Java tutorial
package org.apache.struts.scaffold; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.struts.action.ActionError; import org.apache.struts.action.ActionErrors; import org.apache.struts.action.ActionForm; import org.apache.struts.action.ActionForward; import org.apache.struts.action.ActionMapping; import org.apache.commons.scaffold.lang.Tokens; /** * Remove an object from the user's session. * The name of the attribute is passed via the parameter property. * * @author Ted Husted * @version $Revision: 1.4 $ $Date: 2002/12/08 08:14:29 $ */ public final class RemoveAttributeAction extends BaseAction { /** * // :FIXME: Needs to be tested.<p> * Attempt to remove an attribute from a servlet context. * Find "success" if attribute exists, or "failure" if not. * * The servlet context and attributes are specified as the * parameters property, seperated by semi-colons * [parameter="application;HOURS]. * non-error state. * * To indicate that all scopes are to be checked, * specify an asterisk instead of the scope name * [parameter="*;HOURS]. The attribute will be removed * from <b>only</b> the first context found. * * If both parameters are not given, an error is set. * * @param mapping The ActionMapping used to select this instance * @param form The optional ActionForm bean for this request * @param request The HTTP request we are processing * @param response The response we are creating * @todo Add support for multiple attributes * @fixme Needs to be tested. */ protected ActionForward findSuccess(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) { String[] parameters = tokenize(mapping.getParameter()); // If not 2+ parameters, bail if (2 > parameters.length) { ActionErrors errors = new ActionErrors(); errors.add(ActionErrors.GLOBAL_ERROR, new ActionError(Tokens.PROCESS_MISSING_PARAMETER)); saveErrors(request, errors); return mapping.findForward(Tokens.FAILURE); } String scope = parameters[0]; Object bean = null; String name = parameters[1]; // :TODO: Add support for multiple attributes boolean any = ("*".equals(scope)); if (any) { bean = request.getAttribute(name); if (null != bean) request.removeAttribute(name); if (null == bean) { bean = request.getSession().getAttribute(name); if (null != bean) request.getSession().removeAttribute(name); } if (null == bean) { bean = servlet.getServletContext().getAttribute(name); if (null != bean) servlet.getServletContext().removeAttribute(name); } } // end any else { if (Tokens.REQUEST.equals(scope)) { bean = request.getAttribute(name); request.removeAttribute(name); } if (Tokens.SESSION.equals(scope)) { bean = request.getSession().getAttribute(name); request.getSession().removeAttribute(name); } if (Tokens.APPLICATION.equals(scope)) { bean = servlet.getServletContext().getAttribute(name); servlet.getServletContext().removeAttribute(name); } } // end !any if (null == bean) { return mapping.findForward(Tokens.FAILURE); } return mapping.findForward(Tokens.SUCCESS); } } // end RemoveAttribute /* * ==================================================================== * * The Apache Software License, Version 1.1 * * Copyright (c) 2001 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", "Scaffold", 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/>. * */