/*
* $Id: MatchTag.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.logic;
import org.apache.struts.taglib.TagUtils;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
/**
* Evalute the nested body content of this tag if the specified value is a
* substring of the specified variable.
*
* @version $Rev: 471754 $ $Date: 2004-10-16 12:38:42 -0400 (Sat, 16 Oct 2004)
* $
*/
public class MatchTag extends ConditionalTagBase {
// ------------------------------------------------------------- Properties
/**
* The location where the match must exist (<code>start</code> or
* <code>end</code>), or <code>null</code> for anywhere.
*/
protected String location = null;
/**
* The value to which the variable specified by other attributes of this
* tag will be matched.
*/
protected String value = null;
public String getLocation() {
return (this.location);
}
public void setLocation(String location) {
this.location = location;
}
public String getValue() {
return (this.value);
}
public void setValue(String value) {
this.value = value;
}
// --------------------------------------------------------- Public Methods
/**
* Release all allocated resources.
*/
public void release() {
super.release();
location = null;
value = null;
}
// ------------------------------------------------------ Protected Methods
/**
* Evaluate the condition that is being tested by this particular tag, and
* return <code>true</code> if the nested body content of this tag should
* be evaluated, or <code>false</code> if it should be skipped. This
* method must be implemented by concrete subclasses.
*
* @throws JspException if a JSP exception occurs
*/
protected boolean condition()
throws JspException {
return (condition(true));
}
/**
* Evaluate the condition that is being tested by this particular tag, and
* return <code>true</code> if the nested body content of this tag should
* be evaluated, or <code>false</code> if it should be skipped. This
* method must be implemented by concrete subclasses.
*
* @param desired Desired value for a true result
* @throws JspException if a JSP exception occurs
*/
protected boolean condition(boolean desired)
throws JspException {
// Acquire the specified variable
String variable = null;
if (cookie != null) {
Cookie[] cookies =
((HttpServletRequest) pageContext.getRequest()).getCookies();
if (cookies == null) {
cookies = new Cookie[0];
}
for (int i = 0; i < cookies.length; i++) {
if (cookie.equals(cookies[i].getName())) {
variable = cookies[i].getValue();
break;
}
}
} else if (header != null) {
variable =
((HttpServletRequest) pageContext.getRequest()).getHeader(header);
} else if (name != null) {
Object value =
TagUtils.getInstance().lookup(pageContext, name, property, scope);
if (value != null) {
variable = value.toString();
}
} else if (parameter != null) {
variable = pageContext.getRequest().getParameter(parameter);
} else {
JspException e =
new JspException(messages.getMessage("logic.selector"));
TagUtils.getInstance().saveException(pageContext, e);
throw e;
}
if (variable == null) {
JspException e =
new JspException(messages.getMessage("logic.variable", value));
TagUtils.getInstance().saveException(pageContext, e);
throw e;
}
// Perform the comparison requested by the location attribute
boolean matched = false;
if (location == null) {
matched = (variable.indexOf(value) >= 0);
} else if (location.equals("start")) {
matched = variable.startsWith(value);
} else if (location.equals("end")) {
matched = variable.endsWith(value);
} else {
JspException e =
new JspException(messages.getMessage("logic.location", location));
TagUtils.getInstance().saveException(pageContext, e);
throw e;
}
// Return the final result
return (matched == desired);
}
}