    public String sorted(
        @RequestParam(name = "sort", defaultValue = "name") String sort)
    {
         //...
    }
}

You can set a default value:

@RestController
public class PersonController {
    //only in case the "sort" query parameter is missing
    @GetMapping("/persons")
    public String unsorted(@RequestParam(value = "sort", defaultValue = "name") String name) {
        // do logic
    }
}

You can also set the default value for the missing value and continue forward

@RequestParam(value = "sort", defaultValue = "name") String name