/*

  * 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.web.filter.authc;

 import org.apache.shiro.web.filter.PathMatchingFilter;

 import javax.servlet.ServletRequest;

 import javax.servlet.ServletResponse;

 /**

  * Filter that allows access to a path immeidately without performing security checks of any kind.

  * <p/>

  * This filter is useful primarily in exclusionary policies, where you have defined a url pattern

  * to require a certain security level, but maybe only subset of urls in that pattern should allow any access.

  * <p/>

  * For example, if you had a user-only section of a website, you might want to require that access to

  * any url in that section must be from an authenticated user.

  * <p/>

  * Here is how that would look in the IniShiroFilter configuration:

  * <p/>

  * <code>[urls]<br/>

  * /user/** = authc</code>

  * <p/>

  * But if you wanted <code>/user/signup/**</code> to be available to anyone, you have to exclude that path since

  * it is a subset of the first.  This is where the AnonymousFilter ('anon') is useful:

  * <p/>

  * <code>[urls]<br/>

  * /user/signup/** = anon<br/>

  * /user/** = authc</code>>

  * <p/>

  * Since the url pattern definitions follow a 'first match wins' paradigm, the <code>anon</code> filter will

  * match the <code>/user/signup/**</code> paths and the <code>/user/**</code> path chain will not be evaluated.

  *

  * @since 0.9

  */

 public class AnonymousFilter extends PathMatchingFilter {

     /**

      * Always returns <code>true</code> allowing unchecked access to the underlying path or resource.

      *

      * @return <code>true</code> always, allowing unchecked access to the underlying path or resource.

      */

     @Override

     protected boolean onPreHandle(ServletRequest request, ServletResponse response, Object mappedValue) {

         // Always return true since we allow access to anyone

         return true;

     }

 }