Environment


1   /*
2    * Copyright 1999-2004 The Apache Software Foundation.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.apache.cocoon.environment;
17  
18  import java.io.IOException  ;
19  import java.io.OutputStream  ;
20  import java.util.Enumeration  ;
21  import java.util.Map  ;
22  
23  /**
24   * Base interface for an environment abstraction
25   *
26   * @author <a HREF="mailto:bluetkemeier@s-und-n.de">Bj&ouml;rn L&uuml;tkemeier</a>
27   * @author <a HREF="mailto:Giacomo.Pati@pwr.ch">Giacomo Pati</a>
28   * @author <a HREF="mailto:cziegeler@apache.org">Carsten Ziegeler</a>
29   * @version CVS $Id: Environment.java 30932 2004-07-29 17:35:38Z vgritsenko $
30   */
31  public interface Environment
32      extends SourceResolver {
33  
34      /**
35       * Get the URI to process. The prefix is stripped off.
36       */
37      String   getURI();
38  
39      /**
40       * Get the prefix of the URI in progress.
41       */
42      String   getURIPrefix();
43  
44      /**
45       * Get the Root Context
46       */
47      String   getRootContext();
48  
49      /**
50       * Get current context
51       */
52      String   getContext();
53  
54      /**
55       * Get the view to process
56       */
57      String   getView();
58  
59      /**
60       * Get the action to process
61       */
62      String   getAction();
63  
64      /**
65       * Set the context. This is similar to changeContext()
66       * except that it is absolute.
67       */
68      void setContext(String   prefix, String   uri, String   context);
69  
70      /**
71       * Change the context from uriprefix to context
72       */
73      void changeContext(String   uriprefix, String   context) throws Exception  ;
74  
75      /**
76       * Redirect to the given URL
77       */
78      void redirect(boolean sessionmode, String   url) throws IOException  ;
79  
80      /**
81       * Set the content type of the generated resource
82       */
83      void setContentType(String   mimeType);
84  
85      /**
86       * Get the content type of the resource
87       */
88      String   getContentType();
89  
90      /**
91       * Set the length of the generated content
92       */
93      void setContentLength(int length);
94  
95      /**
96       * Set the response status code
97       */
98      void setStatus(int statusCode);
99  
100     /**
101      * Get the output stream where to write the generated resource.
102      * @deprecated Use {@link #getOutputStream(int)} instead.
103      */
104     OutputStream   getOutputStream() throws IOException  ;
105 
106     /**
107      * Get the output stream where to write the generated resource.
108      * The returned stream is buffered by the environment. If the
109      * buffer size is -1 then the complete output is buffered.
110      * If the buffer size is 0, no buffering takes place.
111      * This method replaces {@link #getOutputStream()}.
112      */
113     OutputStream   getOutputStream(int bufferSize) throws IOException  ;
114 
115     /**
116      * Get the underlying object model
117      */
118     Map   getObjectModel();
119 
120     /**
121      * Check if the response has been modified since the same
122      * "resource" was requested.
123      * The caller has to test if it is really the same "resource"
124      * which is requested.
125      * @return true if the response is modified or if the
126      *         environment is not able to test it
127      */
128     boolean isResponseModified(long lastModified);
129 
130     /**
131      * Mark the response as not modified.
132      */
133     void setResponseIsNotModified();
134 
135     /**
136      * Binds an object to this environment, using the name specified. This allows
137      * the pipeline assembly engine to store for its own use objects that souldn't
138      * be exposed to other components (generators, selectors, etc) and therefore
139      * cannot be put in the object model.
140      * <p>
141      * If an object of the same name is already bound, the object is replaced.
142      *
143      * @param name  the name to which the object is bound
144      * @param value the object to be bound
145      */
146     void setAttribute(String   name, Object   value);
147 
148     /**
149      * Returns the object bound with the specified name, or <code>null</code>
150      * if no object is bound under the name.
151      *
152      * @param name                a string specifying the name of the object
153      * @return                    the object with the specified name
154      */
155     Object   getAttribute(String   name);
156 
157     /**
158      * Removes the object bound with the specified name from
159      * this environment. If the environment does not have an object
160      * bound with the specified name, this method does nothing.
161      *
162      * @param name the name of the object to remove
163      */
164     void removeAttribute(String   name);
165 
166     /**
167      * Returns an <code>Enumeration</code> of <code>String</code> objects
168      * containing the names of all the objects bound to this environment.
169      *
170      * @return an <code>Enumeration</code> of <code>String</code>s.
171      */
172     Enumeration   getAttributeNames();
173 
174     /**
175      * Reset the response if possible. This allows error handlers to have
176      * a higher chance to produce clean output if the pipeline that raised
177      * the error has already output some data.
178      * If a buffered output stream is used, resetting is always successful.
179      *
180      * @return true if the response was successfully reset
181      */
182     boolean tryResetResponse() throws IOException  ;
183 
184 
185     /**
186      * Commit the response
187      */
188     void commitResponse() throws IOException  ;
189     
190     /**
191      * Notify that the processing starts.
192      */
193     void startingProcessing();
194     
195     /**
196      * Notify that the processing is finished
197      * This can be used to cleanup the environment object
198      */
199     void finishingProcessing();
200     
201     /**
202      * Is this environment external ? An external environment is one that 
203      * is created in response to an external request (http, commandline, etc.). 
204      * Environments created by the "cocoon:" protocol aren't external.
205      * 
206      * @return true if this environment is external
207      */
208     boolean isExternal();
209     
210     /**
211      * Is this an internal redirect?
212      * An environment is on internal redirect if it is an internal request
213      * (via the cocoon: protocol) and used for a redirect.
214      */
215     boolean isInternalRedirect();
216 }
217 
218
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags