通过注解实现调用指定的拦截器

import java.lang.annotation.ElementType;import java.lang.annotation.Target;import java.text.MessageFormat;import javax.annotation.PostConstruct;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.apache.commons.lang3.ArrayUtils;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.web.method.HandlerMethod;import org.springframework.web.servlet.AsyncHandlerInterceptor;import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;/** * 通过注解实现调用指定的拦截器 *  * @author Saleson Lee. * @date 2016年3月19日 * @time 下午6:58:10 */public class AnnotationHandlerInterceptor extends HandlerInterceptorAdapter {private static final Logger LOG = LoggerFactory.getLogger(AnnotationHandlerInterceptor.class);/** * 需要过滤的注解类型 */@SuppressWarnings("rawtypes")private Class annotationClass;/** * 过滤器 */private AsyncHandlerInterceptor[] handlerInterceptors;/** * 检测类或方法的注解 */private AnnotationTarget annotationTarget;@SuppressWarnings("unchecked")@PostConstructpublic void init() throws Exception {if (this.annotationClass == null) {throw new Exception("属性annotationClass为空");} else if (handlerInterceptors == null) {throw new Exception("属性handlerInterceptors为空");}if (annotationTarget == null) {Target target = (Target) annotationClass.getAnnotation(Target.class);if (target == null) {throw new Exception(MessageFormat.format("注解{0}没有定义{1}注解",annotationClass, target));}ElementType[] eTypes = target.value();if (ArrayUtils.contains(eTypes, ElementType.METHOD)&& ArrayUtils.contains(eTypes, ElementType.TYPE)) {annotationTarget = AnnotationTarget.TYPE_AND_METHOD;} else if (ArrayUtils.contains(eTypes, ElementType.METHOD)) {annotationTarget = AnnotationTarget.METHOD;} else if (ArrayUtils.contains(eTypes, ElementType.TYPE)) {annotationTarget = AnnotationTarget.TYPE;} else {throw new Exception(MessageFormat.format("注解{0}中{1}注解没有定义{2}或{3}", annotationClass, target,ElementType.TYPE, AnnotationTarget.METHOD));}}printDebugInitLog();}@SuppressWarnings("unchecked")@Overridepublic boolean preHandle(HttpServletRequest request,HttpServletResponse response, Object handler) throws Exception {HandlerMethod method = (HandlerMethod) handler;boolean invokable = false;switch (annotationTarget) {case METHOD:invokable = method.getMethod().getAnnotation(annotationClass) != null;break;case TYPE:invokable = method.getBeanType().getAnnotation(annotationClass) != null;break;case TYPE_AND_METHOD:invokable = method.getMethod().getAnnotation(annotationClass) != null|| method.getBeanType().getAnnotation(annotationClass) != null;break;}if (invokable) {return invokeHandlerInterceptorsPreHandle(request, response,handler);}return true;}/** * 调用过滤器 *  * @param request * @param response * @param handler * @return * @throws Exception */private boolean invokeHandlerInterceptorsPreHandle(HttpServletRequest request, HttpServletResponse response,Object handler) throws Exception {for (AsyncHandlerInterceptor handlerInterceptor : handlerInterceptors) {if (!handlerInterceptor.preHandle(request, response,handler)) {return false;}}return true;}/** * @param handlerInterceptors *            the handlerInterceptors to set */public void setHandlerInterceptors(AsyncHandlerInterceptor[] handlerInterceptors) {this.handlerInterceptors = handlerInterceptors;}/** * @param annotationClass *            the annotationClass to set */public void setAnnotationClass(String annotationClass) {try {this.annotationClass = Class.forName(annotationClass);} catch (ClassNotFoundException e) {LOG.error(MessageFormat.format("找不到类 ==> {0}", annotationClass), e);}}/** * @param annotationTarget *            the annotationTarget to set */public void setAnnotationTarget(AnnotationTarget annotationTarget) {this.annotationTarget = annotationTarget;}/** * 打印Debug日志 */private void printDebugInitLog() {switch (annotationTarget) {case TYPE_AND_METHOD:LOG.debug("拦截标有{}注解的Controller类和方法, 调用过滤器{}", annotationClass,handlerInterceptors);break;case TYPE:LOG.debug("拦截标有{}注解的Controller类, 调用过滤器{}", annotationClass,handlerInterceptors);break;case METHOD:LOG.debug("拦截标有{}注解的Controller类方法, 调用过滤器{}", annotationClass,handlerInterceptors);}}enum AnnotationTarget {TYPE_AND_METHOD, TYPE, METHOD}}