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Java > Open Source Codes > org > objectstyle > cayenne > conf > BasicServletConfiguration


1 /* ====================================================================
2  *
3  * The ObjectStyle Group Software License, version 1.1
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56 package org.objectstyle.cayenne.conf;
57
58 import javax.servlet.ServletContext JavaDoc;
59 import javax.servlet.http.HttpSession JavaDoc;
60
61 import org.apache.log4j.Logger;
62 import org.objectstyle.cayenne.access.DataContext;
63 import org.objectstyle.cayenne.util.ResourceLocator;
64 import org.objectstyle.cayenne.util.WebApplicationResourceLocator;
65
66 /**
67  * BasicServletConfiguration is a Configuration that uses ServletContext to locate
68  * resources. This class can only be used in a context of a servlet/jsp container. It
69  * resolves configuration file paths relative to the web application "WEB-INF" directory.
70  * <p>
71  * BasicServletConfiguration is compatible with Servlet Specification 2.2 and higher. Also
72  * look at ServletConfiguration for the information how to utilize listeners introduced in
73  * Servlet Specification 2.3.
74  * </p>
75  *
76  * @author Andrei Adamchik
77  * @author Scott Finnerty
78  * @deprecated Since 1.2 ServletUtil is used instead, as the actual file loading strategy
79  * is defined at the ResourceLocator elevel, and this class provides no value
80  * of its own.
81  */
82 public class BasicServletConfiguration extends DefaultConfiguration {
83     private static Logger logObj = Logger.getLogger(BasicServletConfiguration.class);
84
85     public static final String JavaDoc CONFIGURATION_PATH_KEY =
86         "cayenne.configuration.path";
87     public static final String JavaDoc DATA_CONTEXT_KEY = "cayenne.datacontext";
88
89     protected ServletContext JavaDoc servletContext;
90
91     public synchronized static BasicServletConfiguration initializeConfiguration(ServletContext JavaDoc ctxt) {
92         // check if this web application already has a servlet configuration
93 // sometimes multiple initializations are done by mistake...
94
95         // Andrus: are there any cases when reinitialization is absolutely required?
96
97         // don't use static getter, since it will do initialization on demand!!!
98 Configuration oldConfiguration = Configuration.sharedConfiguration;
99         if (oldConfiguration instanceof BasicServletConfiguration) {
100             BasicServletConfiguration basicConfiguration =
101                 (BasicServletConfiguration) oldConfiguration;
102             if (basicConfiguration.getServletContext() == ctxt) {
103                 logObj.info(
104                     "BasicServletConfiguration is already initialized, reusing.");
105                 return basicConfiguration;
106             }
107         }
108
109         BasicServletConfiguration conf = new BasicServletConfiguration(ctxt);
110         Configuration.initializeSharedConfiguration(conf);
111
112         return conf;
113     }
114
115     /**
116      * Returns default Cayenne DataContext associated with the HttpSession.
117      * If no DataContext exists in the session, it is created on the spot.
118      */
119     public static DataContext getDefaultContext(HttpSession JavaDoc session) {
120         synchronized (session) {
121             DataContext ctxt =
122                 (DataContext) session.getAttribute(DATA_CONTEXT_KEY);
123
124             if (ctxt == null) {
125                 ctxt = DataContext.createDataContext();
126                 session.setAttribute(
127                     BasicServletConfiguration.DATA_CONTEXT_KEY,
128                     ctxt);
129             }
130
131             return ctxt;
132         }
133     }
134
135     public BasicServletConfiguration() {
136         super();
137
138     }
139
140     public BasicServletConfiguration(ServletContext JavaDoc ctxt) {
141         super();
142         this.setServletContext(ctxt);
143
144         ResourceLocator l = new WebApplicationResourceLocator(servletContext);
145         l.setSkipAbsolutePath(true);
146         l.setSkipClasspath(false);
147         l.setSkipCurrentDirectory(true);
148         l.setSkipHomeDirectory(true);
149
150         // check for a configuration path in the context parameters
151 String JavaDoc configurationPath =
152             ctxt.getInitParameter(CONFIGURATION_PATH_KEY);
153         if (configurationPath != null
154             && configurationPath.trim().length() > 0) {
155             l.addFilesystemPath(configurationPath);
156         }
157
158         this.setResourceLocator(l);
159     }
160
161     /**
162      * Sets the servletContext.
163      * @param servletContext The servletContext to set
164      */
165     public void setServletContext(ServletContext JavaDoc servletContext) {
166         this.servletContext = servletContext;
167     }
168
169     /** Returns current application context object. */
170     public ServletContext JavaDoc getServletContext() {
171         return servletContext;
172     }
173
174     public boolean canInitialize() {
175         return (getServletContext() != null);
176     }
177 }
178
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