30.springmvc源码学习（三十）@ControllerAdvice 全局异常处理

目录

• 前言
• 一、示例
• 二、原理

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前言

在请求到达了 DispatcherServlet 的处理流程，进入 doDispatch( ) 以及后续流程处理业务的过程中出现异常，会进入到 processDispatchResult( ) 处理异常，此时，如果定义了@ControllerAdvice、@RestControllerAdvice 对应的方法能够处理该异常，则进入对应的方法进行异常处理。

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一、示例

1、返回值结构：

@Data
@ToString(callSuper = true)
@Accessors(chain = true)
@AllArgsConstructor
public class ResponseEntity<T> implements Serializable {

    /**
     * 状态码
     */
    protected Integer status;
    /**
     * 提示信息
     */
    protected String msg;

    /**
     * 错误描述
     */
    protected String desc;
    /**
     * 返回数据
     */
    protected T data;
    
	 public ResponseEntity() {
        this.message = "操作成功";
        this.status = 200;
    }
   }

2、全局异常处理

定义一些处理异常的方法，可以添加项目中自定义的一些异常

@RestControllerAdvice
@Component
@Slf4j
public class CustomExceptionAdivsor {

    @ExceptionHandler(value = MethodArgumentNotValidException.class)
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    public ResponseEntity to400(MethodArgumentNotValidException e) {
        ResponseEntity responseEntity = new ResponseEntity()
                .setStatus(HttpStatus.BAD_REQUEST.value())
                .setDesc(e.getMessage());
        return responseEntity;
    }

    @ExceptionHandler(value = AuthorizationException.class)
    @ResponseStatus(HttpStatus.FORBIDDEN)
    public ResponseEntity to403(AuthorizationException e) {
        ResponseEntity responseEntity = new ResponseEntity()
                .setStatus(HttpStatus.FORBIDDEN.value())
                .setDesc(e.getMessage());
        return responseEntity;
    }

    @ExceptionHandler(RuntimeException.class)
    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
    public ResponseEntity to500(RuntimeException e) {
        ResponseEntity responseEntity = new ResponseEntity()
                .setStatus(HttpStatus.INTERNAL_SERVER_ERROR.value())
                .setDesc(e.getMessage());
        return responseEntity;
    }

    @ExceptionHandler(value = Throwable.class)
    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
    public ResponseEntity to500(Throwable throwable) {
        ResponseEntity responseEntity = new ResponseEntity()
                .setStatus(HttpStatus.INTERNAL_SERVER_ERROR.value())
                .setDesc(throwable.getMessage());
        return responseEntity;
    }

}

3、@RestControllerAdvice

@RestControllerAdvice 包含了 @ControllerAdvice 和 @ResponseBody

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@ControllerAdvice
@ResponseBody
public @interface RestControllerAdvice {

二、原理

在上一篇文章中分析过了

来源：https://blog.csdn.net/RenshenLi/article/details/122247740