/*

  * 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.permission;

 import org.apache.shiro.authz.Permission;

 /**

  * A {@code PermisisonResolver} resolves a String value and converts it into a

  * {@link org.apache.shiro.authz.Permission Permission} instance.

  * <p/>

  * The default {@link WildcardPermissionResolver} should be

  * suitable for most purposes, which constructs {@link WildcardPermission} objects.

  * However, any resolver may be configured if an application wishes to use different

  * {@link org.apache.shiro.authz.Permission} implementations.

  * <p/>

  * A {@code PermissionResolver} is used by many Shiro components such as annotations, property file

  * configuration, URL configuration, etc.  It is useful whenever a String representation of a permission is specified

  * and that String needs to be converted to a Permission instance before executing a security check.

  * <p/>

  * Shiro chooses to support {@link WildcardPermission Wildcardpermission}s by default in almost all components and

  * we do that in the form of the {@link WildcardPermissionResolver WildcardPermissionResolver}.   One of the nice

  * things about {@code WildcardPermission}s being supported by default is that it makes it very easy to

  * store complex permissions in the database - and also makes it very easy to represent permissions in JSP files,

  * annotations, etc., where a simple string representation is useful.

  * <p/>

  * Although this happens to be the Shiro default, you are of course free to provide custom

  * String-to-Permission conversion by providing Shiro components any instance of this interface.

  *

  * @see org.apache.shiro.authz.ModularRealmAuthorizer#setPermissionResolver(PermissionResolver) ModularRealmAuthorizer.setPermissionResolver

  * @see org.apache.shiro.realm.AuthorizingRealm#setPermissionResolver(PermissionResolver) AuthorizingRealm.setPermissionResolver

  * @see PermissionResolverAware PermissionResolverAware

  * @since 0.9

  */

 public interface PermissionResolver {

     /**

      * Resolves a Permission based on the given String representation.

      *

      * @param permissionString the String representation of a permission.

      * @return A Permission object that can be used internally to determine a subject's permissions.

      * @throws InvalidPermissionStringException

      *          if the permission string is not valid for this resolver.

      */

     Permission resolvePermission(String permissionString);

 }