/*
* Copyright (c) 2002, 2007, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package javax.management.remote;
import com.sun.jmx.mbeanserver.Util;
import java.io.IOException;
import java.net.MalformedURLException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Iterator;
import java.util.ServiceLoader;
import java.util.StringTokenizer;
import java.security.AccessController;
import java.security.PrivilegedAction;
import com.sun.jmx.remote.util.ClassLogger;
import com.sun.jmx.remote.util.EnvHelp;
/**
* <p>Factory to create JMX API connector clients. There
* are no instances of this class.</p>
*
* <p>Connections are usually made using the {@link
* #connect(JMXServiceURL) connect} method of this class. More
* advanced applications can separate the creation of the connector
* client, using {@link #newJMXConnector(JMXServiceURL, Map)
* newJMXConnector} and the establishment of the connection itself, using
* {@link JMXConnector#connect(Map)}.</p>
*
* <p>Each client is created by an instance of {@link
* JMXConnectorProvider}. This instance is found as follows. Suppose
* the given {@link JMXServiceURL} looks like
* <code>"service:jmx:<em>protocol</em>:<em>remainder</em>"</code>.
* Then the factory will attempt to find the appropriate {@link
* JMXConnectorProvider} for <code><em>protocol</em></code>. Each
* occurrence of the character <code>+</code> or <code>-</code> in
* <code><em>protocol</em></code> is replaced by <code>.</code> or
* <code>_</code>, respectively.</p>
*
* <p>A <em>provider package list</em> is searched for as follows:</p>
*
* <ol>
*
* <li>If the <code>environment</code> parameter to {@link
* #newJMXConnector(JMXServiceURL, Map) newJMXConnector} contains the
* key <code>jmx.remote.protocol.provider.pkgs</code> then the
* associated value is the provider package list.
*
* <li>Otherwise, if the system property
* <code>jmx.remote.protocol.provider.pkgs</code> exists, then its value
* is the provider package list.
*
* <li>Otherwise, there is no provider package list.
*
* </ol>
*
* <p>The provider package list is a string that is interpreted as a
* list of non-empty Java package names separated by vertical bars
* (<code>|</code>). If the string is empty, then so is the provider
* package list. If the provider package list is not a String, or if
* it contains an element that is an empty string, a {@link
* JMXProviderException} is thrown.</p>
*
* <p>If the provider package list exists and is not empty, then for
* each element <code><em>pkg</em></code> of the list, the factory
* will attempt to load the class
*
* <blockquote>
* <code><em>pkg</em>.<em>protocol</em>.ClientProvider</code>
* </blockquote>
* <p>If the <code>environment</code> parameter to {@link
* #newJMXConnector(JMXServiceURL, Map) newJMXConnector} contains the
* key <code>jmx.remote.protocol.provider.class.loader</code> then the
* associated value is the class loader to use to load the provider.
* If the associated value is not an instance of {@link
* java.lang.ClassLoader}, an {@link
* java.lang.IllegalArgumentException} is thrown.</p>
*
* <p>If the <code>jmx.remote.protocol.provider.class.loader</code>
* key is not present in the <code>environment</code> parameter, the
* calling thread's context class loader is used.</p>
*
* <p>If the attempt to load this class produces a {@link
* ClassNotFoundException}, the search for a handler continues with
* the next element of the list.</p>
*
* <p>Otherwise, a problem with the provider found is signalled by a
* {@link JMXProviderException} whose {@link
* JMXProviderException#getCause() <em>cause</em>} indicates the underlying
* exception, as follows:</p>
*
* <ul>
*
* <li>if the attempt to load the class produces an exception other
* than <code>ClassNotFoundException</code>, that is the
* <em>cause</em>;
*
* <li>if {@link Class#newInstance()} for the class produces an
* exception, that is the <em>cause</em>.
*
* </ul>
*
* <p>If no provider is found by the above steps, including the
* default case where there is no provider package list, then the
* implementation will use its own provider for
* <code><em>protocol</em></code>, or it will throw a
* <code>MalformedURLException</code> if there is none. An
* implementation may choose to find providers by other means. For
* example, it may support the <a
* href="{@docRoot}/../technotes/guides/jar/jar.html#Service Provider">
* JAR conventions for service providers</a>, where the service
* interface is <code>JMXConnectorProvider</code>.</p>
*
* <p>Every implementation must support the RMI connector protocols,
* specified with the string <code>rmi</code> or
* <code>iiop</code>.</p>
*
* <p>Once a provider is found, the result of the
* <code>newJMXConnector</code> method is the result of calling {@link
* JMXConnectorProvider#newJMXConnector(JMXServiceURL,Map) newJMXConnector}
* on the provider.</p>
*
* <p>The <code>Map</code> parameter passed to the
* <code>JMXConnectorProvider</code> is a new read-only
* <code>Map</code> that contains all the entries that were in the
* <code>environment</code> parameter to {@link
* #newJMXConnector(JMXServiceURL,Map)
* JMXConnectorFactory.newJMXConnector}, if there was one.
* Additionally, if the
* <code>jmx.remote.protocol.provider.class.loader</code> key is not
* present in the <code>environment</code> parameter, it is added to
* the new read-only <code>Map</code>. The associated value is the
* calling thread's context class loader.</p>
*
* @since 1.5
*/
public class JMXConnectorFactory {
/**
* <p>Name of the attribute that specifies the default class
* loader. This class loader is used to deserialize return values and
* exceptions from remote <code>MBeanServerConnection</code>
* calls. The value associated with this attribute is an instance
* of {@link ClassLoader}.</p>
*/
public static final String DEFAULT_CLASS_LOADER =
"jmx.remote.default.class.loader";
/**
* <p>Name of the attribute that specifies the provider packages
* that are consulted when looking for the handler for a protocol.
* The value associated with this attribute is a string with
* package names separated by vertical bars (<code>|</code>).</p>
*/
public static final String PROTOCOL_PROVIDER_PACKAGES =
"jmx.remote.protocol.provider.pkgs";
/**
* <p>Name of the attribute that specifies the class
* loader for loading protocol providers.
* The value associated with this attribute is an instance
* of {@link ClassLoader}.</p>
*/
public static final String PROTOCOL_PROVIDER_CLASS_LOADER =
"jmx.remote.protocol.provider.class.loader";
private static final String PROTOCOL_PROVIDER_DEFAULT_PACKAGE =
"com.sun.jmx.remote.protocol";
private static final ClassLogger logger =
new ClassLogger("javax.management.remote.misc", "JMXConnectorFactory");
/** There are no instances of this class. */
private JMXConnectorFactory() {
}
/**
* <p>Creates a connection to the connector server at the given
* address.</p>
*
* <p>This method is equivalent to {@link
* #connect(JMXServiceURL,Map) connect(serviceURL, null)}.</p>
*
* @param serviceURL the address of the connector server to
* connect to.
*
* @return a <code>JMXConnector</code> whose {@link
* JMXConnector#connect connect} method has been called.
*
* @exception NullPointerException if <code>serviceURL</code> is null.
*
* @exception IOException if the connector client or the
* connection cannot be made because of a communication problem.
*
* @exception SecurityException if the connection cannot be made
* for security reasons.
*/
public static JMXConnector connect(JMXServiceURL serviceURL)
throws IOException {
return connect(serviceURL, null);
}
/**
* <p>Creates a connection to the connector server at the given
* address.</p>
*
* <p>This method is equivalent to:</p>
*
* <pre>
* JMXConnector conn = JMXConnectorFactory.newJMXConnector(serviceURL,
* environment);
* conn.connect(environment);
* </pre>
*
* @param serviceURL the address of the connector server to connect to.
*
* @param environment a set of attributes to determine how the
* connection is made. This parameter can be null. Keys in this
* map must be Strings. The appropriate type of each associated
* value depends on the attribute. The contents of
* <code>environment</code> are not changed by this call.
*
* @return a <code>JMXConnector</code> representing the newly-made
* connection. Each successful call to this method produces a
* different object.
*
* @exception NullPointerException if <code>serviceURL</code> is null.
*
* @exception IOException if the connector client or the
* connection cannot be made because of a communication problem.
*
* @exception SecurityException if the connection cannot be made
* for security reasons.
*/
public static JMXConnector connect(JMXServiceURL serviceURL,
Map<String,?> environment)
throws IOException {
if (serviceURL == null)
throw new NullPointerException("Null JMXServiceURL");
JMXConnector conn = newJMXConnector(serviceURL, environment);
conn.connect(environment);
return conn;
}
/**
* <p>Creates a connector client for the connector server at the
* given address. The resultant client is not connected until its
* {@link JMXConnector#connect(Map) connect} method is called.</p>
*
* @param serviceURL the address of the connector server to connect to.
*
* @param environment a set of attributes to determine how the
* connection is made. This parameter can be null. Keys in this
* map must be Strings. The appropriate type of each associated
* value depends on the attribute. The contents of
* <code>environment</code> are not changed by this call.
*
* @return a <code>JMXConnector</code> representing the new
* connector client. Each successful call to this method produces
* a different object.
*
* @exception NullPointerException if <code>serviceURL</code> is null.
*
* @exception IOException if the connector client cannot be made
* because of a communication problem.
*
* @exception MalformedURLException if there is no provider for the
* protocol in <code>serviceURL</code>.
*
* @exception JMXProviderException if there is a provider for the
* protocol in <code>serviceURL</code> but it cannot be used for
* some reason.
*/
public static JMXConnector newJMXConnector(JMXServiceURL serviceURL,
Map<String,?> environment)
throws IOException {
Map<String, Object> envcopy;
if (environment == null)
envcopy = new HashMap<String, Object>();
else {
EnvHelp.checkAttributes(environment);
envcopy = new HashMap<String, Object>(environment);
}
final ClassLoader loader = resolveClassLoader(envcopy);
final Class<JMXConnectorProvider> targetInterface = JMXConnectorProvider.class;
final String protocol = serviceURL.getProtocol();
final String providerClassName = "ClientProvider";
JMXConnectorProvider provider =
getProvider(serviceURL, envcopy, providerClassName,
targetInterface, loader);
IOException exception = null;
if (provider == null) {
// Loader is null when context class loader is set to null
// and no loader has been provided in map.
// com.sun.jmx.remote.util.Service class extracted from j2se
// provider search algorithm doesn't handle well null classloader.
if (loader != null) {
try {
JMXConnector connection =
getConnectorAsService(loader, serviceURL, envcopy);
if (connection != null)
return connection;
} catch (JMXProviderException e) {
throw e;
} catch (IOException e) {
exception = e;
}
}
provider =
getProvider(protocol, PROTOCOL_PROVIDER_DEFAULT_PACKAGE,
JMXConnectorFactory.class.getClassLoader(),
providerClassName, targetInterface);
}
if (provider == null) {
MalformedURLException e =
new MalformedURLException("Unsupported protocol: " + protocol);
if (exception == null) {
throw e;
} else {
throw EnvHelp.initCause(e, exception);
}
}
envcopy = Collections.unmodifiableMap(envcopy);
return provider.newJMXConnector(serviceURL, envcopy);
}
private static String resolvePkgs(Map env) throws JMXProviderException {
Object pkgsObject = null;
if (env != null)
pkgsObject = env.get(PROTOCOL_PROVIDER_PACKAGES);
if (pkgsObject == null)
pkgsObject =
AccessController.doPrivileged(new PrivilegedAction<Object>() {
public Object run() {
return System.getProperty(PROTOCOL_PROVIDER_PACKAGES);
}
});
if (pkgsObject == null)
return null;
if (!(pkgsObject instanceof String)) {
final String msg = "Value of " + PROTOCOL_PROVIDER_PACKAGES +
" parameter is not a String: " +
pkgsObject.getClass().getName();
throw new JMXProviderException(msg);
}
final String pkgs = (String) pkgsObject;
if (pkgs.trim().equals(""))
return null;
// pkgs may not contain an empty element
if (pkgs.startsWith("|") || pkgs.endsWith("|") ||
pkgs.indexOf("||") >= 0) {
final String msg = "Value of " + PROTOCOL_PROVIDER_PACKAGES +
" contains an empty element: " + pkgs;
throw new JMXProviderException(msg);
}
return pkgs;
}
static <T> T getProvider(JMXServiceURL serviceURL,
Map<String, Object> environment,
String providerClassName,
Class<T> targetInterface,
ClassLoader loader)
throws IOException {
final String protocol = serviceURL.getProtocol();
final String pkgs = resolvePkgs(environment);
T instance = null;
if (pkgs != null) {
environment.put(PROTOCOL_PROVIDER_CLASS_LOADER, loader);
instance =
getProvider(protocol, pkgs, loader, providerClassName,
targetInterface);
}
return instance;
}
static <T> Iterator<T> getProviderIterator(final Class<T> providerClass,
final ClassLoader loader) {
ServiceLoader<T> serviceLoader =
ServiceLoader.load(providerClass,
loader);
return serviceLoader.iterator();
}
private static JMXConnector getConnectorAsService(ClassLoader loader,
JMXServiceURL url,
Map<String, ?> map)
throws IOException {
Iterator<JMXConnectorProvider> providers =
getProviderIterator(JMXConnectorProvider.class, loader);
JMXConnector connection = null;
IOException exception = null;
while(providers.hasNext()) {
try {
connection = providers.next().newJMXConnector(url, map);
return connection;
} catch (JMXProviderException e) {
throw e;
} catch (Exception e) {
if (logger.traceOn())
logger.trace("getConnectorAsService",
"URL[" + url +
"] Service provider exception: " + e);
if (!(e instanceof MalformedURLException)) {
if (exception == null) {
if (exception instanceof IOException) {
exception = (IOException) e;
} else {
exception = EnvHelp.initCause(
new IOException(e.getMessage()), e);
}
}
}
continue;
}
}
if (exception == null)
return null;
else
throw exception;
}
static <T> T getProvider(String protocol,
String pkgs,
ClassLoader loader,
String providerClassName,
Class<T> targetInterface)
throws IOException {
StringTokenizer tokenizer = new StringTokenizer(pkgs, "|");
while (tokenizer.hasMoreTokens()) {
String pkg = tokenizer.nextToken();
String className = (pkg + "." + protocol2package(protocol) +
"." + providerClassName);
Class<?> providerClass;
try {
providerClass = Class.forName(className, true, loader);
} catch (ClassNotFoundException e) {
//Add trace.
continue;
}
if (!targetInterface.isAssignableFrom(providerClass)) {
final String msg =
"Provider class does not implement " +
targetInterface.getName() + ": " +
providerClass.getName();
throw new JMXProviderException(msg);
}
// We have just proved that this cast is correct
Class<? extends T> providerClassT = Util.cast(providerClass);
try {
return providerClassT.newInstance();
} catch (Exception e) {
final String msg =
"Exception when instantiating provider [" + className +
"]";
throw new JMXProviderException(msg, e);
}
}
return null;
}
static ClassLoader resolveClassLoader(Map environment) {
ClassLoader loader = null;
if (environment != null) {
try {
loader = (ClassLoader)
environment.get(PROTOCOL_PROVIDER_CLASS_LOADER);
} catch (ClassCastException e) {
final String msg =
"The ClassLoader supplied in the environment map using " +
"the " + PROTOCOL_PROVIDER_CLASS_LOADER +
" attribute is not an instance of java.lang.ClassLoader";
throw new IllegalArgumentException(msg);
}
}
if (loader == null)
loader =
AccessController.doPrivileged(new PrivilegedAction<ClassLoader>() {
public ClassLoader run() {
return
Thread.currentThread().getContextClassLoader();
}
});
return loader;
}
private static String protocol2package(String protocol) {
return protocol.replace('+', '.').replace('-', '_');
}
}