With this example we are going to demonstrate how to list all JVM MBeans. An MBean is a managed Java object, similar to a JavaBeans component, that follows the design patterns set forth in the JMX specification. An MBean can represent a device, an application, or any resource that needs to be managed. MBeans expose a management interface that consists of a set of readable or writable attributes, or both, a set of invokable operations and a self-description. In short, to list all JVM MBeans you should:
- Create an MBeanServer that is the interface for MBean manipulation on the agent side. Use
getPlatformMBeanServer()API method of ManagementFactory. - Use
queryMBeans(ObjectName name, QueryExp query)API method of MBeanServer to get all the MBeans controlled by this MBean server. Since all parameters are set tonullall MBeans are to be selected. - Iterate over the Set of ObjectInstance objects to get the name and class of each MBean.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.enterprise;
import java.lang.management.ManagementFactory;
import java.util.Iterator;
import java.util.Set;
import javax.management.MBeanServer;
import javax.management.ObjectInstance;
public class ListAllJVMMBeans {
public static void main(String[] args) throws Exception {
MBeanServer server = ManagementFactory.getPlatformMBeanServer();
Set<ObjectInstance> instances = server.queryMBeans(null, null);
Iterator<ObjectInstance> iterator = instances.iterator();
while (iterator.hasNext()) {
ObjectInstance instance = iterator.next();
System.out.println("MBean Found:");
System.out.println("Class Name:t" + instance.getClassName());
System.out.println("Object Name:t" + instance.getObjectName());
System.out.println("****************************************");
}
}
}
Output:
MBean Found:
Class Name: com.sun.management.OperatingSystem
Object Name: java.lang:type=OperatingSystem
****************************************
MBean Found:
Class Name: sun.management.MemoryPoolImpl
Object Name: java.lang:type=MemoryPool,name=Tenured Gen
****************************************
MBean Found:
Class Name: sun.management.MemoryPoolImpl
Object Name: java.lang:type=MemoryPool,name=Perm Gen
****************************************
MBean Found:
Class Name: java.util.logging.Logging
Object Name: java.util.logging:type=Logging
****************************************
MBean Found:
Class Name: sun.management.CompilationImpl
Object Name: java.lang:type=Compilation
****************************************
MBean Found:
Class Name: javax.management.MBeanServerDelegate
Object Name: JMImplementation:type=MBeanServerDelegate
****************************************
MBean Found:
Class Name: sun.management.MemoryImpl
Object Name: java.lang:type=Memory
****************************************
MBean Found:
Class Name: sun.management.MemoryPoolImpl
Object Name: java.lang:type=MemoryPool,name=Survivor Space
****************************************
MBean Found:
Class Name: sun.management.RuntimeImpl
Object Name: java.lang:type=Runtime
****************************************
MBean Found:
Class Name: sun.management.GarbageCollectorImpl
Object Name: java.lang:type=GarbageCollector,name=Copy
****************************************
MBean Found:
Class Name: sun.management.MemoryPoolImpl
Object Name: java.lang:type=MemoryPool,name=Eden Space
****************************************
MBean Found:
Class Name: sun.management.GarbageCollectorImpl
Object Name: java.lang:type=GarbageCollector,name=MarkSweepCompact
****************************************
MBean Found:
Class Name: sun.management.ThreadImpl
Object Name: java.lang:type=Threading
****************************************
MBean Found:
Class Name: sun.management.MemoryPoolImpl
Object Name: java.lang:type=MemoryPool,name=Perm Gen [shared-ro]
****************************************
MBean Found:
Class Name: sun.management.MemoryPoolImpl
Object Name: java.lang:type=MemoryPool,name=Perm Gen [shared-rw]
****************************************
MBean Found:
Class Name: sun.management.HotSpotDiagnostic
Object Name: com.sun.management:type=HotSpotDiagnostic
****************************************
MBean Found:
Class Name: sun.management.ClassLoadingImpl
Object Name: java.lang:type=ClassLoading
****************************************
MBean Found:
Class Name: sun.management.MemoryManagerImpl
Object Name: java.lang:type=MemoryManager,name=CodeCacheManager
****************************************
MBean Found:
Class Name: sun.management.MemoryPoolImpl
Object Name: java.lang:type=MemoryPool,name=Code Cache
****************************************
This was an example of how to list all JVM MBeans.
