home | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Spring Framework example source code file (RequestContextAwareTag.java)

This example Spring Framework source code file (RequestContextAwareTag.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Spring Framework tags/keywords

exception, exception, http, jsp, jspexception, jspexception, request_context_page_attribute, requestcontext, requestcontext, requestcontextawaretag, runtimeexception, servlet, string, string, tagsupport, throwable, trycatchfinally

The Spring Framework RequestContextAwareTag.java source code

 * Copyright 2002-2006 the original author or authors.
 * 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,
 * See the License for the specific language governing permissions and
 * limitations under the License.

package org.springframework.web.servlet.tags;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.tagext.TagSupport;
import javax.servlet.jsp.tagext.TryCatchFinally;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.web.servlet.support.JspAwareRequestContext;
import org.springframework.web.servlet.support.RequestContext;

 * Superclass for all tags that require a {@link RequestContext}.
 * <p>The RequestContext instance provides easy access
 * to current state like the
 * {@link org.springframework.web.context.WebApplicationContext},
 * the {@link java.util.Locale}, the
 * {@link org.springframework.ui.context.Theme}, etc.
 * <p>Mainly intended for
 * {@link org.springframework.web.servlet.DispatcherServlet} requests;
 * will use fallbacks when used outside <code>DispatcherServlet.
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @see org.springframework.web.servlet.support.RequestContext
 * @see org.springframework.web.servlet.DispatcherServlet
public abstract class RequestContextAwareTag extends TagSupport implements TryCatchFinally {

	/** {@link javax.servlet.jsp.PageContext} attribute for page-level
	 * {@link RequestContext} instance.
	 * */
	public static final String REQUEST_CONTEXT_PAGE_ATTRIBUTE =

	/** Logger available to subclasses */
	protected final Log logger = LogFactory.getLog(getClass());

	private RequestContext requestContext;

	 * Create and expose the current RequestContext.
	 * Delegates to {@link #doStartTagInternal()} for actual work.
	 * @see org.springframework.web.servlet.support.JspAwareRequestContext
	public final int doStartTag() throws JspException {
		this.requestContext = (RequestContext) this.pageContext.getAttribute(REQUEST_CONTEXT_PAGE_ATTRIBUTE);
		try {
			if (this.requestContext == null) {
				this.requestContext = new JspAwareRequestContext(this.pageContext);
				this.pageContext.setAttribute(REQUEST_CONTEXT_PAGE_ATTRIBUTE, this.requestContext);
			return doStartTagInternal();
		catch (JspException ex) {
			logger.error(ex.getMessage(), ex);
			throw ex;
		catch (RuntimeException ex) {
			logger.error(ex.getMessage(), ex);
			throw ex;
		catch (Exception ex) {
			logger.error(ex.getMessage(), ex);
			throw new JspTagException(ex.getMessage());

	 * Return the current RequestContext.
	protected final RequestContext getRequestContext() {
		return this.requestContext;

	 * Called by doStartTag to perform the actual work.
	 * @return same as TagSupport.doStartTag
	 * @throws Exception any exception, any checked one other than
	 * a JspException gets wrapped in a JspException by doStartTag
	 * @see javax.servlet.jsp.tagext.TagSupport#doStartTag
	protected abstract int doStartTagInternal() throws Exception;

	public void doCatch(Throwable throwable) throws Throwable {
		throw throwable;

	public void doFinally() {
		this.requestContext = null;


Other Spring Framework examples (source code examples)

Here is a short list of links related to this Spring Framework RequestContextAwareTag.java source code file:

my book on functional programming


new blog posts


Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.