Q1. How do you map HTTP methods in a REST controller?
Use @GetMapping, @PostMapping, @PutMapping, @DeleteMapping, @PatchMapping. Example:
@GetMapping("/users") public List getUsers() { ... }
@PostMapping("/users") public User createUser(@RequestBody User user) { ... }
Q2. What is @RequestBody?
@RequestBody binds the HTTP request body to a Java object. It uses HttpMessageConverter to deserialize the request body (e.g., JSON to object). It's typically used in POST and PUT methods to receive data.
Q3. What is @ResponseBody?
@ResponseBody indicates that a method return value should be written directly to the HTTP response body (using HttpMessageConverter). It's used in traditional @Controller methods, but @RestController makes it implicit.
Q4. How do you handle path variables in REST?
Use @PathVariable to capture values from URI template. Example:
@GetMapping("/users/{id}")
public User getUser(@PathVariable Long id) { ... }
Q5. How do you handle query parameters?
Use @RequestParam. Example:
@GetMapping("/users")
public List getUsers(@RequestParam(defaultValue="1") int page) { ... }