/* * $Id: BaseTag.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.html; import org.apache.struts.Globals; import org.apache.struts.taglib.TagUtils; import org.apache.struts.util.MessageResources; import org.apache.struts.util.RequestUtils; import javax.servlet.http.HttpServletRequest; import javax.servlet.jsp.JspException; import javax.servlet.jsp.JspWriter; import javax.servlet.jsp.PageContext; import javax.servlet.jsp.tagext.TagSupport; import java.io.IOException; import java.util.StringTokenizer; /** * Renders an HTML <base> element with an href attribute pointing to the * absolute location of the enclosing JSP page. This tag is only valid when * nested inside a head tag body. The presence of this tag allows the browser * to resolve relative URL's to images, CSS stylesheets and other resources * in a manner independent of the URL used to call the ActionServlet. * * @version $Rev: 471754 $ $Date: 2005-09-20 02:29:01 -0400 (Tue, 20 Sep 2005) * $ */ public class BaseTag extends TagSupport { /** * The message resources for this package. */ protected static MessageResources messages = MessageResources.getMessageResources(Constants.Package + ".LocalStrings"); protected final String REF_SITE = "site"; protected final String REF_PAGE = "page"; /** * The server name to use instead of request.getServerName(). */ protected String server = null; /** * The target window for this base reference. */ protected String target = null; /** * The reference to which the base will created. */ protected String ref = REF_PAGE; /** * Gets the reference to which the base will be created */ public String getRef() { return (this.ref); } /** * Sets the reference to which the base will be created. * * @param ref Either "page" to render the base as the jsp path located, or * "site" as the application's context */ public void setRef(String ref) { if (ref == null) { throw new IllegalArgumentException("Ref attribute cannot be null"); } ref = ref.toLowerCase(); if (ref.equals(REF_PAGE) || ref.equals(REF_SITE)) { this.ref = ref; } else { throw new IllegalArgumentException("Ref attribute must either be " + "'" + REF_PAGE + "' or '" + REF_SITE + "'"); } } public String getTarget() { return (this.target); } public void setTarget(String target) { this.target = target; } /** * Process the start of this tag. * * @throws JspException if a JSP exception has occurred */ public int doStartTag() throws JspException { HttpServletRequest request = (HttpServletRequest) pageContext.getRequest(); String serverName = (this.server == null) ? request.getServerName() : this.server; int port = request.getServerPort(); String headerHost = request.getHeader("Host"); if ((serverName == null) && (headerHost != null)) { StringTokenizer tokenizer = new StringTokenizer(headerHost, ":"); serverName = tokenizer.nextToken(); if (tokenizer.hasMoreTokens()) { String portS = tokenizer.nextToken(); try { port = Integer.parseInt(portS); } catch (Exception e) { port = 80; } } else { port = 80; } } String baseTag = renderBaseElement(request.getScheme(), serverName, port, request.getRequestURI()); JspWriter out = pageContext.getOut(); try { out.write(baseTag); } catch (IOException e) { pageContext.setAttribute(Globals.EXCEPTION_KEY, e, PageContext.REQUEST_SCOPE); throw new JspException(messages.getMessage("common.io", e.toString())); } return EVAL_BODY_INCLUDE; } /** * Render a fully formed HTML <base> element and return it as a * String. * * @param scheme The scheme used in the url (ie. http or https). * @param serverName * @param port * @param uri The portion of the url from the protocol name up to * the query string. * @return String An HTML <base> element. * @since Struts 1.1 */ protected String renderBaseElement(String scheme, String serverName, int port, String uri) { StringBuffer tag = new StringBuffer("<base href=\""); if (ref.equals(REF_SITE)) { StringBuffer contextBase = new StringBuffer(((HttpServletRequest) pageContext.getRequest()) .getContextPath()); contextBase.append("/"); tag.append(RequestUtils.createServerUriStringBuffer(scheme, serverName, port, contextBase.toString()).toString()); } else { tag.append(RequestUtils.createServerUriStringBuffer(scheme, serverName, port, uri).toString()); } tag.append("\""); if (this.target != null) { tag.append(" target=\""); tag.append(this.target); tag.append("\""); } if (TagUtils.getInstance().isXhtml(this.pageContext)) { tag.append(" />"); } else { tag.append(">"); } return tag.toString(); } /** * Returns the server. * * @return String */ public String getServer() { return this.server; } /** * Sets the server. * * @param server The server to set */ public void setServer(String server) { this.server = server; } }