| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.cassandra.utils; |
| |
| import java.lang.management.ManagementFactory; |
| import java.util.function.Consumer; |
| import javax.management.MBeanServer; |
| import javax.management.MalformedObjectNameException; |
| import javax.management.ObjectName; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import static org.apache.cassandra.config.CassandraRelevantProperties.IS_DISABLED_MBEAN_REGISTRATION; |
| import static org.apache.cassandra.config.CassandraRelevantProperties.MBEAN_REGISTRATION_CLASS; |
| |
| /** |
| * Helper class to avoid catching and rethrowing checked exceptions on MBean and |
| * allow turning of MBean registration for test purposes. |
| */ |
| public interface MBeanWrapper |
| { |
| static final Logger logger = LoggerFactory.getLogger(MBeanWrapper.class); |
| |
| static final MBeanWrapper instance = create(); |
| |
| static MBeanWrapper create() |
| { |
| if (IS_DISABLED_MBEAN_REGISTRATION.getBoolean()) |
| return new NoOpMBeanWrapper(); |
| |
| String klass = MBEAN_REGISTRATION_CLASS.getString(); |
| if (klass == null) |
| return new PlatformMBeanWrapper(); |
| return FBUtilities.construct(klass, "mbean"); |
| } |
| |
| // Passing true for graceful will log exceptions instead of rethrowing them |
| public void registerMBean(Object obj, ObjectName mbeanName, OnException onException); |
| default void registerMBean(Object obj, ObjectName mbeanName) |
| { |
| registerMBean(obj, mbeanName, OnException.THROW); |
| } |
| |
| default void registerMBean(Object obj, String mbeanName, OnException onException) |
| { |
| ObjectName name = create(mbeanName, onException); |
| if (name == null) |
| return; |
| registerMBean(obj, name, onException); |
| } |
| default void registerMBean(Object obj, String mbeanName) |
| { |
| registerMBean(obj, mbeanName, OnException.THROW); |
| } |
| |
| public boolean isRegistered(ObjectName mbeanName, OnException onException); |
| default boolean isRegistered(ObjectName mbeanName) |
| { |
| return isRegistered(mbeanName, OnException.THROW); |
| } |
| |
| default boolean isRegistered(String mbeanName, OnException onException) |
| { |
| ObjectName name = create(mbeanName, onException); |
| if (name == null) |
| return false; |
| return isRegistered(name, onException); |
| } |
| default boolean isRegistered(String mbeanName) |
| { |
| return isRegistered(mbeanName, OnException.THROW); |
| } |
| |
| public void unregisterMBean(ObjectName mbeanName, OnException onException); |
| default void unregisterMBean(ObjectName mbeanName) |
| { |
| unregisterMBean(mbeanName, OnException.THROW); |
| } |
| |
| default void unregisterMBean(String mbeanName, OnException onException) |
| { |
| ObjectName name = create(mbeanName, onException); |
| if (name == null) |
| return; |
| unregisterMBean(name, onException); |
| } |
| default void unregisterMBean(String mbeanName) |
| { |
| unregisterMBean(mbeanName, OnException.THROW); |
| } |
| |
| static ObjectName create(String mbeanName, OnException onException) |
| { |
| try |
| { |
| return new ObjectName(mbeanName); |
| } |
| catch (MalformedObjectNameException e) |
| { |
| onException.handler.accept(e); |
| return null; |
| } |
| } |
| |
| static class NoOpMBeanWrapper implements MBeanWrapper |
| { |
| public void registerMBean(Object obj, ObjectName mbeanName, OnException onException) {} |
| public void registerMBean(Object obj, String mbeanName, OnException onException) {} |
| public boolean isRegistered(ObjectName mbeanName, OnException onException) { return false; } |
| public boolean isRegistered(String mbeanName, OnException onException) { return false; } |
| public void unregisterMBean(ObjectName mbeanName, OnException onException) {} |
| public void unregisterMBean(String mbeanName, OnException onException) {} |
| } |
| |
| static class PlatformMBeanWrapper implements MBeanWrapper |
| { |
| private final MBeanServer mbs = ManagementFactory.getPlatformMBeanServer(); |
| public void registerMBean(Object obj, ObjectName mbeanName, OnException onException) |
| { |
| try |
| { |
| mbs.registerMBean(obj, mbeanName); |
| } |
| catch (Exception e) |
| { |
| onException.handler.accept(e); |
| } |
| } |
| |
| public boolean isRegistered(ObjectName mbeanName, OnException onException) |
| { |
| try |
| { |
| return mbs.isRegistered(mbeanName); |
| } |
| catch (Exception e) |
| { |
| onException.handler.accept(e); |
| } |
| return false; |
| } |
| |
| public void unregisterMBean(ObjectName mbeanName, OnException onException) |
| { |
| try |
| { |
| mbs.unregisterMBean(mbeanName); |
| } |
| catch (Exception e) |
| { |
| onException.handler.accept(e); |
| } |
| } |
| } |
| |
| public enum OnException |
| { |
| THROW(e -> { throw new RuntimeException(e); }), |
| LOG(e -> { logger.error("Error in MBean wrapper: ", e); }), |
| IGNORE(e -> {}); |
| |
| public final Consumer<Exception> handler; |
| OnException(Consumer<Exception> handler) |
| { |
| this.handler = handler; |
| } |
| } |
| } |