SpringMVC通过注解实现全局异常处理问题小结

// 用户未找到异常
public class UserNotFoundException extends RuntimeException {
    public UserNotFoundException() {
        super();
    }
    public UserNotFoundException(String message) {
        super(message);
    }
}
// 数据验证异常
public class ValidationException extends RuntimeException {
    public ValidationException(String message) {
        super(message);
    }
}

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;
// 全局异常处理器，会拦截所有控制器抛出的异常
@ControllerAdvice
public class GlobalExceptionHandler {
    // 处理用户未找到异常
    @ExceptionHandler(UserNotFoundException.class)
    @ResponseBody  // 将返回结果转换为JSON
    @ResponseStatus(HttpStatus.NOT_FOUND)  // 设置HTTP状态码为404
    public Result<Void> handleUserNotFoundException(UserNotFoundException e) {
        return Result.error(404, e.getMessage());
    }
    // 处理数据验证异常
    @ExceptionHandler(ValidationException.class)
    @ResponseBody
    @ResponseStatus(HttpStatus.BAD_REQUEST)  // 设置HTTP状态码为400
    public Result<Void> handleValidationException(ValidationException e) {
        return Result.error(400, e.getMessage());
    }
    // 处理其他未捕获的异常
    @ExceptionHandler(Exception.class)
    @ResponseBody
    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)  // 设置HTTP状态码为500
    public Result<Void> handleOtherExceptions(Exception e) {
        // 实际项目中可以在这里记录日志
        return Result.error(500, "服务器内部错误：" + e.getMessage());
    }
}

@RestController
@RequestMapping("/users")
public class UserController {
    @Autowired
    private UserService userService;
    @GetMapping("/{id}")
    public Result<User> getUser(@PathVariable Long id) {
        // 这里不再需要try-catch，异常会被全局异常处理器捕获
        User user = userService.getUserById(id);
        if (user == null) {
            throw new UserNotFoundException("用户不存在，ID: " + id);
        }
        return Result.success(user);
    }
    @PostMapping
    public Result<User> createUser(@RequestBody User user) {
        if (user.getName() == null || user.getName().isEmpty()) {
            throw new ValidationException("用户名不能为空");
        }
        User savedUser = userService.saveUser(user);
        return Result.success(savedUser);
    }
}

@ExceptionHandler(Exception.class)
public Result<Void> handleOtherExceptions(Exception e) {
    log.error("发生未捕获异常", e);  // 记录异常日志
    return Result.error(500, "服务器内部错误");
}