import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/api/users")
public class UserController {

    @PostMapping
    public ResponseEntity<User> createUser(@RequestBody User user) {
        // 保存用戶邏輯（假設(shè)已成功保存）
        user.setId(1L); // 假設(shè)生成的用戶ID為1

        // 設(shè)置 Location 頭指向新資源的 URI
        HttpHeaders headers = new HttpHeaders();
        headers.setLocation(ServletUriComponentsBuilder
                .fromCurrentRequest()
                .path("/{id}")
                .buildAndExpand(user.getId())
                .toUri());

        return new ResponseEntity<>(user, headers, HttpStatus.CREATED); // 201 Created
    }
}

@GetMapping("/{id}")
public ResponseEntity<User> getUser(@PathVariable Long id) {
    User user = userService.findById(id); // 假設(shè)用戶存在
    HttpHeaders headers = new HttpHeaders();
    headers.setCacheControl(CacheControl.noCache()); // 禁止緩存

    return new ResponseEntity<>(user, headers, HttpStatus.OK); // 200 OK
}

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;

@ResponseStatus(code = HttpStatus.NOT_FOUND, reason = "User not found")
public class UserNotFoundException extends RuntimeException {
    public UserNotFoundException(String message) {
        super(message);
    }
}

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(UserNotFoundException.class)
    public ResponseEntity<ErrorDetails> handleUserNotFound(
            UserNotFoundException ex, WebRequest request) {
        ErrorDetails error = new ErrorDetails(
                HttpStatus.NOT_FOUND.value(),
                ex.getMessage(),
                request.getDescription(false)
        );
        return new ResponseEntity<>(error, HttpStatus.NOT_FOUND);
    }

    @ExceptionHandler(Exception.class)
    public ResponseEntity<ErrorDetails> handleGeneralException(
            Exception ex, WebRequest request) {
        ErrorDetails error = new ErrorDetails(
                HttpStatus.INTERNAL_SERVER_ERROR.value(),
                "Internal Server Error",
                request.getDescription(false)
        );
        return new ResponseEntity<>(error, HttpStatus.INTERNAL_SERVER_ERROR);
    }

    // 輔助類：錯(cuò)誤響應(yīng)體
    private static class ErrorDetails {
        private int statusCode;
        private String message;
        private String path;

        public ErrorDetails(int statusCode, String message, String path) {
            this.statusCode = statusCode;
            this.message = message;
            this.path = path;
        }
        // 省略 getter/setter
    }
}

@GetMapping("/custom-headers")
public ResponseEntity<String> customHeaders() {
    HttpHeaders headers = new HttpHeaders();
    headers.add("X-Custom-Header", "custom-value");
    headers.set("Content-Type", "text/plain");
    headers.set("Access-Control-Allow-Origin", "*");
    return new ResponseEntity<>("Response with custom headers", headers, HttpStatus.OK);
}