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Jakarta Standard Tag Library Implementation
/*
* Copyright (c) 1997-2020 Oracle and/or its affiliates. All rights reserved.
* Copyright 2004 The Apache Software Foundation
*
* Licensed 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.taglibs.standard.tag.common.fmt;
import jakarta.servlet.jsp.JspException;
import jakarta.servlet.jsp.JspTagException;
import jakarta.servlet.jsp.tagext.BodyTagSupport;
import jakarta.servlet.jsp.tagext.Tag;
import org.apache.taglibs.standard.resources.Resources;
/**
* Support for tag handlers for <param>, the message argument
* subtag in JSTL 1.0 which supplies an argument for parametric replacement
* to its parent <message> tag.
*
* @see MessageSupport
* @author Jan Luehe
*/
public abstract class ParamSupport extends BodyTagSupport {
//*********************************************************************
// Protected state
protected Object value; // 'value' attribute
protected boolean valueSpecified; // status
//*********************************************************************
// Constructor and initialization
public ParamSupport() {
super();
init();
}
private void init() {
value = null;
valueSpecified = false;
}
//*********************************************************************
// Tag logic
// Supply our value to our parent tag
public int doEndTag() throws JspException {
Tag t = findAncestorWithClass(this, MessageSupport.class);
if (t == null) {
throw new JspTagException(Resources.getMessage(
"PARAM_OUTSIDE_MESSAGE"));
}
MessageSupport parent = (MessageSupport) t;
/*
* Get argument from 'value' attribute or body, as appropriate, and
* add it to enclosing tag, even if it is null or equal
* to "".
*/
Object input = null;
// determine the input by...
if (valueSpecified) {
// ... reading 'value' attribute
input = value;
} else {
// ... retrieving and trimming our body (TLV has ensured that it's
// non-empty)
input = bodyContent.getString().trim();
}
parent.addParam(input);
return EVAL_PAGE;
}
// Releases any resources we may have (or inherit)
public void release() {
init();
}
}