/*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you under the Apache License, Version 2.0 (the

  * "License"); you may not use this file except in compliance

  * with the License.  You may obtain a copy of the License at

  *

  *     http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing,

  * software distributed under the License is distributed on an

  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

  * KIND, either express or implied.  See the License for the

  * specific language governing permissions and limitations

  * under the License.

  */

 package org.apache.shiro.authz.aop;

 import java.util.ArrayList;

 import java.util.Collection;

 import org.apache.shiro.aop.MethodInvocation;

 import org.apache.shiro.authz.AuthorizationException;

 /**

  * An <tt>AnnotationsAuthorizingMethodInterceptor</tt> is a MethodInterceptor that asserts a given method is authorized

  * to execute based on one or more configured <tt>AuthorizingAnnotationMethodInterceptor</tt>s.

  *

  * <p>This allows multiple annotations on a method to be processed before the method

  * executes, and if any of the <tt>AuthorizingAnnotationMethodInterceptor</tt>s indicate that the method should not be

  * executed, an <tt>AuthorizationException</tt> will be thrown, otherwise the method will be invoked as expected.

  *

  * <p>It is essentially a convenience mechanism to allow multiple annotations to be processed in a single method

  * interceptor.

  *

  * @since 0.2

  */

 public abstract class AnnotationsAuthorizingMethodInterceptor extends AuthorizingMethodInterceptor {

     /**

      * The method interceptors to execute for the annotated method.

      */

     protected Collection<AuthorizingAnnotationMethodInterceptor> methodInterceptors;

     /**

      * Default no-argument constructor that defaults the 

      * {@link #methodInterceptors methodInterceptors} attribute to contain two interceptors by default - the

      * {@link RoleAnnotationMethodInterceptor RoleAnnotationMethodInterceptor} and the

      * {@link PermissionAnnotationMethodInterceptor PermissionAnnotationMethodInterceptor} to

      * support role and permission annotations.

      */

     public AnnotationsAuthorizingMethodInterceptor() {

         methodInterceptors = new ArrayList<AuthorizingAnnotationMethodInterceptor>(5);

         methodInterceptors.add(new RoleAnnotationMethodInterceptor());

         methodInterceptors.add(new PermissionAnnotationMethodInterceptor());

         methodInterceptors.add(new AuthenticatedAnnotationMethodInterceptor());

         methodInterceptors.add(new UserAnnotationMethodInterceptor());

         methodInterceptors.add(new GuestAnnotationMethodInterceptor());

     }

     /**

      * Returns the method interceptors to execute for the annotated method.

      * <p/>

      * Unless overridden by the {@link #setMethodInterceptors(java.util.Collection)} method, the default collection

      * contains a

      * {@link RoleAnnotationMethodInterceptor RoleAnnotationMethodInterceptor} and a

      * {@link PermissionAnnotationMethodInterceptor PermissionAnnotationMethodInterceptor} to

      * support role and permission annotations automatically.

      * @return the method interceptors to execute for the annotated method.

      */

     public Collection<AuthorizingAnnotationMethodInterceptor> getMethodInterceptors() {

         return methodInterceptors;

     }

     /**

      * Sets the method interceptors to execute for the annotated method.

      * @param methodInterceptors the method interceptors to execute for the annotated method.

      * @see #getMethodInterceptors()

      */

     public void setMethodInterceptors(Collection<AuthorizingAnnotationMethodInterceptor> methodInterceptors) {

         this.methodInterceptors = methodInterceptors;

     }

     /**

      * Iterates over the internal {@link #getMethodInterceptors() methodInterceptors} collection, and for each one,

      * ensures that if the interceptor

      * {@link AuthorizingAnnotationMethodInterceptor#supports(org.apache.shiro.aop.MethodInvocation) supports}

      * the invocation, that the interceptor

      * {@link AuthorizingAnnotationMethodInterceptor#assertAuthorized(org.apache.shiro.aop.MethodInvocation) asserts}

      * that the invocation is authorized to proceed.

      */

     protected void assertAuthorized(MethodInvocation methodInvocation) throws AuthorizationException {

         //default implementation just ensures no deny votes are cast:

         Collection<AuthorizingAnnotationMethodInterceptor> aamis = getMethodInterceptors();

         if (aamis != null && !aamis.isEmpty()) {

             for (AuthorizingAnnotationMethodInterceptor aami : aamis) {

                 if (aami.supports(methodInvocation)) {

                     aami.assertAuthorized(methodInvocation);

                 }

             }

         }

     }

 }