1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 */ 19 package org.apache.shiro.web.tags; 20 21 import javax.servlet.jsp.JspException; 22 import javax.servlet.jsp.tagext.TagSupport; 23 24 import org.slf4j.Logger; 25 import org.slf4j.LoggerFactory; 26 27 28 /** 29 * JSP tag that renders the tag body if the current user <em>is not</em> known to the system, either because they 30 * haven't logged in yet, or because they have no 'RememberMe' identity. 31 * 32 * <p>The logically opposite tag of this one is the {@link UserTag}. Please read that class's JavaDoc as it explains 33 * more about the differences between Authenticated/Unauthenticated and User/Guest semantic differences. 34 * 35 * @since 0.9 36 */ 37 public class GuestTag extends SecureTag { 38 39 //TODO - complete JavaDoc 40 41 private static final Logger log = LoggerFactory.getLogger(GuestTag.class); 42 43 public int onDoStartTag() throws JspException { 44 if (getSubject() == null || getSubject().getPrincipal() == null) { 45 if (log.isTraceEnabled()) { 46 log.trace("Subject does not exist or does not have a known identity (aka 'principal'). " + 47 "Tag body will be evaluated."); 48 } 49 return TagSupport.EVAL_BODY_INCLUDE; 50 } else { 51 if (log.isTraceEnabled()) { 52 log.trace("Subject exists or has a known identity (aka 'principal'). " + 53 "Tag body will not be evaluated."); 54 } 55 return TagSupport.SKIP_BODY; 56 } 57 } 58 59 }