ResponseEntity represents the whole HTTP response: status code, headers, and body. As a result, we can use it to fully configure the HTTP response.
If we want to use it, we have to return it from the endpoint; Spring takes care of the rest.
ResponseEntity is a generic type. Consequently, we can use any type as the response body:
1 2 3 4 | @GetMapping("/hello")ResponseEntity<String> hello() { return new ResponseEntity<>("Hello World!", HttpStatus.OK);} |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | @GetMapping("/age")ResponseEntity<String> age( @RequestParam("yearOfBirth") int yearOfBirth) { if (isInFuture(yearOfBirth)) { return new ResponseEntity<>( "Year of birth cannot be in the future", HttpStatus.BAD_REQUEST); } return new ResponseEntity<>( "Your age is " + calculateAge(yearOfBirth), HttpStatus.OK);} |
Additionally, we can set HTTP headers:
1 2 3 4 5 6 7 8 | @GetMapping("/customHeader")ResponseEntity<String> customHeader() { HttpHeaders headers = new HttpHeaders(); headers.add("Custom-Header", "foo"); return new ResponseEntity<>( "Custom header set", headers, HttpStatus.OK);} |
1 2 3 4 | @GetMapping("/hello")ResponseEntity<String> hello() { return ResponseEntity.ok("Hello World!");} |
1 2 3 4 5 6 7 8 9 10 | @GetMapping("/age")ResponseEntity<String> age(@RequestParam("yearOfBirth") int yearOfBirth) { if (isInFuture(yearOfBirth)) { return ResponseEntity.badRequest() .body("Year of birth cannot be in the future"); } return ResponseEntity.status(HttpStatus.OK) .body("Your age is " + calculateAge(yearOfBirth));} |
1 2 3 4 5 6 | @GetMapping("/customHeader")ResponseEntity<String> customHeader() { return ResponseEntity.ok() .header("Custom-Header", "foo") .body("Custom header set");} |