001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing,
013     * software distributed under the License is distributed on an
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     * KIND, either express or implied.  See the License for the
016     * specific language governing permissions and limitations
017     * under the License.
018     */
019    package org.apache.shiro.authz.aop;
020    
021    import org.apache.shiro.authz.AuthorizationException;
022    import org.apache.shiro.authz.annotation.Logical;
023    import org.apache.shiro.authz.annotation.RequiresRoles;
024    
025    import java.lang.annotation.Annotation;
026    import java.util.Arrays;
027    
028    /**
029     * Checks to see if a @{@link org.apache.shiro.authz.annotation.RequiresRoles RequiresRoles} annotation is declared, and if so, performs
030     * a role check to see if the calling <code>Subject</code> is allowed to proceed.
031     *
032     * @since 0.9.0
033     */
034    public class RoleAnnotationHandler extends AuthorizingAnnotationHandler {
035    
036        /**
037         * Default no-argument constructor that ensures this handler looks for
038         * {@link org.apache.shiro.authz.annotation.RequiresRoles RequiresRoles} annotations.
039         */
040        public RoleAnnotationHandler() {
041            super(RequiresRoles.class);
042        }
043    
044        /**
045         * Ensures that the calling <code>Subject</code> has the Annotation's specified roles, and if not, throws an
046         * <code>AuthorizingException</code> indicating that access is denied.
047         *
048         * @param a the RequiresRoles annotation to use to check for one or more roles
049         * @throws org.apache.shiro.authz.AuthorizationException
050         *          if the calling <code>Subject</code> does not have the role(s) necessary to
051         *          proceed.
052         */
053        public void assertAuthorized(Annotation a) throws AuthorizationException {
054            if (!(a instanceof RequiresRoles)) return;
055    
056            RequiresRoles rrAnnotation = (RequiresRoles) a;
057            String[] roles = rrAnnotation.value();
058    
059            if (roles.length == 1) {
060                getSubject().checkRole(roles[0]);
061                return;
062            }
063            if (Logical.AND.equals(rrAnnotation.logical())) {
064                getSubject().checkRoles(Arrays.asList(roles));
065                return;
066            }
067            if (Logical.OR.equals(rrAnnotation.logical())) {
068                // Avoid processing exceptions unnecessarily - "delay" throwing the exception by calling hasRole first
069                boolean hasAtLeastOneRole = false;
070                for (String role : roles) if (getSubject().hasRole(role)) hasAtLeastOneRole = true;
071                // Cause the exception if none of the role match, note that the exception message will be a bit misleading
072                if (!hasAtLeastOneRole) getSubject().checkRole(roles[0]);
073            }
074        }
075    
076    }