Using JMX with Enterprise JavaBeans - JMX in Action - page 358

This entity bean represents a row in a relational database table with two col-
umns: clientid and state. The EJB consists of its home interface, its remote inter-
face, and the main bean class, which are named WorkflowHome , Workflow , and
WorkflowBean , respectively.
The home interface
The following is Workflow EJB 's home interface:
package jmxbook.ch14;
import javax.ejb.*;
import java.rmi.*;
import java.util.*;
public interface WorkflowHome extends EJBHome
{
public Workflow create( String clientID ) throws CreateException,
RemoteException;
public Workflow findByPrimaryKey( String clientID )
throws FinderException,
RemoteException;
}
The EJB home interface enables clients to look up or create a WorkflowBean for
use. The home interface gives you one method for creating a WorkflowBean
instance and one method for looking up an existing instance. Both methods take
a String clientID as an argument. In our scenario, this parameter represents a
unique user ID for this particular workflow process.
The MBean that manages this EJB will always use the lookup method rather
than the create method, because the EJB has to exist in order to create the MBean.
The remote interface
The following is the remote interface for the EJB :
package jmxbook.ch14;
import java.rmi.*;
import javax.ejb.*;
public interface Workflow extends EJBObject
{
public void advanceState() throws RemoteException;
public String getState() throws RemoteException;
public void setState( String state ) throws RemoteException;
}
The EJB remote interface declares the methods that EJB uses to interact with the
bean. The advanceState() method tells the Workflow EJB to move the workflow to
the next step in the overall process, the getState() method returns the current