Java Dynamic Management Kit 4.1 Tutorial

Agent Administration

Preparation

Go back to the agent view by clicking the link near the top of the MBean view page. Then click on the "Admin" button in the agent view to bring up the agent administration page in your browser window.

The agent administration page contains a form for entering MBean information when creating or unregistering MBeans. You may also instantiate an MBean through one of its public constructors. In order to instantiate an MBean, its class must be available in the agent application's classpath. Optionally, you may specify a different class loader in the appropriate field if the agent contains other class loader MBeans.

The first two fields, "Domain" and "Keys" are mandatory for all administrative actions. The "Domain" field initially contains the string representing the agent's default domain. Together, these fields define the object name, whether for a new MBean to be created or the name of an existing MBean to unregister. The "Java Class" is the full class name of the object to be instantiated as a new MBean. This field is ignored when unregistering an MBean.

Using the drop-down menu, you may select one of three actions on this page:

Create - Instantiates the given Java class of an MBean and registers the new instance in the MBean server. If successful, the MBean will then appear in the agent view. The class must have a public constructor without parameters in order to be created in this way.
Unregister - Unregisters an MBean from the MBean server so that it is no longer available in the agent. The class instance is not explicitly deleted, though if no other references to it exist, it will be garbage collected.
Constructors - Displays the list of public constructors at the bottom of the administration page for the given Java class. This lets you provide parameters to a specific constructor and create the MBean in this manner. This is the only way to create MBeans which do not have a no-parameter constructor.

When you click the "Send Request" button, the HTML adaptor processes the action and updates the bottom of the page with the action results. You may have to scroll down to see the result. The text fields are not cleared after a request so that you can do multiple operations. The "Reset" button will return the fields to their last posted value after you have modified them.