ServiceLease.java

/*
 * 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 com.sun.jini.reggie;

import java.rmi.RemoteException;
import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamException;
import net.jini.core.constraint.RemoteMethodControl;
import net.jini.core.lease.UnknownLeaseException;
import net.jini.core.lookup.ServiceID;
import net.jini.id.Uuid;

/**
 * A ServiceLease is a proxy for a service registration lease at a registrar.
 * Clients only see instances via the Lease interface.
 *
 * @author Sun Microsystems, Inc.
 *
 */
class ServiceLease extends RegistrarLease {

    private static final long serialVersionUID = 2L;
    /** The type of the lease used in toString() calls. */
    private static final String LEASE_TYPE = "service";   

    /**
     * The service id assigned at registration.
     */
    transient ServiceID serviceID;

    /**
     * Returns ServiceLease or ConstrainableServiceLease instance, depending on
     * whether given server implements RemoteMethodControl.
     */
    static ServiceLease getInstance(Registrar server,
				    ServiceID registrarID,
				    ServiceID serviceID,
				    Uuid leaseID,
				    long expiration)
    {
	return (server instanceof RemoteMethodControl) ?
	    new ConstrainableServiceLease(
		server, registrarID, serviceID, leaseID, expiration, null) :
	    new ServiceLease(
		server, registrarID, serviceID, leaseID, expiration);
    }

    /** Constructor for use by getInstance(), ConstrainableServiceLease. */
    ServiceLease(Registrar server,
		 ServiceID registrarID,
		 ServiceID serviceID,
		 Uuid leaseID,
		 long expiration)
    {
	super(server, registrarID, leaseID, expiration);
	this.serviceID = serviceID;
    }

    public void cancel() throws UnknownLeaseException, RemoteException {
	server.cancelServiceLease(serviceID, leaseID);
    }

    /** Do the actual renew. */
    protected long doRenew(long duration)
	throws UnknownLeaseException, RemoteException
    {
	return server.renewServiceLease(serviceID, leaseID, duration);
    }

    /** Returns the service ID */
    ServiceID getServiceID() {
	return serviceID;
    }

    Object getRegID() {
	return serviceID;
    }
    
    // This method's javadoc is inherited from a super class of this class
    String getLeaseType() {
	return LEASE_TYPE;
    }

    /**
     * Writes the service ID, encoded as specified by the ServiceID.writeBytes
     * method.
     */
    private void writeObject(ObjectOutputStream out) throws IOException {
	out.defaultWriteObject();
	serviceID.writeBytes(out);
    }

    /**
     * Reads the service ID, encoded as specified by the ServiceID.writeBytes
     * method.
     */
    private void readObject(ObjectInputStream in)
	throws IOException, ClassNotFoundException
    {
	in.defaultReadObject();
	serviceID = new ServiceID(in);
    }

    /**
     * Throws InvalidObjectException, since data for this class is required.
     */
    private void readObjectNoData() throws ObjectStreamException {
	throw new InvalidObjectException("no data");
    }
}