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 */ 019 020 // 021 // This source code implements specifications defined by the Java 022 // Community Process. In order to remain compliant with the specification 023 // DO NOT add / change / or delete method signatures! 024 // 025 026 package javax.servlet.jsp.tagext; 027 028 import javax.servlet.jsp.JspException; 029 import javax.servlet.jsp.JspWriter; 030 031 /** 032 * A base class for defining tag handlers implementing BodyTag. 033 * 034 * <p> 035 * The BodyTagSupport class implements the BodyTag interface and adds 036 * additional convenience methods including getter methods for the 037 * bodyContent property and methods to get at the previous out JspWriter. 038 * 039 * <p> 040 * Many tag handlers will extend BodyTagSupport and only redefine a 041 * few methods. 042 */ 043 044 public class BodyTagSupport extends TagSupport implements BodyTag { 045 046 /** 047 * Default constructor, all subclasses are required to only define 048 * a public constructor with the same signature, and to call the 049 * superclass constructor. 050 * 051 * This constructor is called by the code generated by the JSP 052 * translator. 053 */ 054 055 public BodyTagSupport() { 056 super(); 057 } 058 059 /** 060 * Default processing of the start tag returning EVAL_BODY_BUFFERED. 061 * 062 * @return EVAL_BODY_BUFFERED 063 * @throws JspException if an error occurred while processing this tag 064 * @see BodyTag#doStartTag 065 */ 066 067 public int doStartTag() throws JspException { 068 return EVAL_BODY_BUFFERED; 069 } 070 071 072 /** 073 * Default processing of the end tag returning EVAL_PAGE. 074 * 075 * @return EVAL_PAGE 076 * @throws JspException if an error occurred while processing this tag 077 * @see Tag#doEndTag 078 */ 079 080 public int doEndTag() throws JspException { 081 return super.doEndTag(); 082 } 083 084 085 // Actions related to body evaluation 086 087 /** 088 * Prepare for evaluation of the body: stash the bodyContent away. 089 * 090 * @param b the BodyContent 091 * @see #doAfterBody 092 * @see #doInitBody() 093 * @see BodyTag#setBodyContent 094 */ 095 096 public void setBodyContent(BodyContent b) { 097 this.bodyContent = b; 098 } 099 100 101 /** 102 * Prepare for evaluation of the body just before the first body evaluation: 103 * no action. 104 * 105 * @throws JspException if an error occurred while processing this tag 106 * @see #setBodyContent 107 * @see #doAfterBody 108 * @see BodyTag#doInitBody 109 */ 110 111 public void doInitBody() throws JspException { 112 } 113 114 115 /** 116 * After the body evaluation: do not reevaluate and continue with the page. 117 * By default nothing is done with the bodyContent data (if any). 118 * 119 * @return SKIP_BODY 120 * @throws JspException if an error occurred while processing this tag 121 * @see #doInitBody 122 * @see BodyTag#doAfterBody 123 */ 124 125 public int doAfterBody() throws JspException { 126 return SKIP_BODY; 127 } 128 129 130 /** 131 * Release state. 132 * 133 * @see Tag#release 134 */ 135 136 public void release() { 137 bodyContent = null; 138 139 super.release(); 140 } 141 142 /** 143 * Get current bodyContent. 144 * 145 * @return the body content. 146 */ 147 148 public BodyContent getBodyContent() { 149 return bodyContent; 150 } 151 152 153 /** 154 * Get surrounding out JspWriter. 155 * 156 * @return the enclosing JspWriter, from the bodyContent. 157 */ 158 159 public JspWriter getPreviousOut() { 160 return bodyContent.getEnclosingWriter(); 161 } 162 163 // protected fields 164 165 /** 166 * The current BodyContent for this BodyTag. 167 */ 168 protected BodyContent bodyContent; 169 }