org.apache.taglibs.standard.tag.common.core.UrlSupport Maven / Gradle / Ivy
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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.core;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.jsp.JspException;
import jakarta.servlet.jsp.JspTagException;
import jakarta.servlet.jsp.PageContext;
import jakarta.servlet.jsp.tagext.BodyTagSupport;
import org.apache.taglibs.standard.resources.Resources;
/**
* Support for tag handlers for <url>, the URL creation
* and rewriting tag in JSTL 1.0.
*
* @author Shawn Bayern
*/
public abstract class UrlSupport extends BodyTagSupport
implements ParamParent {
//*********************************************************************
// Protected state
protected String value; // 'value' attribute
protected String context; // 'context' attribute
//*********************************************************************
// Private state
private String var; // 'var' attribute
private int scope; // processed 'scope' attr
private ParamSupport.ParamManager params; // added parameters
//*********************************************************************
// Constructor and initialization
public UrlSupport() {
super();
init();
}
private void init() {
value = var = null;
params = null;
context = null;
scope = PageContext.PAGE_SCOPE;
}
//*********************************************************************
// Tag attributes known at translation time
public void setVar(String var) {
this.var = var;
}
public void setScope(String scope) {
this.scope = Util.getScope(scope);
}
//*********************************************************************
// Collaboration with subtags
// inherit Javadoc
public void addParameter(String name, String value) {
params.addParameter(name, value);
}
//*********************************************************************
// Tag logic
// resets any parameters that might be sent
public int doStartTag() throws JspException {
params = new ParamSupport.ParamManager();
return EVAL_BODY_BUFFERED;
}
// gets the right value, encodes it, and prints or stores it
public int doEndTag() throws JspException {
String result; // the eventual result
// add (already encoded) parameters
String baseUrl = resolveUrl(value, context, pageContext);
result = params.aggregateParams(baseUrl);
// if the URL is relative, rewrite it
if (!ImportSupport.isAbsoluteUrl(result)) {
HttpServletResponse response =
((HttpServletResponse) pageContext.getResponse());
result = response.encodeURL(result);
}
// store or print the output
if (var != null)
pageContext.setAttribute(var, result, scope);
else {
try {
pageContext.getOut().print(result);
} catch (java.io.IOException ex) {
throw new JspTagException(ex.toString(), ex);
}
}
return EVAL_PAGE;
}
// Releases any resources we may have (or inherit)
public void release() {
init();
}
//*********************************************************************
// Utility methods
public static String resolveUrl(
String url, String context, PageContext pageContext)
throws JspException {
// don't touch absolute URLs
if (ImportSupport.isAbsoluteUrl(url))
return url;
// normalize relative URLs against a context root
HttpServletRequest request =
(HttpServletRequest) pageContext.getRequest();
if (context == null) {
if (url.startsWith("/"))
return (request.getContextPath() + url);
else
return url;
} else {
if (!context.startsWith("/") || !url.startsWith("/")) {
throw new JspTagException(
Resources.getMessage("IMPORT_BAD_RELATIVE"));
}
if (context.equals("/")) {
// Don't produce string starting with '//', many
// browsers interpret this as host name, not as
// path on same host.
return url;
} else {
return (context + url);
}
}
}
}