001: /*
002: * Copyright (c) 2003 The Visigoth Software Society. All rights
003: * reserved.
004: *
005: * Redistribution and use in source and binary forms, with or without
006: * modification, are permitted provided that the following conditions
007: * are met:
008: *
009: * 1. Redistributions of source code must retain the above copyright
010: * notice, this list of conditions and the following disclaimer.
011: *
012: * 2. Redistributions in binary form must reproduce the above copyright
013: * notice, this list of conditions and the following disclaimer in
014: * the documentation and/or other materials provided with the
015: * distribution.
016: *
017: * 3. The end-user documentation included with the redistribution, if
018: * any, must include the following acknowledgement:
019: * "This product includes software developed by the
020: * Visigoth Software Society (http://www.visigoths.org/)."
021: * Alternately, this acknowledgement may appear in the software itself,
022: * if and wherever such third-party acknowledgements normally appear.
023: *
024: * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
025: * project contributors may be used to endorse or promote products derived
026: * from this software without prior written permission. For written
027: * permission, please contact visigoths@visigoths.org.
028: *
029: * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
030: * nor may "FreeMarker" or "Visigoth" appear in their names
031: * without prior written permission of the Visigoth Software Society.
032: *
033: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
034: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
035: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
036: * DISCLAIMED. IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
037: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
038: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
039: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
040: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
041: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
042: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
043: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
044: * SUCH DAMAGE.
045: * ====================================================================
046: *
047: * This software consists of voluntary contributions made by many
048: * individuals on behalf of the Visigoth Software Society. For more
049: * information on the Visigoth Software Society, please see
050: * http://www.visigoths.org/
051: */
052:
053: package freemarker.ext.servlet;
054:
055: import java.io.Serializable;
056:
057: import javax.servlet.http.HttpServletRequest;
058: import javax.servlet.http.HttpServletResponse;
059: import javax.servlet.http.HttpSession;
060:
061: import freemarker.template.ObjectWrapper;
062: import freemarker.template.TemplateHashModel;
063: import freemarker.template.TemplateModel;
064: import freemarker.template.TemplateModelException;
065:
066: /**
067: * TemplateHashModel wrapper for a HttpSession attributes.
068: * @author Attila Szegedi
069: * @version $Id: HttpSessionHashModel.java,v 1.14.4.1 2006/04/19 16:16:43 szegedia Exp $
070: */
071:
072: public final class HttpSessionHashModel implements TemplateHashModel,
073: Serializable {
074: private static final long serialVersionUID = 1L;
075: private transient HttpSession session;
076: private transient final ObjectWrapper wrapper;
077:
078: // These are required for lazy initializing session
079: private transient final FreemarkerServlet servlet;
080: private transient final HttpServletRequest request;
081: private transient final HttpServletResponse response;
082:
083: /**
084: * Use this constructor when the session already exists.
085: * @param session the session
086: * @param wrapper an object wrapper used to wrap session attributes
087: */
088: public HttpSessionHashModel(HttpSession session,
089: ObjectWrapper wrapper) {
090: this .session = session;
091: this .wrapper = wrapper;
092:
093: this .servlet = null;
094: this .request = null;
095: this .response = null;
096: }
097:
098: /**
099: * Use this constructor when the session isn't already created. It is passed
100: * enough parameters so that the session can be properly initialized after
101: * it is detected that it was created.
102: * @param servlet the FreemarkerServlet that created this model. If the
103: * model is not created through FreemarkerServlet, leave this argument as
104: * null.
105: * @param request the actual request
106: * @param response the actual response
107: * @param wrapper an object wrapper used to wrap session attributes
108: */
109: public HttpSessionHashModel(FreemarkerServlet servlet,
110: HttpServletRequest request, HttpServletResponse response,
111: ObjectWrapper wrapper) {
112: this .wrapper = wrapper;
113:
114: this .servlet = servlet;
115: this .request = request;
116: this .response = response;
117: }
118:
119: public TemplateModel get(String key) throws TemplateModelException {
120: checkSessionExistence();
121: return wrapper.wrap(session != null ? session.getAttribute(key)
122: : null);
123: }
124:
125: private void checkSessionExistence() throws TemplateModelException {
126: if (session == null && request != null) {
127: session = request.getSession(false);
128: if (session != null && servlet != null) {
129: try {
130: servlet.initializeSession(request, response);
131: } catch (Exception e) {
132: throw new TemplateModelException(e);
133: }
134: }
135: }
136: }
137:
138: boolean isZombie() {
139: return session == null && request == null;
140: }
141:
142: public boolean isEmpty() throws TemplateModelException {
143: checkSessionExistence();
144: return session == null
145: || !session.getAttributeNames().hasMoreElements();
146: }
147: }
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