/*
* $Header: /home/cvs/jakarta-struts/src/share/org/apache/struts/taglib/LinkTag.java,v 1.12 2001/05/20 01:19:04 craigmcc Exp $
* $Revision: 1.12 $
* $Date: 2001/05/20 01:19:04 $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.struts.taglib;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.net.URLEncoder;
import java.util.Iterator;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.TagSupport;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionForwards;
import org.apache.struts.util.BeanUtils;
import org.apache.struts.util.MessageResources;
import org.apache.struts.util.PropertyUtils;
import org.apache.struts.util.ResponseUtils;
/**
* Generate a URL-encoded hyperlink to the specified URI.
*
* @author Craig R. McClanahan
* @version $Revision: 1.12 $ $Date: 2001/05/20 01:19:04 $
*/
public class LinkTag extends TagSupport {
// ----------------------------------------------------- Instance Variables
/**
* The logical forward name from which to retrieve the hyperlink URI.
*/
protected String forward = null;
/**
* The hyperlink URI.
*/
protected String href = null;
/**
* The message resources for this package.
*/
protected static MessageResources messages =
MessageResources.getMessageResources
("org.apache.struts.taglib.LocalStrings");
/**
* The JSP bean name for query parameters.
*/
protected String name = null;
/**
* The JSP bean property name for query parameters.
*/
protected String property = null;
/**
* The window target.
*/
protected String target = null;
// ------------------------------------------------------------- Properties
/**
* Return the logical forward name.
*/
public String getForward() {
return (this.forward);
}
/**
* Set the logical forward name.
*
* @param forward The new logical forward name
*/
public void setForward(String forward) {
this.forward = forward;
}
/**
* Return the hyperlink URI.
*/
public String getHref() {
return (this.href);
}
/**
* Set the hyperlink URI.
*
* @param href Set the hyperlink URI
*/
public void setHref(String href) {
this.href = href;
}
/**
* Return the bean name.
*/
public String getName() {
return (this.name);
}
/**
* Set the bean name.
*
* @param name The bean name
*/
public void setName(String name) {
this.name = name;
}
/**
* Return the property name.
*/
public String getProperty() {
return (this.property);
}
/**
* Set the property name.
*
* @param property The property name
*/
public void setProperty(String property) {
this.property = property;
}
/**
* Return the window target.
*/
public String getTarget() {
return (this.target);
}
/**
* Set the window target.
*
* @param target The new window target
*/
public void setTarget(String target) {
this.target = target;
}
// --------------------------------------------------------- Public Methods
/**
* Render the beginning of the hyperlink.
*
* @exception JspException if a JSP exception has occurred
*/
public int doStartTag() throws JspException {
// Validate our attributes
if ((forward == null) && (href == null))
throw new JspException
(messages.getMessage("linkTag.destination"));
else if ((forward != null) && (href != null))
throw new JspException
(messages.getMessage("linkTag.destination"));
// Generate the hyperlink start element
HttpServletResponse response =
(HttpServletResponse) pageContext.getResponse();
StringBuffer results = new StringBuffer("<a href=\"");
results.append(response.encodeURL(ResponseUtils.filter(hyperlink())));
results.append("\"");
if (target != null) {
results.append(" target=\"");
results.append(target);
results.append("\"");
}
results.append(">");
// Print this element to our output writer
JspWriter writer = pageContext.getOut();
try {
writer.print(results.toString());
} catch (IOException e) {
throw new JspException
(messages.getMessage("common.io", e.toString()));
}
// Evaluate the body of this tag
return (EVAL_BODY_INCLUDE);
}
/**
* Render the end of the hyperlink.
*
* @exception JspException if a JSP exception has occurred
*/
public int doEndTag() throws JspException {
// Print the ending element to our output writer
JspWriter writer = pageContext.getOut();
try {
writer.print("</a>");
} catch (IOException e) {
throw new JspException
(messages.getMessage("common.io", e.toString()));
}
return (EVAL_PAGE);
}
/**
* Release any acquired resources.
*/
public void release() {
super.release();
forward = null;
href = null;
name = null;
property = null;
target = null;
}
// ------------------------------------------------------ Protected Methods
/**
* Return the specified hyperlink, modified as necessary with optional
* request parameters.
*
* @exception JspException if an error occurs preparing the hyperlink
*/
protected String hyperlink() throws JspException {
String href = this.href;
// If "forward" was specified, compute the "href" to forward to
if (forward != null) {
ActionForwards forwards = (ActionForwards)
pageContext.getAttribute(Action.FORWARDS_KEY,
PageContext.APPLICATION_SCOPE);
if (forwards == null)
throw new JspException
(messages.getMessage("linkTag.forwards"));
ActionForward forward = forwards.findForward(this.forward);
if (forward == null)
throw new JspException
(messages.getMessage("linkTag.forward"));
HttpServletRequest request =
(HttpServletRequest) pageContext.getRequest();
href = request.getContextPath() + forward.getPath();
}
// Just return the "href" attribute if there is no bean to look up
if ((property != null) && (name == null))
throw new JspException
(messages.getMessage("getter.name"));
if (name == null)
return (href);
// Look up the map we will be using
Object bean = pageContext.findAttribute(name);
if (bean == null)
throw new JspException
(messages.getMessage("getter.bean", name));
Map map = null;
if (property == null) {
try {
map = (Map) bean;
} catch (ClassCastException e) {
throw new JspException
(messages.getMessage("linkTag.type"));
}
} else {
try {
map = (Map) PropertyUtils.getProperty(bean, property);
if (map == null)
throw new JspException
(messages.getMessage("getter.property", property));
} catch (IllegalAccessException e) {
throw new JspException
(messages.getMessage("getter.access", property, name));
} catch (InvocationTargetException e) {
Throwable t = e.getTargetException();
throw new JspException
(messages.getMessage("getter.result",
property, t.toString()));
} catch (ClassCastException e) {
throw new JspException
(messages.getMessage("linkTag.type"));
} catch (NoSuchMethodException e) {
throw new JspException
(messages.getMessage("getter.method", property, name));
}
}
// Append the required query parameters
StringBuffer sb = new StringBuffer(href);
boolean question = (href.indexOf("?") >= 0);
Iterator keys = map.keySet().iterator();
while (keys.hasNext()) {
String key = (String) keys.next();
Object value = map.get(key);
if (value instanceof String[]) {
String values[] = (String[]) value;
for (int i = 0; i < values.length; i++) {
if (question)
sb.append('&');
else {
sb.append('?');
question = true;
}
sb.append(key);
sb.append('=');
sb.append(URLEncoder.encode(values[i]));
}
} else {
if (question)
sb.append('&');
else {
sb.append('?');
question = true;
}
sb.append(key);
sb.append('=');
sb.append(URLEncoder.encode(value.toString()));
}
}
// Return the final result
return (sb.toString());
}
}