1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18 package org.apache.river.reggie.proxy;
19
20 import java.io.IOException;
21 import java.io.InvalidObjectException;
22 import java.io.ObjectOutputStream;
23 import java.io.ObjectStreamException;
24 import java.rmi.RemoteException;
25 import net.jini.core.constraint.RemoteMethodControl;
26 import net.jini.core.lease.UnknownLeaseException;
27 import net.jini.core.lookup.ServiceID;
28 import net.jini.id.Uuid;
29 import org.apache.river.api.io.AtomicSerial;
30 import org.apache.river.api.io.AtomicSerial.GetArg;
31
32 /**
33 * When a registrar (lookup service) grants a lease on an event registration
34 * on behalf of some object (client), a proxy is employed to allow the client
35 * to interact with the lease; this class is the implementation of that proxy.
36 * Clients only see instances of this class via the Lease interface.
37 *
38 * @author Sun Microsystems, Inc.
39 *
40 */
41 @AtomicSerial
42 public class EventLease extends RegistrarLease {
43
44 private static final long serialVersionUID = 2L;
45 /** The type of the lease used in toString() calls. */
46 private static final String LEASE_TYPE = "event";
47
48 /**
49 * The eventID returned in the EventRegistration.
50 *
51 * @serial
52 */
53 final long eventID;
54
55 /**
56 * Returns EventLease or ConstrainableEventLease instance, depending on
57 * whether given server implements RemoteMethodControl.
58 */
59 public static EventLease getInstance(Registrar server,
60 ServiceID registrarID,
61 long eventID,
62 Uuid leaseID,
63 long expiration)
64 {
65 return (server instanceof RemoteMethodControl) ?
66 new ConstrainableEventLease(
67 server, registrarID, eventID, leaseID, expiration, null, true) :
68 new EventLease(server, registrarID, eventID, leaseID, expiration);
69 }
70
71 private static GetArg check(GetArg arg) throws IOException{
72 long eventID = arg.get("eventID", 0L);
73 return arg;
74 }
75
76 EventLease(GetArg arg) throws IOException{
77 super(check(arg));
78 eventID = arg.get("eventID", 0L);
79 }
80
81 /** Constructor for use by getInstance(), ConstrainableEventLease. */
82 EventLease(Registrar server,
83 ServiceID registrarID,
84 long eventID,
85 Uuid leaseID,
86 long expiration)
87 {
88 super(server, registrarID, leaseID, expiration);
89 this.eventID = eventID;
90 }
91
92 // This method's javadoc is inherited from an interface of this class
93 public void cancel() throws UnknownLeaseException, RemoteException {
94 server.cancelEventLease(eventID, leaseID);
95 }
96
97 /**
98 * Renews the event lease associated with an instance of this class.
99 * Each instance of this class corresponds to a lease on an event
100 * registration for a particular client. This method renews that
101 * lease on behalf of the client.
102 *
103 * @param duration the requested duration for the lease being renewed
104 * @return long value representing the new duration that was granted
105 * for the renewed lease. Note that the duration returned may
106 * be less than the duration requested.
107 * @exception UnknownLeaseException indicates the lease does not exist;
108 * typically because the lease has expired.
109 */
110 protected long doRenew(long duration)
111 throws UnknownLeaseException, RemoteException
112 {
113 return server.renewEventLease(eventID, leaseID, duration);
114 }
115
116 // This method's javadoc is inherited from a super class of this class
117 Object getRegID() {
118 return Long.valueOf(eventID);
119 }
120
121 // inherit javadoc
122 String getLeaseType() {
123 return LEASE_TYPE;
124 }
125
126 private void writeObject(ObjectOutputStream out) throws IOException {
127 out.defaultWriteObject();
128 }
129
130 /**
131 * Throws InvalidObjectException, since data for this class is required.
132 */
133 private void readObjectNoData() throws ObjectStreamException {
134 throw new InvalidObjectException("no data");
135 }
136 }