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Mbean Auto Registration

This example shows how to automatically create and register mbeans using TomEE features.

Dependencies

To be able to use it you need to import the mbean api (annotations):

<dependency>
  <groupId>org.apache.openejb</groupId>
  <artifactId>mbean-annotation-api</artifactId>
  <version>4.5.0</version>
  <scope>provided</scope>
</dependency>

The MBean

The mbean implements a simple game where the goal is to guess a number.

It allows the user to change the value too.

package org.superbiz.mbean;

import javax.management.Description;
import javax.management.MBean;
import javax.management.ManagedAttribute;
import javax.management.ManagedOperation;

@MBean
@Description("play with me to guess a number")
public class GuessHowManyMBean {
    private int value = 0;

    @ManagedAttribute
    @Description("you are cheating!")
    public int getValue() {
        return value;
    }

    @ManagedAttribute
    public void setValue(int value) {
        this.value = value;
    }

    @ManagedOperation
    public String tryValue(int userValue) {
        if (userValue == value) {
            return "winner";
        }
        return "not the correct value, please have another try";
    }
}

To register a MBean you simply have to specify a property either in system.properties, or in intial context properties.

Properties properties = new Properties();
properties.setProperty("openejb.user.mbeans.list", GuessHowManyMBean.class.getName());
EJBContainer.createEJBContainer(properties);

Accessing the MBean

Then simply get the platform server and you can play with parameters and operations:

package org.superbiz.mbean;

import org.junit.Test;

import jakarta.ejb.embeddable.EJBContainer;
import javax.management.Attribute;
import javax.management.MBeanInfo;
import javax.management.MBeanServer;
import javax.management.ObjectName;
import java.lang.management.ManagementFactory;
import java.util.Properties;

import static junit.framework.Assert.assertEquals;

public class GuessHowManyMBeanTest {
    private static final String OBJECT_NAME = "openejb.user.mbeans:group=org.superbiz.mbean,application=mbean-auto-registration,name=GuessHowManyMBean";

    @Test
    public void play() throws Exception {
        Properties properties = new Properties();
        properties.setProperty("openejb.user.mbeans.list", GuessHowManyMBean.class.getName());
        EJBContainer container = EJBContainer.createEJBContainer(properties);

        MBeanServer server = ManagementFactory.getPlatformMBeanServer();
        ObjectName objectName = new ObjectName(OBJECT_NAME);
        MBeanInfo infos = server.getMBeanInfo(objectName);
        assertEquals(0, server.getAttribute(objectName, "value"));
        server.setAttribute(objectName, new Attribute("value", 3));
        assertEquals(3, server.getAttribute(objectName, "value"));
        assertEquals("winner", server.invoke(objectName, "tryValue", new Object[]{3}, null));
        assertEquals("not the correct value, please have another try", server.invoke(objectName, "tryValue", new Object[]{2}, null));

        container.close();
    }
}

Note

If OpenEJB can’t find any module it can’t start. So to force him to start even if the example has only the mbean as java class, we added a beans.xml file to turn our project into a Java EE module.

Running

-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running org.superbiz.mbean.GuessHowManyMBeanTest
Apache OpenEJB 4.0.0-beta-1    build: 20111002-04:06
http://tomee.apache.org/
INFO - openejb.home = /Users/dblevins/examples/mbean-auto-registration
INFO - openejb.base = /Users/dblevins/examples/mbean-auto-registration
INFO - Using 'jakarta.ejb.embeddable.EJBContainer=true'
INFO - Configuring Service(id=Default Security Service, type=SecurityService, provider-id=Default Security Service)
INFO - Configuring Service(id=Default Transaction Manager, type=TransactionManager, provider-id=Default Transaction Manager)
INFO - Found EjbModule in classpath: /Users/dblevins/examples/mbean-auto-registration/target/classes
INFO - Beginning load: /Users/dblevins/examples/mbean-auto-registration/target/classes
INFO - Configuring enterprise application: /Users/dblevins/examples/mbean-auto-registration
INFO - MBean openejb.user.mbeans:application=,group=org.superbiz.mbean,name=GuessHowManyMBean registered.
INFO - MBean openejb.user.mbeans:application=mbean-auto-registration,group=org.superbiz.mbean,name=GuessHowManyMBean registered.
INFO - MBean openejb.user.mbeans:application=EjbModule1847652919,group=org.superbiz.mbean,name=GuessHowManyMBean registered.
INFO - Configuring Service(id=Default Managed Container, type=Container, provider-id=Default Managed Container)
INFO - Auto-creating a container for bean mbean-auto-registration.Comp: Container(type=MANAGED, id=Default Managed Container)
INFO - Enterprise application "/Users/dblevins/examples/mbean-auto-registration" loaded.
INFO - Assembling app: /Users/dblevins/examples/mbean-auto-registration
INFO - Jndi(name="java:global/mbean-auto-registration/mbean-auto-registration.Comp!org.apache.openejb.BeanContext$Comp")
INFO - Jndi(name="java:global/mbean-auto-registration/mbean-auto-registration.Comp")
INFO - Jndi(name="java:global/EjbModule1847652919/org.superbiz.mbean.GuessHowManyMBeanTest!org.superbiz.mbean.GuessHowManyMBeanTest")
INFO - Jndi(name="java:global/EjbModule1847652919/org.superbiz.mbean.GuessHowManyMBeanTest")
INFO - Created Ejb(deployment-id=mbean-auto-registration.Comp, ejb-name=mbean-auto-registration.Comp, container=Default Managed Container)
INFO - Created Ejb(deployment-id=org.superbiz.mbean.GuessHowManyMBeanTest, ejb-name=org.superbiz.mbean.GuessHowManyMBeanTest, container=Default Managed Container)
INFO - Started Ejb(deployment-id=mbean-auto-registration.Comp, ejb-name=mbean-auto-registration.Comp, container=Default Managed Container)
INFO - Started Ejb(deployment-id=org.superbiz.mbean.GuessHowManyMBeanTest, ejb-name=org.superbiz.mbean.GuessHowManyMBeanTest, container=Default Managed Container)
INFO - Deployed Application(path=/Users/dblevins/examples/mbean-auto-registration)
INFO - Undeploying app: /Users/dblevins/examples/mbean-auto-registration
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 1.063 sec

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

APIs Used