1 /*
2 * Copyright (c) 2002, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.management.remote;
27
28 import com.sun.jmx.mbeanserver.Util;
29 import java.io.IOException;
30 import java.net.MalformedURLException;
31 import java.util.Collections;
32 import java.util.HashMap;
33 import java.util.Map;
34 import java.util.Iterator;
35 import java.util.ServiceLoader;
36 import java.util.StringTokenizer;
37 import java.security.AccessController;
38 import java.security.PrivilegedAction;
39
40 import com.sun.jmx.remote.util.ClassLogger;
41 import com.sun.jmx.remote.util.EnvHelp;
42 import sun.reflect.misc.ReflectUtil;
43
44
45 /**
46 * <p>Factory to create JMX API connector clients. There
47 * are no instances of this class.</p>
48 *
49 * <p>Connections are usually made using the {@link
50 * #connect(JMXServiceURL) connect} method of this class. More
51 * advanced applications can separate the creation of the connector
52 * client, using {@link #newJMXConnector(JMXServiceURL, Map)
53 * newJMXConnector} and the establishment of the connection itself, using
54 * {@link JMXConnector#connect(Map)}.</p>
55 *
56 * <p>Each client is created by an instance of {@link
57 * JMXConnectorProvider}. This instance is found as follows. Suppose
58 * the given {@link JMXServiceURL} looks like
59 * <code>"service:jmx:<em>protocol</em>:<em>remainder</em>"</code>.
60 * Then the factory will attempt to find the appropriate {@link
61 * JMXConnectorProvider} for <code><em>protocol</em></code>. Each
62 * occurrence of the character <code>+</code> or <code>-</code> in
63 * <code><em>protocol</em></code> is replaced by <code>.</code> or
64 * <code>_</code>, respectively.</p>
65 *
66 * <p>A <em>provider package list</em> is searched for as follows:</p>
67 *
68 * <ol>
69 *
70 * <li>If the <code>environment</code> parameter to {@link
71 * #newJMXConnector(JMXServiceURL, Map) newJMXConnector} contains the
72 * key <code>jmx.remote.protocol.provider.pkgs</code> then the
73 * associated value is the provider package list.
74 *
75 * <li>Otherwise, if the system property
76 * <code>jmx.remote.protocol.provider.pkgs</code> exists, then its value
77 * is the provider package list.
78 *
79 * <li>Otherwise, there is no provider package list.
80 *
81 * </ol>
82 *
83 * <p>The provider package list is a string that is interpreted as a
84 * list of non-empty Java package names separated by vertical bars
85 * (<code>|</code>). If the string is empty, then so is the provider
86 * package list. If the provider package list is not a String, or if
87 * it contains an element that is an empty string, a {@link
88 * JMXProviderException} is thrown.</p>
89 *
90 * <p>If the provider package list exists and is not empty, then for
91 * each element <code><em>pkg</em></code> of the list, the factory
92 * will attempt to load the class
93 *
94 * <blockquote>
95 * <code><em>pkg</em>.<em>protocol</em>.ClientProvider</code>
96 * </blockquote>
97
98 * <p>If the <code>environment</code> parameter to {@link
99 * #newJMXConnector(JMXServiceURL, Map) newJMXConnector} contains the
100 * key <code>jmx.remote.protocol.provider.class.loader</code> then the
101 * associated value is the class loader to use to load the provider.
102 * If the associated value is not an instance of {@link
103 * java.lang.ClassLoader}, an {@link
104 * java.lang.IllegalArgumentException} is thrown.</p>
105 *
106 * <p>If the <code>jmx.remote.protocol.provider.class.loader</code>
107 * key is not present in the <code>environment</code> parameter, the
108 * calling thread's context class loader is used.</p>
109 *
110 * <p>If the attempt to load this class produces a {@link
111 * ClassNotFoundException}, the search for a handler continues with
112 * the next element of the list.</p>
113 *
114 * <p>Otherwise, a problem with the provider found is signalled by a
115 * {@link JMXProviderException} whose {@link
116 * JMXProviderException#getCause() <em>cause</em>} indicates the underlying
117 * exception, as follows:</p>
118 *
119 * <ul>
120 *
121 * <li>if the attempt to load the class produces an exception other
122 * than <code>ClassNotFoundException</code>, that is the
123 * <em>cause</em>;
124 *
125 * <li>if {@link Class#newInstance()} for the class produces an
126 * exception, that is the <em>cause</em>.
127 *
128 * </ul>
129 *
130 * <p>If no provider is found by the above steps, including the
131 * default case where there is no provider package list, then the
132 * implementation will use its own provider for
133 * <code><em>protocol</em></code>, or it will throw a
134 * <code>MalformedURLException</code> if there is none. An
135 * implementation may choose to find providers by other means. For
136 * example, it may support the <a
137 * href="{@docRoot}/../technotes/guides/jar/jar.html#Service%20Provider">
138 * JAR conventions for service providers</a>, where the service
139 * interface is <code>JMXConnectorProvider</code>.</p>
140 *
141 * <p>Every implementation must support the RMI connector protocol with
142 * the default RMI transport, specified with string <code>rmi</code>.
143 * </p>
144 *
145 * <p>Once a provider is found, the result of the
146 * <code>newJMXConnector</code> method is the result of calling {@link
147 * JMXConnectorProvider#newJMXConnector(JMXServiceURL,Map) newJMXConnector}
148 * on the provider.</p>
149 *
150 * <p>The <code>Map</code> parameter passed to the
151 * <code>JMXConnectorProvider</code> is a new read-only
152 * <code>Map</code> that contains all the entries that were in the
153 * <code>environment</code> parameter to {@link
154 * #newJMXConnector(JMXServiceURL,Map)
155 * JMXConnectorFactory.newJMXConnector}, if there was one.
156 * Additionally, if the
157 * <code>jmx.remote.protocol.provider.class.loader</code> key is not
158 * present in the <code>environment</code> parameter, it is added to
159 * the new read-only <code>Map</code>. The associated value is the
160 * calling thread's context class loader.</p>
161 *
162 * @since 1.5
163 */
164 public class JMXConnectorFactory {
165
166 /**
167 * <p>Name of the attribute that specifies the default class
168 * loader. This class loader is used to deserialize return values and
169 * exceptions from remote <code>MBeanServerConnection</code>
170 * calls. The value associated with this attribute is an instance
171 * of {@link ClassLoader}.</p>
172 */
173 public static final String DEFAULT_CLASS_LOADER =
174 "jmx.remote.default.class.loader";
175
176 /**
177 * <p>Name of the attribute that specifies the provider packages
178 * that are consulted when looking for the handler for a protocol.
179 * The value associated with this attribute is a string with
180 * package names separated by vertical bars (<code>|</code>).</p>
181 */
182 public static final String PROTOCOL_PROVIDER_PACKAGES =
183 "jmx.remote.protocol.provider.pkgs";
184
185 /**
186 * <p>Name of the attribute that specifies the class
187 * loader for loading protocol providers.
188 * The value associated with this attribute is an instance
189 * of {@link ClassLoader}.</p>
190 */
191 public static final String PROTOCOL_PROVIDER_CLASS_LOADER =
192 "jmx.remote.protocol.provider.class.loader";
193
194 private static final String PROTOCOL_PROVIDER_DEFAULT_PACKAGE =
195 "com.sun.jmx.remote.protocol";
196
197 private static final ClassLogger logger =
198 new ClassLogger("javax.management.remote.misc", "JMXConnectorFactory");
199
200 /** There are no instances of this class. */
201 private JMXConnectorFactory() {
202 }
203
204 /**
205 * <p>Creates a connection to the connector server at the given
206 * address.</p>
207 *
208 * <p>This method is equivalent to {@link
209 * #connect(JMXServiceURL,Map) connect(serviceURL, null)}.</p>
210 *
211 * @param serviceURL the address of the connector server to
212 * connect to.
213 *
214 * @return a <code>JMXConnector</code> whose {@link
215 * JMXConnector#connect connect} method has been called.
216 *
217 * @exception NullPointerException if <code>serviceURL</code> is null.
218 *
219 * @exception IOException if the connector client or the
220 * connection cannot be made because of a communication problem.
221 *
222 * @exception SecurityException if the connection cannot be made
223 * for security reasons.
224 */
225 public static JMXConnector connect(JMXServiceURL serviceURL)
226 throws IOException {
227 return connect(serviceURL, null);
228 }
229
230 /**
231 * <p>Creates a connection to the connector server at the given
232 * address.</p>
233 *
234 * <p>This method is equivalent to:</p>
235 *
236 * <pre>
237 * JMXConnector conn = JMXConnectorFactory.newJMXConnector(serviceURL,
238 * environment);
239 * conn.connect(environment);
240 * </pre>
241 *
242 * @param serviceURL the address of the connector server to connect to.
243 *
244 * @param environment a set of attributes to determine how the
245 * connection is made. This parameter can be null. Keys in this
246 * map must be Strings. The appropriate type of each associated
247 * value depends on the attribute. The contents of
248 * <code>environment</code> are not changed by this call.
249 *
250 * @return a <code>JMXConnector</code> representing the newly-made
251 * connection. Each successful call to this method produces a
252 * different object.
253 *
254 * @exception NullPointerException if <code>serviceURL</code> is null.
255 *
256 * @exception IOException if the connector client or the
257 * connection cannot be made because of a communication problem.
258 *
259 * @exception SecurityException if the connection cannot be made
260 * for security reasons.
261 */
262 public static JMXConnector connect(JMXServiceURL serviceURL,
263 Map<String,?> environment)
264 throws IOException {
265 if (serviceURL == null)
266 throw new NullPointerException("Null JMXServiceURL");
267 JMXConnector conn = newJMXConnector(serviceURL, environment);
268 conn.connect(environment);
269 return conn;
270 }
271
272 private static <K,V> Map<K,V> newHashMap() {
273 return new HashMap<K,V>();
274 }
275
276 private static <K> Map<K,Object> newHashMap(Map<K,?> map) {
277 return new HashMap<K,Object>(map);
278 }
279
280 /**
281 * <p>Creates a connector client for the connector server at the
282 * given address. The resultant client is not connected until its
283 * {@link JMXConnector#connect(Map) connect} method is called.</p>
284 *
285 * @param serviceURL the address of the connector server to connect to.
286 *
287 * @param environment a set of attributes to determine how the
288 * connection is made. This parameter can be null. Keys in this
289 * map must be Strings. The appropriate type of each associated
290 * value depends on the attribute. The contents of
291 * <code>environment</code> are not changed by this call.
292 *
293 * @return a <code>JMXConnector</code> representing the new
294 * connector client. Each successful call to this method produces
295 * a different object.
296 *
297 * @exception NullPointerException if <code>serviceURL</code> is null.
298 *
299 * @exception IOException if the connector client cannot be made
300 * because of a communication problem.
301 *
302 * @exception MalformedURLException if there is no provider for the
303 * protocol in <code>serviceURL</code>.
304 *
305 * @exception JMXProviderException if there is a provider for the
306 * protocol in <code>serviceURL</code> but it cannot be used for
307 * some reason.
308 */
309 public static JMXConnector newJMXConnector(JMXServiceURL serviceURL,
310 Map<String,?> environment)
311 throws IOException {
312
313 final Map<String,Object> envcopy;
314 if (environment == null)
315 envcopy = newHashMap();
316 else {
317 EnvHelp.checkAttributes(environment);
318 envcopy = newHashMap(environment);
319 }
320
321 final ClassLoader loader = resolveClassLoader(envcopy);
322 final Class<JMXConnectorProvider> targetInterface =
323 JMXConnectorProvider.class;
324 final String protocol = serviceURL.getProtocol();
325 final String providerClassName = "ClientProvider";
326 final JMXServiceURL providerURL = serviceURL;
327
328 JMXConnectorProvider provider = getProvider(providerURL, envcopy,
329 providerClassName,
330 targetInterface,
331 loader);
332
333 IOException exception = null;
334 if (provider == null) {
335 // Loader is null when context class loader is set to null
336 // and no loader has been provided in map.
337 // com.sun.jmx.remote.util.Service class extracted from j2se
338 // provider search algorithm doesn't handle well null classloader.
339 if (loader != null) {
340 try {
341 JMXConnector connection =
342 getConnectorAsService(loader, providerURL, envcopy);
343 if (connection != null)
344 return connection;
345 } catch (JMXProviderException e) {
346 throw e;
347 } catch (IOException e) {
348 exception = e;
349 }
350 }
351 provider = getProvider(protocol, PROTOCOL_PROVIDER_DEFAULT_PACKAGE,
352 JMXConnectorFactory.class.getClassLoader(),
353 providerClassName, targetInterface);
354 }
355
356 if (provider == null) {
357 MalformedURLException e =
358 new MalformedURLException("Unsupported protocol: " + protocol);
359 if (exception == null) {
360 throw e;
361 } else {
362 throw EnvHelp.initCause(e, exception);
363 }
364 }
365
366 final Map<String,Object> fixedenv =
367 Collections.unmodifiableMap(envcopy);
368
369 return provider.newJMXConnector(serviceURL, fixedenv);
370 }
371
372 private static String resolvePkgs(Map<String, ?> env)
373 throws JMXProviderException {
374
375 Object pkgsObject = null;
376
377 if (env != null)
378 pkgsObject = env.get(PROTOCOL_PROVIDER_PACKAGES);
379
380 if (pkgsObject == null)
381 pkgsObject =
382 AccessController.doPrivileged(new PrivilegedAction<String>() {
383 public String run() {
384 return System.getProperty(PROTOCOL_PROVIDER_PACKAGES);
385 }
386 });
387
388 if (pkgsObject == null)
389 return null;
390
391 if (!(pkgsObject instanceof String)) {
392 final String msg = "Value of " + PROTOCOL_PROVIDER_PACKAGES +
393 " parameter is not a String: " +
394 pkgsObject.getClass().getName();
395 throw new JMXProviderException(msg);
396 }
397
398 final String pkgs = (String) pkgsObject;
399 if (pkgs.trim().equals(""))
400 return null;
401
402 // pkgs may not contain an empty element
403 if (pkgs.startsWith("|") || pkgs.endsWith("|") ||
404 pkgs.indexOf("||") >= 0) {
405 final String msg = "Value of " + PROTOCOL_PROVIDER_PACKAGES +
406 " contains an empty element: " + pkgs;
407 throw new JMXProviderException(msg);
408 }
409
410 return pkgs;
411 }
412
413 static <T> T getProvider(JMXServiceURL serviceURL,
414 final Map<String, Object> environment,
415 String providerClassName,
416 Class<T> targetInterface,
417 final ClassLoader loader)
418 throws IOException {
419
420 final String protocol = serviceURL.getProtocol();
421
422 final String pkgs = resolvePkgs(environment);
423
424 T instance = null;
425
426 if (pkgs != null) {
427 instance =
428 getProvider(protocol, pkgs, loader, providerClassName,
429 targetInterface);
430
431 if (instance != null) {
432 boolean needsWrap = (loader != instance.getClass().getClassLoader());
433 environment.put(PROTOCOL_PROVIDER_CLASS_LOADER, needsWrap ? wrap(loader) : loader);
434 }
435 }
436
437 return instance;
438 }
439
440 static <T> Iterator<T> getProviderIterator(final Class<T> providerClass,
441 final ClassLoader loader) {
442 ServiceLoader<T> serviceLoader =
443 ServiceLoader.load(providerClass, loader);
444 return serviceLoader.iterator();
445 }
446
447 private static ClassLoader wrap(final ClassLoader parent) {
448 return parent != null ? AccessController.doPrivileged(new PrivilegedAction<ClassLoader>() {
449 @Override
450 public ClassLoader run() {
451 return new ClassLoader(parent) {
452 @Override
453 protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
454 ReflectUtil.checkPackageAccess(name);
455 return super.loadClass(name, resolve);
456 }
457 };
458 }
459 }) : null;
460 }
461
462 private static JMXConnector getConnectorAsService(ClassLoader loader,
463 JMXServiceURL url,
464 Map<String, ?> map)
465 throws IOException {
466
467 Iterator<JMXConnectorProvider> providers =
468 getProviderIterator(JMXConnectorProvider.class, loader);
469 JMXConnector connection;
470 IOException exception = null;
471 while (providers.hasNext()) {
472 JMXConnectorProvider provider = providers.next();
473 try {
474 connection = provider.newJMXConnector(url, map);
475 return connection;
476 } catch (JMXProviderException e) {
477 throw e;
478 } catch (Exception e) {
479 if (logger.traceOn())
480 logger.trace("getConnectorAsService",
481 "URL[" + url +
482 "] Service provider exception: " + e);
483 if (!(e instanceof MalformedURLException)) {
484 if (exception == null) {
485 if (e instanceof IOException) {
486 exception = (IOException) e;
487 } else {
488 exception = EnvHelp.initCause(
489 new IOException(e.getMessage()), e);
490 }
491 }
492 }
493 continue;
494 }
495 }
496 if (exception == null)
497 return null;
498 else
499 throw exception;
500 }
501
502 static <T> T getProvider(String protocol,
503 String pkgs,
504 ClassLoader loader,
505 String providerClassName,
506 Class<T> targetInterface)
507 throws IOException {
508
509 StringTokenizer tokenizer = new StringTokenizer(pkgs, "|");
510
511 while (tokenizer.hasMoreTokens()) {
512 String pkg = tokenizer.nextToken();
513 String className = (pkg + "." + protocol2package(protocol) +
514 "." + providerClassName);
515 Class<?> providerClass;
516 try {
517 providerClass = Class.forName(className, true, loader);
518 } catch (ClassNotFoundException e) {
519 //Add trace.
520 continue;
521 }
522
523 if (!targetInterface.isAssignableFrom(providerClass)) {
524 final String msg =
525 "Provider class does not implement " +
526 targetInterface.getName() + ": " +
527 providerClass.getName();
528 throw new JMXProviderException(msg);
529 }
530
531 // We have just proved that this cast is correct
532 Class<? extends T> providerClassT = Util.cast(providerClass);
533 try {
534 @SuppressWarnings("deprecation")
535 T result = providerClassT.newInstance();
536 return result;
537 } catch (Exception e) {
538 final String msg =
539 "Exception when instantiating provider [" + className +
540 "]";
541 throw new JMXProviderException(msg, e);
542 }
543 }
544
545 return null;
546 }
547
548 static ClassLoader resolveClassLoader(Map<String, ?> environment) {
549 ClassLoader loader = null;
550
551 if (environment != null) {
552 try {
553 loader = (ClassLoader)
554 environment.get(PROTOCOL_PROVIDER_CLASS_LOADER);
555 } catch (ClassCastException e) {
556 final String msg =
557 "The ClassLoader supplied in the environment map using " +
558 "the " + PROTOCOL_PROVIDER_CLASS_LOADER +
559 " attribute is not an instance of java.lang.ClassLoader";
560 throw new IllegalArgumentException(msg);
561 }
562 }
563
564 if (loader == null) {
565 loader = Thread.currentThread().getContextClassLoader();
566 }
567
568 return loader;
569 }
570
571 private static String protocol2package(String protocol) {
572 return protocol.replace('+', '.').replace('-', '_');
573 }
574 }