org.apache.river.landlord

Class ConstrainableLandlordLease

java.lang.Object

org.apache.river.lease.AbstractLease

org.apache.river.landlord.LandlordLease

org.apache.river.landlord.ConstrainableLandlordLease

All Implemented Interfaces:

Serializable, RemoteMethodControl, Lease, ReferentUuid, ID<Uuid>

public final class ConstrainableLandlordLease
extends LandlordLease
implements RemoteMethodControl

Constrainable sub-class of LandlordLease. Instances of this class can be verified using the LandlordProxyVerifier class.

Since:

2.0

Author:

Sun Microsystems, Inc.

See Also:

LandlordProxyVerifier, Serialized Form

Field Summary

Fields inherited from class org.apache.river.lease.AbstractLease

expiration, serialFormat

Fields inherited from interface net.jini.core.lease.Lease

ABSOLUTE, ANY, DURATION, FOREVER

Constructor Summary

Constructors

Constructor and Description
ConstrainableLandlordLease(Uuid cookie, Landlord landlord, Uuid landlordUuid, long expiration, MethodConstraints methodConstraints) Create a new ConstrainableLandlordLease.

Method Summary

Modifier and Type	Method and Description
boolean	canBatch(Lease lease) Returns a boolean indicating whether or not the lease given as a parameter can be batched (placed in the same LeaseMap) with the current lease.
LeaseMap	createLeaseMap(long duration) Creates a Map object that can contain leases whose renewal or cancellation can be batched, and adds the current lease to that map.
MethodConstraints	getConstraints() Returns the client constraints placed on this proxy.
RemoteMethodControl	setConstraints(MethodConstraints constraints) Returns a new copy of this proxy with the client constraints set to the specified constraints.

Methods inherited from class org.apache.river.landlord.LandlordLease

cancel, doRenew, equals, getReferentUuid, hashCode, identity, toString

Methods inherited from class org.apache.river.lease.AbstractLease

getExpiration, getSerialFormat, renew, setSerialFormat

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ConstrainableLandlordLease

public ConstrainableLandlordLease(Uuid cookie,
                                  Landlord landlord,
                                  Uuid landlordUuid,
                                  long expiration,
                                  MethodConstraints methodConstraints)

Create a new ConstrainableLandlordLease.

Parameters:

cookie - a Uuid that universally and uniquely identifies the lease this object is to be a proxy for

landlord - Landlord object that will be used to communicate renew and cancel requests to the granter of the lease.

landlordUuid - a universally unique id that has been assigned to the server granting of the lease. Ideally the Uuid landlord.getUuid would return if landlord implemented ReferentUuid. Used to determine when two leases can be batched together.

expiration - The initial expiration time of the lease in milliseconds since the beginning of the epoch.

methodConstraints - the client method constraints to place on this proxy (may be null).

Throws:

NullPointerException - if landlord, landlordUuid, or cookie is null.

ClassCastException - if landlord does not implement RemoteMethodControl.

Method Detail

setConstraints

public RemoteMethodControl setConstraints(MethodConstraints constraints)

Description copied from interface: RemoteMethodControl

Returns a new copy of this proxy with the client constraints set to the specified constraints. These constraints completely replace (in the copy) any client constraints previously placed on this proxy; calling the getConstraints method of the copy returns the identical constraints instance. The original proxy is not modified. A null value is interpreted as mapping all methods to empty constraints (one that has no requirements and no preferences). For any given remote call, the specific client requirements and preferences to be satisfied are given by the return value of invoking the getConstraints method of the specified MethodConstraints instance with a Method object representing the remote method.

Client constraints placed on a proxy are included in the serialized state of the proxy. This allows third-party services to be transparent to the client's needs. For example, if remote object s1 obtains a proxy for remote object s2, and passes that proxy to remote object s3, expecting s3 to invoke a remote method on s2, then s1 can control that call by placing its constraints directly on the proxy before passing it to s3. If s3 does not wish to be transparent in this way, then it should explicitly replace the client constraints on received proxies with whatever constraints are appropriate to implement its own policy.

Specified by:

setConstraints in interface RemoteMethodControl

Parameters:

constraints - client constraints, or null

Returns:

a new copy of this proxy with the client constraints set to the specified constraints

See Also:

RemoteMethodControl.getConstraints()

getConstraints

public MethodConstraints getConstraints()

Description copied from interface: RemoteMethodControl

Returns the client constraints placed on this proxy. The return value can be null, which is interpreted as mapping all methods to empty constraints (one that has no requirements and no preferences).

Specified by:

getConstraints in interface RemoteMethodControl

Returns:

the client constraints, or null

See Also:

RemoteMethodControl.setConstraints(net.jini.core.constraint.MethodConstraints)

canBatch

public boolean canBatch(Lease lease)

Description copied from interface: Lease

Returns a boolean indicating whether or not the lease given as a parameter can be batched (placed in the same LeaseMap) with the current lease. Whether or not two Lease objects can be batched is an implementation detail determined by the objects.

Specified by:

canBatch in interface Lease

Overrides:

canBatch in class LandlordLease

Parameters:

lease - the Lease to be evaluated

Returns:

a boolean indicating whether or not the lease given as a parameter can be batched (placed in the same LeaseMap) with the current lease

createLeaseMap

public LeaseMap createLeaseMap(long duration)

Description copied from interface: Lease

Creates a Map object that can contain leases whose renewal or cancellation can be batched, and adds the current lease to that map. The current lease is put in the map with the duration value given by the parameter.

Specified by:

createLeaseMap in interface Lease

Overrides:

createLeaseMap in class LandlordLease

Parameters:

duration - the duration to put into a Long and use as the value for the current lease in the created LeaseMap

Returns:

the created LeaseMap object