001/* 002 * Copyright 2002-2015 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.web.servlet.tags; 018 019import javax.servlet.jsp.JspException; 020import javax.servlet.jsp.tagext.BodyTagSupport; 021 022/** 023 * JSP tag for collecting name-value parameters and passing them to a 024 * {@link ParamAware} ancestor in the tag hierarchy. 025 * 026 * <p>This tag must be nested under a param aware tag. 027 * 028 * @author Scott Andrews 029 * @author Nicholas Williams 030 * @since 3.0 031 * @see Param 032 * @see UrlTag 033 */ 034@SuppressWarnings("serial") 035public class ParamTag extends BodyTagSupport { 036 037 private String name; 038 039 private String value; 040 041 private boolean valueSet; 042 043 044 /** 045 * Set the name of the parameter (required). 046 */ 047 public void setName(String name) { 048 this.name = name; 049 } 050 051 /** 052 * Set the value of the parameter (optional). 053 */ 054 public void setValue(String value) { 055 this.value = value; 056 this.valueSet = true; 057 } 058 059 060 @Override 061 public int doEndTag() throws JspException { 062 Param param = new Param(); 063 param.setName(this.name); 064 if (this.valueSet) { 065 param.setValue(this.value); 066 } 067 else if (getBodyContent() != null) { 068 // Get the value from the tag body 069 param.setValue(getBodyContent().getString().trim()); 070 } 071 072 // Find a param aware ancestor 073 ParamAware paramAwareTag = (ParamAware) findAncestorWithClass(this, ParamAware.class); 074 if (paramAwareTag == null) { 075 throw new JspException("The param tag must be a descendant of a tag that supports parameters"); 076 } 077 078 paramAwareTag.addParam(param); 079 080 return EVAL_PAGE; 081 } 082 083 @Override 084 public void release() { 085 super.release(); 086 this.name = null; 087 this.value = null; 088 this.valueSet = false; 089 } 090 091}