/*
* @(#)MBeanServerFactory.java 1.61 05/11/17
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package javax.management;
import com.sun.jmx.defaults.JmxProperties;
import com.sun.jmx.interceptor.DefaultMBeanServerInterceptor;
import com.sun.jmx.mbeanserver.GetPropertyAction;
import com.sun.jmx.trace.Trace;
import java.security.AccessController;
import java.security.Permission;
import java.util.ArrayList;
import javax.management.loading.ClassLoaderRepository;
/**
* <p>Provides MBean server references. There are no instances of
* this class.</p>
*
* <p>Since JMX 1.2 this class makes it possible to replace the default
* MBeanServer implementation. This is done using the
* {@link javax.management.MBeanServerBuilder} class.
* The class of the initial MBeanServerBuilder to be
* instantiated can be specified through the
* <b>javax.management.builder.initial</b> system property.
* The specified class must be a public subclass of
* {@link javax.management.MBeanServerBuilder}, and must have a public
* empty constructor.
* <p>By default, if no value for that property is specified, an instance of
* {@link
* javax.management.MBeanServerBuilder javax.management.MBeanServerBuilder}
* is created. Otherwise, the MBeanServerFactory attempts to load the
* specified class using
* {@link java.lang.Thread#getContextClassLoader()
* Thread.currentThread().getContextClassLoader()}, or if that is null,
* {@link java.lang.Class#forName(java.lang.String) Class.forName()}. Then
* it creates an initial instance of that Class using
* {@link java.lang.Class#newInstance()}. If any checked exception
* is raised during this process (e.g.
* {@link java.lang.ClassNotFoundException},
* {@link java.lang.InstantiationException}) the MBeanServerFactory
* will propagate this exception from within a RuntimeException.</p>
*
* <p>The <b>javax.management.builder.initial</b> system property is
* consulted every time a new MBeanServer needs to be created, and the
* class pointed to by that property is loaded. If that class is different
* from that of the current MBeanServerBuilder, then a new MBeanServerBuilder
* is created. Otherwise, the MBeanServerFactory may create a new
* MBeanServerBuilder or reuse the current one.</p>
*
* <p>If the class pointed to by the property cannot be
* loaded, or does not correspond to a valid subclass of MBeanServerBuilder
* then an exception is propagated, and no MBeanServer can be created until
* the <b>javax.management.builder.initial</b> system property is reset to
* valid value.</p>
*
* <p>The MBeanServerBuilder makes it possible to wrap the MBeanServers
* returned by the default MBeanServerBuilder implementation, for the purpose
* of e.g. adding an additional security layer.</p>
*
* @since 1.5
*/
public class MBeanServerFactory {
/*
* There are no instances of this class so don't generate the
* default public constructor.
*/
private MBeanServerFactory() {
}
/**
* The builder that will be used to construct MBeanServers.
*
* @since.unbundled JMX 1.2
**/
private static MBeanServerBuilder builder = null;
/**
* Provide a new {@link javax.management.MBeanServerBuilder}.
* @param builder The new MBeanServerBuilder that will be used to
* create {@link javax.management.MBeanServer}s.
* @exception IllegalArgumentException if the given builder is null.
*
* @exception SecurityException if there is a SecurityManager and
* the caller's permissions do not include or imply <code>{@link
* MBeanServerPermission}("setMBeanServerBuilder")</code>.
*
* @since.unbundled JMX 1.2
**/
// public static synchronized void
// setMBeanServerBuilder(MBeanServerBuilder builder) {
// checkPermission("setMBeanServerBuilder");
// MBeanServerFactory.builder = builder;
// }
/**
* Get the current {@link javax.management.MBeanServerBuilder}.
*
* @return the current {@link javax.management.MBeanServerBuilder}.
*
* @exception SecurityException if there is a SecurityManager and
* the caller's permissions do not include or imply <code>{@link
* MBeanServerPermission}("getMBeanServerBuilder")</code>.
*
* @since.unbundled JMX 1.2
**/
// public static synchronized MBeanServerBuilder getMBeanServerBuilder() {
// checkPermission("getMBeanServerBuilder");
// return builder;
// }
/**
* Remove internal MBeanServerFactory references to a created
* MBeanServer. This allows the garbage collector to remove the
* MBeanServer object.
*
* @param mbeanServer the MBeanServer object to remove.
*
* @exception java.lang.IllegalArgumentException if
* <code>mbeanServer</code> was not generated by one of the
* <code>createMBeanServer</code> methods, or if
* <code>releaseMBeanServer</code> was already called on it.
*
* @exception SecurityException if there is a SecurityManager and
* the caller's permissions do not include or imply <code>{@link
* MBeanServerPermission}("releaseMBeanServer")</code>.
*/
public static void releaseMBeanServer(MBeanServer mbeanServer) {
checkPermission("releaseMBeanServer");
removeMBeanServer(mbeanServer);
}
/**
* <p>Return a new object implementing the MBeanServer interface
* with a standard default domain name. The default domain name
* is used as the domain part in the ObjectName of MBeans when the
* domain is specified by the user is null.</p>
*
* <p>The standard default domain name is
* <code>DefaultDomain</code>.</p>
*
* <p>The MBeanServer reference is internally kept. This will
* allow <CODE>findMBeanServer</CODE> to return a reference to
* this MBeanServer object.</p>
*
* <p>This method is equivalent to <code>createMBeanServer(null)</code>.
*
* @return the newly created MBeanServer.
*
* @exception SecurityException if there is a SecurityManager and the
* caller's permissions do not include or imply <code>{@link
* MBeanServerPermission}("createMBeanServer")</code>.
*
* @exception JMRuntimeException if the property
* <code>javax.management.builder.initial</code> exists but the
* class it names cannot be instantiated through a public
* no-argument constructor; or if the instantiated builder returns
* null from its {@link MBeanServerBuilder#newMBeanServerDelegate
* newMBeanServerDelegate} or {@link
* MBeanServerBuilder#newMBeanServer newMBeanServer} methods.
*
* @exception ClassCastException if the property
* <code>javax.management.builder.initial</code> exists and can be
* instantiated but is not assignment compatible with {@link
* MBeanServerBuilder}.
*/
public static MBeanServer createMBeanServer() {
return createMBeanServer(null);
}
/**
* <p>Return a new object implementing the {@link MBeanServer}
* interface with the specified default domain name. The given
* domain name is used as the domain part in the ObjectName of
* MBeans when the domain is specified by the user is null.</p>
*
* <p>The MBeanServer reference is internally kept. This will
* allow <CODE>findMBeanServer</CODE> to return a reference to
* this MBeanServer object.</p>
*
* @param domain the default domain name for the created
* MBeanServer. This is the value that will be returned by {@link
* MBeanServer#getDefaultDomain}.
*
* @return the newly created MBeanServer.
*
* @exception SecurityException if there is a SecurityManager and
* the caller's permissions do not include or imply <code>{@link
* MBeanServerPermission}("createMBeanServer")</code>.
*
* @exception JMRuntimeException if the property
* <code>javax.management.builder.initial</code> exists but the
* class it names cannot be instantiated through a public
* no-argument constructor; or if the instantiated builder returns
* null from its {@link MBeanServerBuilder#newMBeanServerDelegate
* newMBeanServerDelegate} or {@link
* MBeanServerBuilder#newMBeanServer newMBeanServer} methods.
*
* @exception ClassCastException if the property
* <code>javax.management.builder.initial</code> exists and can be
* instantiated but is not assignment compatible with {@link
* MBeanServerBuilder}.
*/
public static MBeanServer createMBeanServer(String domain) {
checkPermission("createMBeanServer");
final MBeanServer mBeanServer = newMBeanServer(domain);
addMBeanServer(mBeanServer);
return mBeanServer;
}
/**
* <p>Return a new object implementing the MBeanServer interface
* with a standard default domain name, without keeping an
* internal reference to this new object. The default domain name
* is used as the domain part in the ObjectName of MBeans when the
* domain is specified by the user is null.</p>
*
* <p>The standard default domain name is
* <code>DefaultDomain</code>.</p>
*
* <p>No reference is kept. <CODE>findMBeanServer</CODE> will not
* be able to return a reference to this MBeanServer object, but
* the garbage collector will be able to remove the MBeanServer
* object when it is no longer referenced.</p>
*
* <p>This method is equivalent to <code>newMBeanServer(null)</code>.</p>
*
* @return the newly created MBeanServer.
*
* @exception SecurityException if there is a SecurityManager and the
* caller's permissions do not include or imply <code>{@link
* MBeanServerPermission}("newMBeanServer")</code>.
*
* @exception JMRuntimeException if the property
* <code>javax.management.builder.initial</code> exists but the
* class it names cannot be instantiated through a public
* no-argument constructor; or if the instantiated builder returns
* null from its {@link MBeanServerBuilder#newMBeanServerDelegate
* newMBeanServerDelegate} or {@link
* MBeanServerBuilder#newMBeanServer newMBeanServer} methods.
*
* @exception ClassCastException if the property
* <code>javax.management.builder.initial</code> exists and can be
* instantiated but is not assignment compatible with {@link
* MBeanServerBuilder}.
*/
public static MBeanServer newMBeanServer() {
return newMBeanServer(null);
}
/**
* <p>Return a new object implementing the MBeanServer interface
* with the specified default domain name, without keeping an
* internal reference to this new object. The given domain name
* is used as the domain part in the ObjectName of MBeans when the
* domain is specified by the user is null.</p>
*
* <p>No reference is kept. <CODE>findMBeanServer</CODE> will not
* be able to return a reference to this MBeanServer object, but
* the garbage collector will be able to remove the MBeanServer
* object when it is no longer referenced.</p>
*
* @param domain the default domain name for the created
* MBeanServer. This is the value that will be returned by {@link
* MBeanServer#getDefaultDomain}.
*
* @return the newly created MBeanServer.
*
* @exception SecurityException if there is a SecurityManager and the
* caller's permissions do not include or imply <code>{@link
* MBeanServerPermission}("newMBeanServer")</code>.
*
* @exception JMRuntimeException if the property
* <code>javax.management.builder.initial</code> exists but the
* class it names cannot be instantiated through a public
* no-argument constructor; or if the instantiated builder returns
* null from its {@link MBeanServerBuilder#newMBeanServerDelegate
* newMBeanServerDelegate} or {@link
* MBeanServerBuilder#newMBeanServer newMBeanServer} methods.
*
* @exception ClassCastException if the property
* <code>javax.management.builder.initial</code> exists and can be
* instantiated but is not assignment compatible with {@link
* MBeanServerBuilder}.
*/
public static MBeanServer newMBeanServer(String domain) {
checkPermission("newMBeanServer");
// Get the builder. Creates a new one if necessary.
//
final MBeanServerBuilder mbsBuilder = getNewMBeanServerBuilder();
// Returned value cannot be null. NullPointerException if violated.
synchronized(mbsBuilder) {
final MBeanServerDelegate delegate =
mbsBuilder.newMBeanServerDelegate();
if (delegate == null) {
final String msg =
"MBeanServerBuilder.newMBeanServerDelegate() " +
"returned null";
throw new JMRuntimeException(msg);
}
final MBeanServer mbeanServer =
mbsBuilder.newMBeanServer(domain,null,delegate);
if (mbeanServer == null) {
final String msg =
"MBeanServerBuilder.newMBeanServer() returned null";
throw new JMRuntimeException(msg);
}
return mbeanServer;
}
}
/**
* <p>Return a list of registered MBeanServer objects. A
* registered MBeanServer object is one that was created by one of
* the <code>createMBeanServer</code> methods and not subsequently
* released with <code>releaseMBeanServer</code>.</p>
*
* @param agentId The agent identifier of the MBeanServer to
* retrieve. If this parameter is null, all registered
* MBeanServers in this JVM are returned. Otherwise, only
* MBeanServers whose id is equal to <code>agentId</code> are
* returned. The id of an MBeanServer is the
* <code>MBeanServerId</code> attribute of its delegate MBean.
*
* @return A list of MBeanServer objects.
*
* @exception SecurityException if there is a SecurityManager and the
* caller's permissions do not include or imply <code>{@link
* MBeanServerPermission}("findMBeanServer")</code>.
*/
public synchronized static
ArrayList<MBeanServer> findMBeanServer(String agentId) {
checkPermission("findMBeanServer");
if (agentId == null)
return new ArrayList<MBeanServer>(mBeanServerList);
ArrayList<MBeanServer> result = new ArrayList<MBeanServer>();
for (MBeanServer mbs : mBeanServerList) {
String name = mBeanServerName(mbs);
if (agentId.equals(name))
result.add(mbs);
}
return result;
}
/**
* Return the ClassLoaderRepository used by the given MBeanServer.
* This method is equivalent to {@link MBeanServer#getClassLoaderRepository() server.getClassLoaderRepository()}.
* @param server The MBeanServer under examination. Since JMX 1.2,
* if <code>server</code> is <code>null</code>, the result is a
* {@link NullPointerException}. This behavior differs from what
* was implemented in JMX 1.1 - where the possibility to use
* <code>null</code> was deprecated.
* @return The Class Loader Repository used by the given MBeanServer.
* @exception SecurityException if there is a SecurityManager and
* the caller's permissions do not include or imply <code>{@link
* MBeanPermission}("getClassLoaderRepository")</code>.
*
* @exception NullPointerException if <code>server</code> is null.
*
* @since.unbundled JMX 1.1
**/
public static ClassLoaderRepository getClassLoaderRepository(
MBeanServer server) {
return server.getClassLoaderRepository();
}
private static String mBeanServerName(MBeanServer mbs) {
try {
return (String) mbs.getAttribute(MBeanServerDelegate.DELEGATE_NAME,
"MBeanServerId");
} catch (JMException e) {
return null;
}
}
private static void checkPermission(String action)
throws SecurityException {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
Permission perm = new MBeanServerPermission(action);
sm.checkPermission(perm);
}
}
private static synchronized void addMBeanServer(MBeanServer mbs) {
mBeanServerList.add(mbs);
}
private static synchronized void removeMBeanServer(MBeanServer mbs) {
boolean removed = mBeanServerList.remove(mbs);
if (!removed) {
trace("removeMBeanServer", "MBeanServer was not in list!");
throw new IllegalArgumentException("MBeanServer was not in list!");
}
}
private static final ArrayList<MBeanServer> mBeanServerList =
new ArrayList<MBeanServer>();
/**
* Load the builder class through the context class loader.
* @param builderClassName The name of the builder class.
**/
private static Class loadBuilderClass(String builderClassName)
throws ClassNotFoundException {
final ClassLoader loader =
Thread.currentThread().getContextClassLoader();
if (loader != null) {
// Try with context class loader
return loader.loadClass(builderClassName);
}
// No context class loader? Try with Class.forName()
return Class.forName(builderClassName);
}
/**
* Creates the initial builder according to the
* javax.management.builder.initial System property - if specified.
* If any checked exception needs to be thrown, it is embedded in
* a JMRuntimeException.
**/
private static MBeanServerBuilder newBuilder(Class builderClass) {
try {
final Object builder = builderClass.newInstance();
return (MBeanServerBuilder)builder;
} catch (RuntimeException x) {
throw x;
} catch (Exception x) {
final String msg =
"Failed to instantiate a MBeanServerBuilder from " +
builderClass + ": " + x;
throw new JMRuntimeException(msg, x);
}
}
/**
* Instantiate a new builder according to the
* javax.management.builder.initial System property - if needed.
**/
private static synchronized void checkMBeanServerBuilder() {
try {
GetPropertyAction act =
new GetPropertyAction(JmxProperties.JMX_INITIAL_BUILDER);
String builderClassName = AccessController.doPrivileged(act);
try {
final Class newBuilderClass;
if (builderClassName == null || builderClassName.length() == 0)
newBuilderClass = MBeanServerBuilder.class;
else
newBuilderClass = loadBuilderClass(builderClassName);
// Check whether a new builder needs to be created
if (builder != null) {
final Class builderClass = builder.getClass();
if (newBuilderClass == builderClass)
return; // no need to create a new builder...
}
// Create a new builder
builder = newBuilder(newBuilderClass);
} catch (ClassNotFoundException x) {
final String msg =
"Failed to load MBeanServerBuilder class " +
builderClassName + ": " + x;
throw new JMRuntimeException(msg, x);
}
} catch (RuntimeException x) {
debug("checkMBeanServerBuilder",
"Failed to instantiate MBeanServerBuilder: " + x +
"\n\t\tCheck the value of the " +
JmxProperties.JMX_INITIAL_BUILDER + " property." );
throw x;
}
}
/**
* Get the current {@link javax.management.MBeanServerBuilder},
* as specified by the current value of the
* javax.management.builder.initial property.
*
* This method consults the property and instantiates a new builder
* if needed.
*
* @return the new current {@link javax.management.MBeanServerBuilder}.
*
* @exception SecurityException if there is a SecurityManager and
* the caller's permissions do not make it possible to instantiate
* a new builder.
* @exception JMRuntimeException if the builder instantiation
* fails with a checked exception -
* {@link java.lang.ClassNotFoundException} etc...
*
* @since.unbundled JMX 1.2
**/
private static synchronized MBeanServerBuilder getNewMBeanServerBuilder() {
checkMBeanServerBuilder();
return builder;
}
/** Private Stuff **/
private static void trace(String method, String message) {
if (Trace.isSelected(Trace.LEVEL_TRACE, Trace.INFO_MBEANSERVER)) {
Trace.send(Trace.LEVEL_TRACE, Trace.INFO_MBEANSERVER,
MBeanServerFactory.class.getName(), method, message);
}
}
/** Private Stuff **/
private static void debug(String method, String message) {
if (Trace.isSelected(Trace.LEVEL_DEBUG, Trace.INFO_MBEANSERVER)) {
Trace.send(Trace.LEVEL_DEBUG, Trace.INFO_MBEANSERVER,
MBeanServerFactory.class.getName(), method, message);
}
}
/** Private Stuff **/
private static void error(String method, String message) {
if (Trace.isSelected(Trace.LEVEL_ERROR, Trace.INFO_MBEANSERVER)) {
Trace.send(Trace.LEVEL_ERROR, Trace.INFO_MBEANSERVER,
MBeanServerFactory.class.getName(), method, message);
}
}
}
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