什么是RESTful Web服务？如何在SpringBoot中创建一个RESTful Web服务？

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
</dependencies>

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

    @GetMapping("/{id}")
    public ResponseEntity<User> getUser(@PathVariable Long id) {
        // 模拟从数据库获取用户信息
        User user = new User(id, "John Doe", "john.doe@example.com");
        return ResponseEntity.ok(user);  // 返回 HTTP 200 OK 和用户信息
    }

    @PostMapping
    public ResponseEntity<User> createUser(@RequestBody User user) {
        // 模拟创建新用户
        User createdUser = new User(1L, user.getName(), user.getEmail());
        return ResponseEntity.status(HttpStatus.CREATED).body(createdUser);  // 返回 HTTP 201 CREATED
    }

    @PutMapping("/{id}")
    public ResponseEntity<User> updateUser(@PathVariable Long id, @RequestBody User user) {
        // 模拟更新用户信息
        user.setId(id);
        return ResponseEntity.ok(user);  // 返回更新后的用户信息
    }

    @DeleteMapping("/{id}")
    public ResponseEntity<Void> deleteUser(@PathVariable Long id) {
        // 模拟删除用户
        return ResponseEntity.noContent().build();  // 返回 HTTP 204 No Content
    }
}

public class User {
    private Long id;
    private String name;
    private String email;

    // 构造方法、getter、setter
    public User(Long id, String name, String email) {
        this.id = id;
        this.name = name;
        this.email = email;
    }

    // getter 和 setter
}

@SpringBootApplication
public class SpringBootRestApplication {
    public static void main(String[] args) {
        SpringApplication.run(SpringBootRestApplication.class, args);
    }
}

@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(ResourceNotFoundException.class)
    public ResponseEntity<String> handleResourceNotFound(ResourceNotFoundException ex) {
        return ResponseEntity.status(HttpStatus.NOT_FOUND).body(ex.getMessage());
    }
}

<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-boot-starter</artifactId>
    <version>3.0.0</version>
</dependency>

@Configuration
@EnableOpenApi
public class SwaggerConfig {
}