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