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Java > Open Source Codes > org > infohazard > maverick > view > DispatchedViewFactory


1 /*
2  * $Id: DispatchedViewFactory.java,v 1.7 2004/06/07 20:38:17 eelco12 Exp $
3  * $Source: /cvsroot/mav/maverick/src/java/org/infohazard/maverick/view/DispatchedViewFactory.java,v $
4  */
5
6 package org.infohazard.maverick.view;
7
8 import java.io.IOException JavaDoc;
9 import java.util.Iterator JavaDoc;
10 import java.util.Map JavaDoc;
11
12 import javax.servlet.RequestDispatcher JavaDoc;
13 import javax.servlet.ServletConfig JavaDoc;
14 import javax.servlet.ServletException JavaDoc;
15
16 import org.apache.commons.logging.Log;
17 import org.apache.commons.logging.LogFactory;
18 import org.infohazard.maverick.flow.ConfigException;
19 import org.infohazard.maverick.flow.TransformStep;
20 import org.infohazard.maverick.flow.View;
21 import org.infohazard.maverick.flow.ViewContext;
22 import org.infohazard.maverick.flow.ViewFactory;
23 import org.infohazard.maverick.util.XML;
24 import org.jdom.Element;
25
26
27 /**
28  * <p>This factory creates Views which use the RequestDispatcher to obtain
29  * content. It is used by the DocumentViewFactory and not intended to be
30  * designated as a normal Maverick view type.</p>
31  */
32 public class DispatchedViewFactory implements ViewFactory
33 {
34     /**
35      * Logger.
36      */
37     private static Log log = LogFactory.getLog(DispatchedViewFactory.class);
38
39     /**
40      * Initialize.
41      * @see org.infohazard.maverick.flow.ViewFactory#init(org.jdom.Element, javax.servlet.ServletConfig)
42      */
43     public void init(Element factoryNode, ServletConfig JavaDoc servletCfg) throws ConfigException
44     {
45     }
46
47     /**
48      * @see org.infohazard.maverick.flow.ViewFactory#createView(org.jdom.Element)
49      */
50     public View createView(Element viewNode) throws ConfigException
51     {
52         String JavaDoc path = XML.getValue(viewNode, "path");
53
54         if (path == null)
55             throw new ConfigException("View node must have a path: " + XML.toString(viewNode));
56             
57         return new DispatchedView(path);
58     }
59
60     /**
61      * The view is rendered as a RequestDispatcher.forward() or include().
62      */
63     protected static class DispatchedView implements View
64     {
65         /**
66          * Source url of the document.
67          */
68         protected String JavaDoc path;
69         
70         /**
71          * @param path is the URL of the document to render.
72          */
73         public DispatchedView(String JavaDoc path)
74         {
75             if (path.startsWith("/"))
76                 this.path = path;
77             else
78                 this.path = "/" + path;
79     
80             log.debug("Creating DispatchedView with path: " + path);
81         }
82     
83         /**
84          * Renders the url associated with this view directly to the response.
85          *
86          * @see View#go
87          */
88         public void go(ViewContext vctx) throws IOException JavaDoc, ServletException JavaDoc
89         {
90             // Put any params in the request attributes
91 if (vctx.getViewParams() != null)
92             {
93                 if (log.isDebugEnabled())
94                     log.debug("Setting " + vctx.getViewParams().size() + " params");
95                 
96                 Iterator JavaDoc entryIt = vctx.getViewParams().entrySet().iterator();
97                 while (entryIt.hasNext())
98                 {
99                     Map.Entry JavaDoc entry = (Map.Entry JavaDoc)entryIt.next();
100                     vctx.getRequest().setAttribute((String JavaDoc)entry.getKey(), entry.getValue());
101                 }
102             }
103             
104             RequestDispatcher JavaDoc disp = vctx.getRequest().getRequestDispatcher(this.path);
105             if (null == disp)
106                 throw new ServletException JavaDoc("RequestDispatcher could not be created for " + this.path);
107
108             TransformStep next = vctx.getNextStep();
109
110             if (log.isDebugEnabled())
111                 log.debug((next.isLast() ? "Forwarding to " : "Including ") + this.path);
112                 
113             if (next.isLast())
114                 disp.forward(vctx.getRequest(), next.getResponse());
115             else
116                 disp.include(vctx.getRequest(), next.getResponse());
117
118             next.done();
119         }
120     }
121 }
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