001: /* ====================================================================
002: * The Jcorporate Apache Style Software License, Version 1.2 05-07-2002
003: *
004: * Copyright (c) 1995-2002 Jcorporate Ltd. All rights reserved.
005: *
006: * Redistribution and use in source and binary forms, with or without
007: * modification, are permitted provided that the following conditions
008: * are met:
009: *
010: * 1. Redistributions of source code must retain the above copyright
011: * notice, this list of conditions and the following disclaimer.
012: *
013: * 2. Redistributions in binary form must reproduce the above copyright
014: * notice, this list of conditions and the following disclaimer in
015: * the documentation and/or other materials provided with the
016: * distribution.
017: *
018: * 3. The end-user documentation included with the redistribution,
019: * if any, must include the following acknowledgment:
020: * "This product includes software developed by Jcorporate Ltd.
021: * (http://www.jcorporate.com/)."
022: * Alternately, this acknowledgment may appear in the software itself,
023: * if and wherever such third-party acknowledgments normally appear.
024: *
025: * 4. "Jcorporate" and product names such as "Expresso" must
026: * not be used to endorse or promote products derived from this
027: * software without prior written permission. For written permission,
028: * please contact info@jcorporate.com.
029: *
030: * 5. Products derived from this software may not be called "Expresso",
031: * or other Jcorporate product names; nor may "Expresso" or other
032: * Jcorporate product names appear in their name, without prior
033: * written permission of Jcorporate Ltd.
034: *
035: * 6. No product derived from this software may compete in the same
036: * market space, i.e. framework, without prior written permission
037: * of Jcorporate Ltd. For written permission, please contact
038: * partners@jcorporate.com.
039: *
040: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
041: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
042: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
043: * DISCLAIMED. IN NO EVENT SHALL JCORPORATE LTD OR ITS CONTRIBUTORS
044: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
045: * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
046: * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
047: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
048: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
049: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
050: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
051: * SUCH DAMAGE.
052: * ====================================================================
053: *
054: * This software consists of voluntary contributions made by many
055: * individuals on behalf of the Jcorporate Ltd. Contributions back
056: * to the project(s) are encouraged when you make modifications.
057: * Please send them to support@jcorporate.com. For more information
058: * on Jcorporate Ltd. and its products, please see
059: * <http://www.jcorporate.com/>.
060: *
061: * Portions of this software are based upon other open source
062: * products and are subject to their respective licenses.
063: */
064:
065: package com.jcorporate.expresso.core.servlet.viewhandler;
066:
067: import com.jcorporate.expresso.core.ExpressoConstants;
068: import com.jcorporate.expresso.core.controller.ControllerException;
069: import com.jcorporate.expresso.core.controller.ControllerResponse;
070: import com.jcorporate.expresso.core.controller.NonHandleableException;
071: import com.jcorporate.expresso.core.servlet.DBServlet;
072: import org.apache.log4j.Logger;
073:
074: import javax.servlet.ServletException;
075: import javax.servlet.http.HttpServletRequest;
076: import javax.servlet.http.HttpServletResponse;
077: import java.io.IOException;
078:
079: public abstract class ViewHandler extends DBServlet {
080: private static Logger log = Logger.getLogger(ViewHandler.class);
081:
082: public ViewHandler() {
083: }
084:
085: /**
086: * The ViewHandler implementation must implement only this method
087: */
088: public abstract void handleView(ControllerResponse con,
089: HttpServletRequest req, HttpServletResponse res)
090: throws ServletException, IOException, ControllerException,
091: NonHandleableException;
092:
093: /* doController(HttpServletRequest, HttpServletResponse, Hashtable) */
094: /**
095: * Both GET and POST for the ViewHandler simply pass the information
096: * from parameters and form fields on to the named controller object.
097: * The Controller object passes back a series of Inputs, Outputs
098: * and Actions that are a result of the requested Controller
099: *
100: * @param request Standard request object
101: * @param response Standard response object
102: * @throws ServletException If an uncaught exception occurs
103: * @throws IOException If an I/O error occurs while communicating with
104: * the client
105: */
106: public void doGet(HttpServletRequest request,
107: HttpServletResponse response) throws ServletException,
108: IOException {
109: super .doGet(request, response);
110: log.debug("ViewHandler Begins in Get method");
111: process(request, response);
112: } /* doGet(HttpServletRequest, HttpServletResponse) */
113:
114: /**
115: * Handle POST method, typically from a form. The only difference between
116: * get and post in this servlet is that when processing post, we look
117: * for a parameter with a name of the form "button_xxx", where xxx is
118: * the next state, as the state to controller into might vary depending on
119: * what button the user presses.
120: *
121: * @param req Standard request object
122: * @param res Standard response object
123: * @throws ServletException If an uncaught exception occurs
124: * @throws IOException If an I/O error occurs while communicating with
125: * the client
126: */
127: public void doPost(HttpServletRequest req, HttpServletResponse res)
128: throws ServletException, IOException {
129: super .doPost(req, res);
130: log.debug("ViewHandler Begins in Post method");
131: process(req, res);
132: } /* doPost(HttpServletRequest, HttpServletResponse) */
133:
134: public String getTitle() {
135: return ("View Handler Servlet");
136: }
137:
138: /**
139: * This is a master method that is does the processing for both GET
140: * and POST.
141: * <p/>
142: * <p/>
143: * Creation date: (1/10/01 8:38:52 AM)
144: * author Adam Rossi, PlatinumSolutions
145: *
146: * @param request javax.servlet.http.HttpServletRequest
147: * @param response javax.servlet.http.HttpServletResponse
148: */
149: public void process(HttpServletRequest request,
150: HttpServletResponse response) throws ServletException,
151: IOException {
152: ControllerResponse res = (ControllerResponse) request
153: .getAttribute(ExpressoConstants.CONTROLLER_RESPONSE_KEY);
154:
155: if (res == null) {
156: throw new ServletException(
157: "No Controller Response found in request");
158: }
159: try {
160: handleView(res, request, response);
161: } catch (ControllerException ce) {
162: throw new ServletException(ce);
163: } catch (NonHandleableException ce) {
164: throw new ServletException(ce);
165: }
166: }
167: }
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