/*
* $Id: HeaderTag.java 471754 2006-11-06 14:55:09Z husted $
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.struts.taglib.bean;
import org.apache.struts.taglib.TagUtils;
import org.apache.struts.util.MessageResources;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;
import java.util.ArrayList;
import java.util.Enumeration;
/**
* Define a scripting variable based on the value(s) of the specified header
* received with this request.
*
* @version $Rev: 471754 $ $Date: 2004-10-16 12:38:42 -0400 (Sat, 16 Oct 2004)
* $
*/
public class HeaderTag extends TagSupport {
/**
* The message resources for this package.
*/
protected static MessageResources messages =
MessageResources.getMessageResources(
"org.apache.struts.taglib.bean.LocalStrings");
// ------------------------------------------------------------- Properties
/**
* The name of the scripting variable that will be exposed as a page scope
* attribute.
*/
protected String id = null;
/**
* Return an array of header values if <code>multiple</code> is non-null.
*/
protected String multiple = null;
/**
* The name of the header whose value is to be exposed.
*/
protected String name = null;
/**
* The default value to return if no header of the specified name is
* found.
*/
protected String value = null;
public String getId() {
return (this.id);
}
public void setId(String id) {
this.id = id;
}
public String getMultiple() {
return (this.multiple);
}
public void setMultiple(String multiple) {
this.multiple = multiple;
}
public String getName() {
return (this.name);
}
public void setName(String name) {
this.name = name;
}
public String getValue() {
return (this.value);
}
public void setValue(String value) {
this.value = value;
}
// --------------------------------------------------------- Public Methods
/**
* Retrieve the required property and expose it as a scripting variable.
*
* @throws JspException if a JSP exception has occurred
*/
public int doStartTag() throws JspException {
if (this.multiple == null) {
this.handleSingleHeader();
} else {
this.handleMultipleHeaders();
}
return SKIP_BODY;
}
/**
* Expose an array of header values.
*
* @throws JspException
* @since Struts 1.2
*/
protected void handleMultipleHeaders()
throws JspException {
ArrayList values = new ArrayList();
Enumeration items =
((HttpServletRequest) pageContext.getRequest()).getHeaders(name);
while (items.hasMoreElements()) {
values.add(items.nextElement());
}
if (values.isEmpty() && (this.value != null)) {
values.add(this.value);
}
String[] headers = new String[values.size()];
if (headers.length == 0) {
JspException e =
new JspException(messages.getMessage("header.get", name));
TagUtils.getInstance().saveException(pageContext, e);
throw e;
}
pageContext.setAttribute(id, values.toArray(headers));
}
/**
* Expose a single header value.
*
* @throws JspException
* @since Struts 1.2
*/
protected void handleSingleHeader()
throws JspException {
String value =
((HttpServletRequest) pageContext.getRequest()).getHeader(name);
if ((value == null) && (this.value != null)) {
value = this.value;
}
if (value == null) {
JspException e =
new JspException(messages.getMessage("header.get", name));
TagUtils.getInstance().saveException(pageContext, e);
throw e;
}
pageContext.setAttribute(id, value);
}
/**
* Release all allocated resources.
*/
public void release() {
super.release();
id = null;
multiple = null;
name = null;
value = null;
}
}