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Java > Open Source Codes > com > jcorporate > expresso > core > servlet > viewhandler > JSPViewHandler


1 /* ====================================================================
2  * The Jcorporate Apache Style Software License, Version 1.2 05-07-2002
3  *
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61  * Portions of this software are based upon other open source
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63  */
64
65 package com.jcorporate.expresso.core.servlet.viewhandler;
66
67 import com.jcorporate.expresso.core.controller.ControllerException;
68 import com.jcorporate.expresso.core.controller.ControllerResponse;
69 import com.jcorporate.expresso.core.controller.NonHandleableException;
70 import com.jcorporate.expresso.core.jsdkapi.GenericDispatcher;
71 import com.jcorporate.expresso.core.misc.StringUtil;
72 import org.apache.log4j.Logger;
73
74 import javax.servlet.ServletException JavaDoc;
75 import javax.servlet.http.HttpServletRequest JavaDoc;
76 import javax.servlet.http.HttpServletResponse JavaDoc;
77 import java.io.IOException JavaDoc;
78 import java.util.Vector JavaDoc;
79
80
81 /**
82  * Special servlet designed to interact with server-side Controller objects
83  *
84  * @author Michael Nash
85  */
86 public class JSPViewHandler
87         extends ViewHandler {
88     private static Logger log = Logger.getLogger(JSPViewHandler.class);
89
90     /**
91      * Process a Controller with an explicitly specified "view"
92      */
93     public void handleView(ControllerResponse con, HttpServletRequest JavaDoc req,
94                            HttpServletResponse JavaDoc res)
95             throws ServletException JavaDoc, IOException JavaDoc, ControllerException,
96             NonHandleableException {
97         if (con.isCustomResponse()) {
98             return;
99         }
100
101         String JavaDoc view = StringUtil.notNull(con.getParameter("view"));
102
103         if (view.equals("")) {
104             view = StringUtil.notNull(con.getParameter("next"));
105         }
106         if (!view.equals("")) {
107
108             /* check to see that there is something from the controller */
109             Vector JavaDoc inputs = con.getInputs();
110             Vector JavaDoc outputs = con.getOutputs();
111             Vector JavaDoc actions = con.getTransitions();
112             Vector JavaDoc blocks = con.getBlocks();
113
114             if ((inputs == null) && (outputs == null) && (actions == null) &&
115                     (blocks == null)) {
116                 throw new ServletException JavaDoc("No input, output or " +
117                         "actions returned by this Controller");
118             }
119         }
120
121         /* stash the response object in the session
122         REMOVED 10/2003 because everywhere else, response is added as attribute within request scope, not session scope. LAH */
123 // GenericSession.setAttribute(req, "controllerResponse", con);
124
125         /* if we didn't get redirected above, now we go somewhere... */
126         /* if there was a "next" parameter supplied... */
127         if (!view.equals("")) {
128             if (log.isDebugEnabled()) {
129                 log.debug("Going to 'next/view' URL of '" + view +
130                         "' (relative to web-app context root)");
131             }
132             try {
133                 GenericDispatcher.forward(req, res, res.encodeURL(view));
134             } catch (Exception JavaDoc ee) {
135                 log.error("Error forwarding to '" + res.encodeURL(view) + "'",
136                         ee);
137                 throw new NonHandleableException(ee);
138             }
139         }
140     } /* doController(HttpServletRequest, HttpServletResponse, Hashtable) */
141
142 }
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