1.注解引入

1) @ControllerAdvice - 控制器增强

@Target({ElementType.TYPE})@Retention(RetentionPolicy.RUNTIME)@Documented@Componentpublic @interface ControllerAdvice {    @AliasFor("basePackages")    String[] value() default {};    @AliasFor("value")    String[] basePackages() default {};    Class
     [] basePackageClasses() default {};    Class
     [] assignableTypes() default {};    Class
     [] annotations() default {};}

1. @ControllerAdvice作为一个@Component,用以定义 @ExceptionHandler/@InitBinder/@ModelAttribute 修饰的方法 , 适用于所有使用 @RequestMapping的方法.
2. Spring4之前,@ControllerAdvice 在同一调度的Servlet中协助所有控制器.Spring4之后,@ControllerAdvice支持配置控制器的子集,且默认的行为仍可用
3. Spring4之后,@ControllerAdvice通过annotations()/basePackageClasses()/basePackages()方法定制用于选择控制器子集.

2) @ExceptionHandler - 异常处理器

@Target({ElementType.METHOD})@Retention(RetentionPolicy.RUNTIME)@Documentedpublic @interface ExceptionHandler {    Class
     [] value() default {};}

单独用@ExceptionHandler,限定当前Controller处理异常.配合@ControllerAdvice则摆脱此限制.

2.使用实例

@ControllerAdvicepublic class MultipartExceptionControllerAdvice {    private static final Logger log = LoggerFactory.getLogger(MultipartExceptionControllerAdvice.class);    /**     * 捕获文件上传异常     * @param ex     * @return     */    @ResponseBody    @ExceptionHandler(value = MultipartException.class)    public FrontResult fileErrorHandler(MultipartException ex) {        FrontResult result = new FrontResult();        result.setHasLive(0);        result.setCode(500);        result.setMsg("FAIL.");        log.error("file upload error : " , ex);        return result;    }}

3.处理Exception在捕获@ResponseStatus修饰的自定义异常时操作

import org.springframework.core.annotation.AnnotationUtils;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;import javax.servlet.http.HttpServletRequest;@ControllerAdvicepublic class ExceptionAdvice {    @ExceptionHandler(Exception.class)    @ResponseBody    public String handlerException(HttpServletRequest request , Exception e) throws Exception {                e.printStackTrace();        if (AnnotationUtils.findAnnotation(e.getClass(), ResponseStatus.class) != null) {            throw e;        }                return e.getMessage();    }}

 ::::  如果碰到了某个自定义异常加上了@ResponseStatus，就继续抛出，这样就不会让自定义异常失去加上@ResponseStatus的初衷。