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 2011-2014 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 "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 @IdentityBrokerExtension()
097 @ThreadSafety(level=ThreadSafetyLevel.INTERFACE_THREADSAFE)
098 public abstract class HTTPServletExtension
099 implements UnboundIDExtension,
100 Reconfigurable<HTTPServletExtensionConfig>,
101 ExampleUsageProvider
102 {
103 /**
104 * Creates a new instance of this HTTP servlet extension. All HTTP servlet
105 * extension implementations must include a default constructor, but any
106 * initialization should generally be done in the
107 * {@code createServlet} method.
108 */
109 public HTTPServletExtension()
110 {
111 // No implementation is required.
112 }
113
114
115
116 /**
117 * {@inheritDoc}
118 */
119 public abstract String getExtensionName();
120
121
122
123 /**
124 * {@inheritDoc}
125 */
126 public abstract String[] getExtensionDescription();
127
128
129
130 /**
131 * {@inheritDoc}
132 */
133 public void defineConfigArguments(final ArgumentParser parser)
134 throws ArgumentException
135 {
136 // No arguments will be allowed by default.
137 }
138
139
140
141 /**
142 * {@inheritDoc}
143 */
144 public boolean isConfigurationAcceptable(
145 final HTTPServletExtensionConfig config,
146 final ArgumentParser parser,
147 final List<String> unacceptableReasons)
148 {
149 // No extended validation will be performed by default.
150 return true;
151 }
152
153
154
155 /**
156 * {@inheritDoc}
157 */
158 public ResultCode applyConfiguration(final HTTPServletExtensionConfig config,
159 final ArgumentParser parser,
160 final List<String> adminActionsRequired,
161 final List<String> messages)
162 {
163 // By default, no configuration changes will be applied. If there are any
164 // arguments, then add an admin action message indicating that the extension
165 // needs to be restarted for any changes to take effect.
166 if (! parser.getNamedArguments().isEmpty())
167 {
168 adminActionsRequired.add(
169 "No configuration change has actually been applied. The new " +
170 "configuration will not take effect until this HTTP servlet " +
171 "extension is disabled and re-enabled or until the server is " +
172 "restarted.");
173 }
174
175 return ResultCode.SUCCESS;
176 }
177
178
179
180 /**
181 * {@inheritDoc}
182 */
183 public Map<List<String>,String> getExamplesArgumentSets()
184 {
185 return Collections.emptyMap();
186 }
187
188
189
190 /**
191 * Creates an HTTP servlet extension using the provided information.
192 *
193 * @param serverContext A handle to the server context for the server in
194 * which this extension is running.
195 * @param config The general configuration for this HTTP servlet
196 * extension.
197 * @param parser The argument parser which has been initialized from
198 * the configuration for this HTTP servlet extension.
199 *
200 * @return The HTTP servlet that has been created.
201 *
202 * @throws LDAPException If a problem is encountered while attempting to
203 * create the HTTP servlet.
204 */
205 public abstract HttpServlet createServlet(
206 final HTTPServerContext serverContext,
207 final HTTPServletExtensionConfig config,
208 final ArgumentParser parser)
209 throws LDAPException;
210
211
212
213 /**
214 * Retrieves a list of the request paths for which the associated servlet
215 * should be invoked. This method will be called after the
216 * {@link #createServlet} method has been used to create the servlet instance.
217 *
218 * @return A list of the request paths for which the associated servlet
219 * should be invoked.
220 */
221 public abstract List<String> getServletPaths();
222
223
224
225 /**
226 * Retrieves a map of initialization parameters that should be provided to the
227 * servlet when it is initialized.
228 *
229 * @return A map of initialization parameters that should be provided to the
230 * servlet when it is initialized, or an empty map if no
231 * initialization parameters are needed.
232 */
233 public Map<String,String> getServletInitParameters()
234 {
235 return Collections.emptyMap();
236 }
237
238
239
240 /**
241 * Retrieves the order in which the servlet should be started. A value
242 * greater than or equal to zero guarantees that the servlet will be started
243 * as soon as the servlet engine has been started, in order of ascending
244 * servlet init order values, before the {@code doPostRegistrationProcessing}
245 * method has been called. If the value is less than zero, the servlet may
246 * not be started until a request is received for one of its registered paths.
247 *
248 * @return The order in which the servlet should be started, or a negative
249 * value if startup order does not matter.
250 */
251 public int getServletInitOrder()
252 {
253 return -1;
254 }
255
256
257
258 /**
259 * Retrieves a list of servlet filter instances that should be installed with
260 * the created servlet instance, in the order they should be invoked. If the
261 * servlet is to be registered with multiple paths, then these filters will be
262 * installed for all of those paths.
263 *
264 * @return A list of servlet filter instances that should be installed with
265 * the created servlet instance, in the order that they should be
266 * invoked. It may be {@code null} or empty if no servlet filters
267 * should be installed.
268 */
269 public List<Filter> getServletFilters()
270 {
271 return Collections.emptyList();
272 }
273
274
275
276 /**
277 * Performs any processing that may be needed after the servlet has been
278 * registered with the servlet engine. If the value returned from
279 * {@link #getServletInitOrder()} is greater than or equal to zero, then the
280 * servlet will have been started before this method is called. If the value
281 * returned from {@code getServletInitOrder()} is negative, then the servlet
282 * may or may not have been started by the time this method is called.
283 * <BR><BR>
284 * Note that the associated servlet can also perform any necessary
285 * initialization processing in the {@code init} method provided by the
286 * servlet API.
287 */
288 public void doPostRegistrationProcessing()
289 {
290 // No implementation required by default.
291 }
292
293
294
295 /**
296 * Performs any processing that may be needed after the servlet has been
297 * taken out of service and the associated servlet engine has been shut down.
298 * <BR><BR>
299 * Note that the associated servlet can also perform any necessary
300 * finalization processing in the {@code destroy} method provided by the
301 * servlet API. That method will be called after the servlet has been taken
302 * out of service, but before the servlet engine has been shut down.
303 */
304 public void doPostShutdownProcessing()
305 {
306 // No implementation required by default.
307 }
308 }