当我们重新设计企业平台时,我们了解到,使客户不满意的主要因素不是性能或用户界面,而是未修复的故障破坏了流程。 在 Spring Boot 或其他框架中的类似模式中,确保系统在压力下以预期的方式行为,这种纪律类似于更大的领导原则:在发生之前计划失败。 @ControllerAdvice Why This Matters 当您在 REST API 中构建 ,你会很快面对这个问题: Spring Boot “ ” How do I handle errors neatly without writing repetitive try-catch blocks everywhere? 想象有 每个人都可以失败一个 错误的输入或缺失的资源。 而不是返回混乱的堆栈痕迹,你想要 . 50+ endpoints 零指示例外 consistent, meaningful, and client-friendly error responses 这就是哪里 进入 - 它将所有错误处理集中在一个地方。 让我们看看 以实际世界的例子,一步一步地构建这个。 @ControllerAdvice how Use Case — User Management REST API 我们将创建一个 这支持: simple User API 
 
 
 
 
 
 Fetching users 
 
 Creating users 
 
 
 Simulating failures for testing Our goal → build a   that returns clean JSON responses. unified global error-handling layer Step 1: Project Setup Dependencies (Maven): <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-validation</artifactId>
    </dependency>
 This brings in web + validation support. Then create your main app: @SpringBootApplication
public class ExceptionHandlerDemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(ExceptionHandlerDemoApplication.class, args);
    }
}
 Step 2: Define the Entity — User.java @Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private int id;
    @NotBlank(message = "Name cannot be blank")
    private String name;
    @Min(value = 18, message = "Age must be at least 18")
    private int age;
}
 ◎為什麼: ** 我们添加简单的验证,这样 Spring 就可以在输入无效时自动触发方法参数不有效的例外。 Step 3: Custom Exception for Missing Data public class ResourceNotFoundException extends RuntimeException {
    public ResourceNotFoundException(String message) {
        super(message);
    }
}
public class InvalidRequestException extends RuntimeException {
    public InvalidRequestException(String message) {
        super(message);
    }
}
 ◎為什麼: ** 清晰地表示“未找到用户”的情况,而不是通用例外。 Step 4: Build the Controller @RestController
@RequestMapping("/api/users")
public class UserController {
    // Simple GET that throws ResourceNotFoundException for id > 100
    @GetMapping("/{id}")
    public String getUser(@PathVariable("id") @Min(1) Integer id) {
        if (id > 100) {
            throw new ResourceNotFoundException("User with id " + id + " not found");
        }
        return "User-" + id;
    }
    // Create user example to demonstrate validation
    public static record CreateUserRequest(
            @NotBlank(message = "name is required") String name,
            @Min(value = 18, message = "age must be >= 18") int age) {}
    @PostMapping
    @ResponseStatus(HttpStatus.CREATED)
    public String createUser(@RequestBody @Valid CreateUserRequest body) {
        if ("bad".equalsIgnoreCase(body.name())) {
            throw new InvalidRequestException("Name 'bad' is not allowed");
        }
        return "created:" + body.name();
    }
    // Endpoint to force a server error for demo
    @GetMapping("/boom")
    public void boom() {
        throw new IllegalStateException("simulated server error");
    }
}
 ◎為什麼: **我们创建了现实的场景 - 未找到,验证错误和运行时错误 - 我们的全球处理器将管理。 Step 5: Create a Standard Error Model @Data
@AllArgsConstructor
@NoArgsConstructor
public class ErrorResponse {
    private OffsetDateTime timestamp;
    private int status;
    private String error;
    private String message;
    private String path;
    private List<FieldError> fieldErrors;}
 ◎為什麼: **所有API都应该在相同的结构中返回错误 - 这可以改善生产中的监控和调试。 Step 6: Implement @ControllerAdvice (Global Handler) @ControllerAdvice
public class GlobalExceptionHandler {
    private final Logger log = LoggerFactory.getLogger(GlobalExceptionHandler.class);
    // Handle custom validation exceptions
    @ExceptionHandler(InvalidRequestException.class)
    public ResponseEntity<ErrorResponse> handleInvalidRequest(InvalidRequestException ex, HttpServletRequest req) {
        log.debug("InvalidRequestException: {}", ex.getMessage());
        ErrorResponse body = new ErrorResponse(OffsetDateTime.now(), HttpStatus.BAD_REQUEST.value(),
                HttpStatus.BAD_REQUEST.getReasonPhrase(), ex.getMessage(), req.getRequestURI());
        return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(body);
    }
    // Resource not found -> 404
    @ExceptionHandler(ResourceNotFoundException.class)
    public ResponseEntity<ErrorResponse> handleNotFound(ResourceNotFoundException ex, HttpServletRequest req) {
        log.debug("ResourceNotFoundException: {}", ex.getMessage());
        ErrorResponse body = new ErrorResponse(OffsetDateTime.now(), HttpStatus.NOT_FOUND.value(),
                HttpStatus.NOT_FOUND.getReasonPhrase(), ex.getMessage(), req.getRequestURI());
        return ResponseEntity.status(HttpStatus.NOT_FOUND).body(body);
    }
    // Validation errors from @Valid on request bodies
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity<ErrorResponse> handleValidation(MethodArgumentNotValidException ex, HttpServletRequest req) {
        log.debug("Validation failed: {}", ex.getMessage());
        List<ErrorResponse.FieldError> fieldErrors = ex.getBindingResult().getFieldErrors().stream()
                .map(fe -> new ErrorResponse.FieldError(fe.getField(), fe.getRejectedValue(), fe.getDefaultMessage()))
                .collect(Collectors.toList());
        ErrorResponse body = new ErrorResponse(OffsetDateTime.now(), HttpStatus.BAD_REQUEST.value(),
                HttpStatus.BAD_REQUEST.getReasonPhrase(), "Validation failed", req.getRequestURI());
        body.setFieldErrors(fieldErrors);
        return ResponseEntity.badRequest().body(body);
    }
    // Type mismatch for method args (?id=abc)
    @ExceptionHandler(MethodArgumentTypeMismatchException.class)
    public ResponseEntity<ErrorResponse> handleTypeMismatch(MethodArgumentTypeMismatchException ex, HttpServletRequest req) {
        log.debug("Type mismatch: {}", ex.getMessage());
        ErrorResponse body = new ErrorResponse(OffsetDateTime.now(), HttpStatus.BAD_REQUEST.value(),
                HttpStatus.BAD_REQUEST.getReasonPhrase(), ex.getMessage(), req.getRequestURI());
        return ResponseEntity.badRequest().body(body);
    }
    // No handler found (404 for unmatched endpoints)
    @ExceptionHandler(NoHandlerFoundException.class)
    public ResponseEntity<ErrorResponse> handleNoHandler(NoHandlerFoundException ex, HttpServletRequest req) {
        log.debug("NoHandlerFound: {} {}", ex.getHttpMethod(), ex.getRequestURL());
        ErrorResponse body = new ErrorResponse(OffsetDateTime.now(), HttpStatus.NOT_FOUND.value(),
                HttpStatus.NOT_FOUND.getReasonPhrase(), "Endpoint not found", req.getRequestURL().toString());
        return ResponseEntity.status(HttpStatus.NOT_FOUND).body(body);
    }
    // Generic fallback
    @ExceptionHandler(Exception.class)
    public ResponseEntity<ErrorResponse> handleAll(Exception ex, HttpServletRequest req) {
        log.error("Unhandled exception: ", ex);
        ErrorResponse body = new ErrorResponse(OffsetDateTime.now(), HttpStatus.INTERNAL_SERVER_ERROR.value(),
                HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase(), "An internal error occurred", req.getRequestURI());
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(body);
    }
}
 Why: 
 
 
 
 @ControllerAdvice → 在所有控制器中使其全球化。 @ExceptionHandler → 捕捉特定例外类型。 buildResponse() 帮助器将代码保持干净和干净。 Step 7: Test Scenarios   GET /api/users/1 答案代码: 200 - 成功 」 」 GET /api/users/999 答案代码: 404 资源未找到 」 」 Validation Error POST / API / 用户 {"name":"", "age": 15} Response: 」 」 Unexpected Error GET /api/用户 / 蓬勃发展 」 」 Why This Approach Works in Real Projects 
 
 
 
 
 
 
 
 
 
 Problem 
 Solution 
 
 
 
 Too many try-catch blocks 
 Centralized handling with @ControllerAdvice 
 
 
 
 Inconsistent responses 
 Unified ErrorResponse structure 
 
 
 
 Hard to debug 
 Standardized messages with timestamps and paths 
 
 
 
 Client confusion 
 Clear, meaningful messages for each failure type 太多的尝试捕捉块 集中处理 @ControllerAdvice 不一致的回应 统一的错误响应结构 难度 Debug 标准化消息与时间标签和路径 客户混淆 每个失败类型的清晰而有意义的信息 Real-World Usage Scenarios 
 
 
 
 
 银行API:确保验证错误(如无效帐号)不会导致服务崩溃。 电子商务:优雅地处理产品未找到或付款错误。 数据微服务:当输入数据未能验证时返回结构化消息。 API Gateway:跨多个微服务的一致响应。 Final Thoughts 通过结合 @ControllerAdvice、 @ExceptionHandler 和一个简单的错误响应模型,您可以获得: 
 
 
 
 清洁代码 持久的 API 体验 在生产中更容易调试 它是 Spring Boot 开发中最简单但最强大的设计模式之一。

This story contains AI-generated text. The author has used AI either for research, to generate outlines, or write the text itself. 

Walkthroughs, tutorials, guides, and tips. This story will teach you how to do something new or how to do something better.

Read My Stories

該音頻是用故事的原始語言製作的！

设计可靠的 API 系统:使用 Spring Boot 控制器的例外处理

About Author

註釋

標籤

这篇文章刊登在

Related Stories

Floki 的 Valhalla 成为印度环斯里兰卡赛事联合赞助商

架构师指南：构建 AI/ML 数据湖参考架构

HackerNoon Decoded: The Top 10 Countries Where HackerNoon Is the Most Active

创建以用户为中心的加密产品：客户反馈的重要性

Floki 的 Valhalla 成为印度环斯里兰卡赛事联合赞助商

架构师指南：构建 AI/ML 数据湖参考架构

HackerNoon Decoded: The Top 10 Countries Where HackerNoon Is the Most Active

创建以用户为中心的加密产品：客户反馈的重要性

Light-Mode

Classic

Newspaper

Minty

Dark-Mode

Neon Noir

Minty

HN StartUps