001 /*
002 * CDDL HEADER START
003 *
004 * The contents of this file are subject to the terms of the
005 * Common Development and Distribution License, Version 1.0 only
006 * (the "License"). You may not use this file except in compliance
007 * with the License.
008 *
009 * You can obtain a copy of the license at
010 * docs/licenses/cddl.txt
011 * or http://www.opensource.org/licenses/cddl1.php.
012 * See the License for the specific language governing permissions
013 * and limitations under the License.
014 *
015 * When distributing Covered Code, include this CDDL HEADER in each
016 * file and include the License file at
017 * docs/licenses/cddl.txt. If applicable,
018 * add the following below this CDDL HEADER, with the fields enclosed
019 * by brackets "[]" replaced with your own identifying information:
020 * Portions Copyright [yyyy] [name of copyright owner]
021 *
022 * CDDL HEADER END
023 *
024 *
025 * Copyright 2011-2013 UnboundID Corp.
026 */
027 package com.unboundid.directory.sdk.http.api;
028
029
030
031 import java.util.Collections;
032 import java.util.List;
033 import java.util.Map;
034
035 import javax.servlet.Filter;
036 import javax.servlet.http.HttpServlet;
037
038 import com.unboundid.directory.sdk.broker.internal.IdentityBrokerExtension;
039 import com.unboundid.directory.sdk.common.internal.ExampleUsageProvider;
040 import com.unboundid.directory.sdk.common.internal.Reconfigurable;
041 import com.unboundid.directory.sdk.common.internal.UnboundIDExtension;
042 import com.unboundid.directory.sdk.ds.internal.DirectoryServerExtension;
043 import com.unboundid.directory.sdk.http.config.HTTPServletExtensionConfig;
044 import com.unboundid.directory.sdk.http.types.HTTPServerContext;
045 import com.unboundid.directory.sdk.metrics.internal.MetricsEngineExtension;
046 import com.unboundid.directory.sdk.proxy.internal.DirectoryProxyServerExtension;
047 import com.unboundid.ldap.sdk.LDAPException;
048 import com.unboundid.ldap.sdk.ResultCode;
049 import com.unboundid.util.Extensible;
050 import com.unboundid.util.ThreadSafety;
051 import com.unboundid.util.ThreadSafetyLevel;
052 import com.unboundid.util.args.ArgumentException;
053 import com.unboundid.util.args.ArgumentParser;
054
055
056
057 /**
058 * This class defines an API that must be implemented by extensions which create
059 * servlets for use with an HTTP connection handler.
060 * <BR>
061 * <H2>Configuring HTTP Servlet Extensions</H2>
062 * In order to configure an HTTP servlet extension created using this API, use a
063 * command like:
064 * <PRE>
065 * dsconfig create-http-servlet-extension \
066 * --extension-name "<I>{extension-name}</I>" \
067 * --type third-party \
068 * --set enabled:true \
069 * --set "extension-class:<I>{class-name}</I>" \
070 * --set "extension-argument:<I>{name=value}</I>"
071 * </PRE>
072 * where "<I>{extension-name}</I>" is the name to use for the HTTP servlet
073 * extension instance, "<I>{class-name}</I>" is the fully-qualified name of the
074 * Java class that extends
075 * {@code com.unboundid.directory.sdk.ds.api.HTTPServletExtension},
076 * and "<I>{name=value}</I>" represents name-value pairs for any arguments to
077 * provide to the HTTP servlet extension. If multiple arguments should be
078 * provided to the HTTP servlet extension, then the
079 * "<CODE>--set extension-argument:<I>{name=value}</I></CODE>" option should be
080 * provided multiple times.
081 * <BR><BR>
082 * Note that the server also provides the ability to run full web applications,
083 * by creating a Web Application Extension and specifying the necessary
084 * properties. If that web application needs to perform internal operations or
085 * interact with the server in any way, then the
086 * {@link com.unboundid.directory.sdk.http.types.WebAppServerContextFactory}
087 * class may be called from the web application in order to obtain a server
088 * context.
089 *
090 * @see com.unboundid.directory.sdk.http.scripting.ScriptedHTTPServletExtension
091 */
092 @Extensible()
093 @DirectoryServerExtension()
094 @DirectoryProxyServerExtension(appliesToLocalContent=true,
095 appliesToRemoteContent=true)
096 @MetricsEngineExtension()
097 @IdentityBrokerExtension()
098 @ThreadSafety(level=ThreadSafetyLevel.INTERFACE_THREADSAFE)
099 public abstract class HTTPServletExtension
100 implements UnboundIDExtension,
101 Reconfigurable<HTTPServletExtensionConfig>,
102 ExampleUsageProvider
103 {
104 /**
105 * Creates a new instance of this HTTP servlet extension. All HTTP servlet
106 * extension implementations must include a default constructor, but any
107 * initialization should generally be done in the
108 * {@code createServlet} method.
109 */
110 public HTTPServletExtension()
111 {
112 // No implementation is required.
113 }
114
115
116
117 /**
118 * {@inheritDoc}
119 */
120 public abstract String getExtensionName();
121
122
123
124 /**
125 * {@inheritDoc}
126 */
127 public abstract String[] getExtensionDescription();
128
129
130
131 /**
132 * {@inheritDoc}
133 */
134 public void defineConfigArguments(final ArgumentParser parser)
135 throws ArgumentException
136 {
137 // No arguments will be allowed by default.
138 }
139
140
141
142 /**
143 * {@inheritDoc}
144 */
145 public boolean isConfigurationAcceptable(
146 final HTTPServletExtensionConfig config,
147 final ArgumentParser parser,
148 final List<String> unacceptableReasons)
149 {
150 // No extended validation will be performed by default.
151 return true;
152 }
153
154
155
156 /**
157 * {@inheritDoc}
158 */
159 public ResultCode applyConfiguration(final HTTPServletExtensionConfig config,
160 final ArgumentParser parser,
161 final List<String> adminActionsRequired,
162 final List<String> messages)
163 {
164 // By default, no configuration changes will be applied. If there are any
165 // arguments, then add an admin action message indicating that the extension
166 // needs to be restarted for any changes to take effect.
167 if (! parser.getNamedArguments().isEmpty())
168 {
169 adminActionsRequired.add(
170 "No configuration change has actually been applied. The new " +
171 "configuration will not take effect until this HTTP servlet " +
172 "extension is disabled and re-enabled or until the server is " +
173 "restarted.");
174 }
175
176 return ResultCode.SUCCESS;
177 }
178
179
180
181 /**
182 * {@inheritDoc}
183 */
184 public Map<List<String>,String> getExamplesArgumentSets()
185 {
186 return Collections.emptyMap();
187 }
188
189
190
191 /**
192 * Creates an HTTP servlet extension using the provided information.
193 *
194 * @param serverContext A handle to the server context for the server in
195 * which this extension is running.
196 * @param config The general configuration for this HTTP servlet
197 * extension.
198 * @param parser The argument parser which has been initialized from
199 * the configuration for this HTTP servlet extension.
200 *
201 * @return The HTTP servlet that has been created.
202 *
203 * @throws LDAPException If a problem is encountered while attempting to
204 * create the HTTP servlet.
205 */
206 public abstract HttpServlet createServlet(
207 final HTTPServerContext serverContext,
208 final HTTPServletExtensionConfig config,
209 final ArgumentParser parser)
210 throws LDAPException;
211
212
213
214 /**
215 * Retrieves a list of the request paths for which the associated servlet
216 * should be invoked. This method will be called after the
217 * {@link #createServlet} method has been used to create the servlet instance.
218 *
219 * @return A list of the request paths for which the associated servlet
220 * should be invoked.
221 */
222 public abstract List<String> getServletPaths();
223
224
225
226 /**
227 * Retrieves a map of initialization parameters that should be provided to the
228 * servlet when it is initialized.
229 *
230 * @return A map of initialization parameters that should be provided to the
231 * servlet when it is initialized, or an empty map if no
232 * initialization parameters are needed.
233 */
234 public Map<String,String> getServletInitParameters()
235 {
236 return Collections.emptyMap();
237 }
238
239
240
241 /**
242 * Retrieves the order in which the servlet should be started. A value
243 * greater than or equal to zero guarantees that the servlet will be started
244 * as soon as the servlet engine has been started, in order of ascending
245 * servlet init order values, before the {@code doPostRegistrationProcessing}
246 * method has been called. If the value is less than zero, the servlet may
247 * not be started until a request is received for one of its registered paths.
248 *
249 * @return The order in which the servlet should be started, or a negative
250 * value if startup order does not matter.
251 */
252 public int getServletInitOrder()
253 {
254 return -1;
255 }
256
257
258
259 /**
260 * Retrieves a list of servlet filter instances that should be installed with
261 * the created servlet instance, in the order they should be invoked. If the
262 * servlet is to be registered with multiple paths, then these filters will be
263 * installed for all of those paths.
264 *
265 * @return A list of servlet filter instances that should be installed with
266 * the created servlet instance, in the order that they should be
267 * invoked. It may be {@code null} or empty if no servlet filters
268 * should be installed.
269 */
270 public List<Filter> getServletFilters()
271 {
272 return Collections.emptyList();
273 }
274
275
276
277 /**
278 * Performs any processing that may be needed after the servlet has been
279 * registered with the servlet engine. If the value returned from
280 * {@link #getServletInitOrder()} is greater than or equal to zero, then the
281 * servlet will have been started before this method is called. If the value
282 * returned from {@code getServletInitOrder()} is negative, then the servlet
283 * may or may not have been started by the time this method is called.
284 * <BR><BR>
285 * Note that the associated servlet can also perform any necessary
286 * initialization processing in the {@code init} method provided by the
287 * servlet API.
288 */
289 public void doPostRegistrationProcessing()
290 {
291 // No implementation required by default.
292 }
293
294
295
296 /**
297 * Performs any processing that may be needed after the servlet has been
298 * taken out of service and the associated servlet engine has been shut down.
299 * <BR><BR>
300 * Note that the associated servlet can also perform any necessary
301 * finalization processing in the {@code destroy} method provided by the
302 * servlet API. That method will be called after the servlet has been taken
303 * out of service, but before the servlet engine has been shut down.
304 */
305 public void doPostShutdownProcessing()
306 {
307 // No implementation required by default.
308 }
309 }