/*

  * 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.aop;

 import java.lang.annotation.Annotation;

 import org.apache.shiro.SecurityUtils;

 import org.apache.shiro.subject.Subject;

 /**

  * Base support class for implementations that reads and processes JSR-175 annotations.

  *

  * @since 0.9.0

  */

 public abstract class AnnotationHandler {

     /**

      * The type of annotation this handler will process.

      */

     protected Class<? extends Annotation> annotationClass;

     /**

      * Constructs an <code>AnnotationHandler</code> who processes annotations of the

      * specified type.  Immediately calls {@link #setAnnotationClass(Class)}.

      *

      * @param annotationClass the type of annotation this handler will process.

      */

     public AnnotationHandler(Class<? extends Annotation> annotationClass) {

         setAnnotationClass(annotationClass);

     }

     /**

      * Returns the {@link org.apache.shiro.subject.Subject Subject} associated with the currently-executing code.

      * <p/>

      * This default implementation merely calls <code>{@link org.apache.shiro.SecurityUtils#getSubject SecurityUtils.getSubject()}</code>.

      *

      * @return the {@link org.apache.shiro.subject.Subject Subject} associated with the currently-executing code.

      */

     protected Subject getSubject() {

         return SecurityUtils.getSubject();

     }

     /**

      * Sets the type of annotation this handler will inspect and process.

      *

      * @param annotationClass the type of annotation this handler will process.

      * @throws IllegalArgumentException if the argument is <code>null</code>.

      */

     protected void setAnnotationClass(Class<? extends Annotation> annotationClass)

             throws IllegalArgumentException {

         if (annotationClass == null) {

             String msg = "annotationClass argument cannot be null";

             throw new IllegalArgumentException(msg);

         }

         this.annotationClass = annotationClass;

     }

     /**

      * Returns the type of annotation this handler inspects and processes.

      *

      * @return the type of annotation this handler inspects and processes.

      */

     public Class<? extends Annotation> getAnnotationClass() {

         return this.annotationClass;

     }

 }