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.authc.pam; 020 021 import org.apache.shiro.authc.AuthenticationException; 022 import org.apache.shiro.authc.AuthenticationInfo; 023 import org.apache.shiro.authc.AuthenticationToken; 024 import org.apache.shiro.realm.Realm; 025 import org.apache.shiro.util.CollectionUtils; 026 027 import java.util.Collection; 028 029 /** 030 * {@link AuthenticationStrategy} implementation that only accepts the account data from 031 * the first successfully consulted Realm and ignores all subsequent realms. This is slightly 032 * different behavior than {@link AtLeastOneSuccessfulStrategy}, so please review both to see 033 * which one meets your needs better. 034 * 035 * @see AtLeastOneSuccessfulStrategy AtLeastOneSuccessfulAuthenticationStrategy 036 * @since 0.9 037 */ 038 public class FirstSuccessfulStrategy extends AbstractAuthenticationStrategy { 039 040 /** 041 * Returns {@code null} immediately, relying on this class's {@link #merge merge} implementation to return 042 * only the first {@code info} object it encounters, ignoring all subsequent ones. 043 */ 044 public AuthenticationInfo beforeAllAttempts(Collection<? extends Realm> realms, AuthenticationToken token) throws AuthenticationException { 045 return null; 046 } 047 048 /** 049 * Returns the specified {@code aggregate} instance if is non null and valid (that is, has principals and they are 050 * not empty) immediately, or, if it is null or not valid, the {@code info} argument is returned instead. 051 * <p/> 052 * This logic ensures that the first valid info encountered is the one retained and all subsequent ones are ignored, 053 * since this strategy mandates that only the info from the first successfully authenticated realm be used. 054 */ 055 protected AuthenticationInfo merge(AuthenticationInfo info, AuthenticationInfo aggregate) { 056 if (aggregate != null && !CollectionUtils.isEmpty(aggregate.getPrincipals())) { 057 return aggregate; 058 } 059 return info != null ? info : aggregate; 060 } 061 }