Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
/*
* Copyright (c) 2002-2007 Sun Microsystems, Inc. All rights reserved.
*
* The Sun Project JXTA(TM) Software License
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. The end-user documentation included with the redistribution, if any, must
* include the following acknowledgment: "This product includes software
* developed by Sun Microsystems, Inc. for JXTA(TM) technology."
* Alternately, this acknowledgment may appear in the software itself, if
* and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
* not be used to endorse or promote products derived from this software
* without prior written permission. For written permission, please contact
* Project JXTA at http://www.jxta.org.
*
* 5. Products derived from this software may not be called "JXTA", nor may
* "JXTA" appear in their name, without prior written permission of Sun.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SUN
* MICROSYSTEMS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* JXTA is a registered trademark of Sun Microsystems, Inc. in the United
* States and other countries.
*
* Please see the license information page at :
* for instructions on use of
* the license in source files.
*
* ====================================================================
*
* This software consists of voluntary contributions made by many individuals
* on behalf of Project JXTA. For more information on Project JXTA, please see
* http://www.jxta.org.
*
* This license is based on the BSD license adopted by the Apache Foundation.
*/
package net.jxta.impl.peergroup;
import net.jxta.exception.ServiceNotFoundException;
import net.jxta.id.ID;
import net.jxta.peergroup.PeerGroup;
import net.jxta.service.Service;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.Map;
/**
* RefCountPeerGroupInterface is a PeerGroupInterface object that
* also serves as a peergroup very-strong reference. When the last
* such goes away, the peergroup terminates itself despite the existence
* of aeternal strong references from the various service's threads
* that would prevent it from ever being finalized.
* The alternative: to give only weak references to threads seems impractical.
*/
class RefCountPeerGroupInterface extends PeerGroupInterface {
private Map roleMap;
/**
* Constructs an interface object that front-ends a given
* PeerGroup object.
*
* @param theRealThing the peer group
*/
RefCountPeerGroupInterface(GenericPeerGroup theRealThing) {
super(theRealThing);
}
RefCountPeerGroupInterface(GenericPeerGroup theRealThing, Map roleMap) {
super(theRealThing);
this.roleMap = roleMap;
}
/**
* {@inheritDoc}
*
* Normally it is ignored. By definition, the interface object
* protects the real object's start/stop methods from being called.
*
* However we have to make an exception for groups: even the creator
* of a group does not have access to the real object. So the interface
* has to forward startApp to the group, which is responsible for
* ensuring that it is executed only once (if needed).
*
* @param arg A table of strings arguments.
* @return int status indication.
*/
@Override
public int startApp(String[] arg) {
// Unlike our superclass's method, we do call the real
// startApp method.
PeerGroup temp = groupImpl;
if (null == temp) {
throw new IllegalStateException("This Peer Group interface object has been unreferenced and can no longer be used.");
}
return temp.startApp(arg);
}
/**
* {@inheritDoc}
*
* This is here for temporary class hierarchy reasons.
* it is normally ignored. By definition, the interface object
* protects the real object's start/stop methods from being called
*
* In that case we have to make an exception. Most applications
* currently assume that they do not share the group object and that they do
* refer to the real object directly. They call stopApp to signify their
* intention of no-longer using the group. Now that groups are shared,
* we convert stopApp() to unref() for compatibility.
* We could also just do nothing and let the interface be GC'd but
* calling unref() makes the group go away immediately if not shared,
* which is what applications that call stopApp expect.
*/
@Override
public void stopApp() {
unref();
}
/**
* {@inheritDoc}
*
* Since THIS is already such an object, it could return itself.
* However, we want the group to know about the number of interfaces
* objects floating around, so, we'll have the group make a new one.
* That way, applications which want to use unref() on interfaces can
* avoid sharing interface objects by using getInterface() as a sort of
* clone with the additional ref-counting semantics.
*
* @return Service An interface object that implements
* this service and nothing more.
*/
@Override
public Service getInterface() {
PeerGroup temp = groupImpl;
if (null == temp) {
throw new IllegalStateException("This Peer Group interface object has been unreferenced and can no longer be used.");
}
return temp.getInterface();
}
/**
* {@inheritDoc}
*
* Returns a weak interface object that refers to this interface
* object rather than to the group directly. The reason for that
* is that we want the owner of this interface object to be able
* to invalidate all weak interface objects made out of this interface
* object, without them keeping a reference to the group object, and
* without necessarily having to terminate the group.
*
* @return PeerGroup A weak interface object that implements
* this group and nothing more.
*/
@Override
public PeerGroup getWeakInterface() {
return new PeerGroupInterface(this);
}
/**
* Can only be called once. After that the reference is no-longer usuable.
*/
@Override
public void unref() {
GenericPeerGroup theGrp;
synchronized (this) {
if (groupImpl == null) {
return;
}
theGrp = (GenericPeerGroup) groupImpl;
groupImpl = null;
}
theGrp.decRefCount();
}
/**
* Service-specific role mapping is implemented here.
**/
/**
* {@inheritDoc}
*/
@Override
public Service lookupService(ID name) throws ServiceNotFoundException {
return lookupService(name, 0);
}
/**
* {@inheritDoc}
*/
@Override
public Service lookupService(ID name, int roleIndex) throws ServiceNotFoundException {
if (roleMap != null) {
ID[] map = (ID[]) roleMap.get(name);
// If there is a map, remap; else, identity is the default for
// role 0 only; the default mapping has only index 0.
if (map != null) {
if (roleIndex < 0 || roleIndex >= map.length) {
throw new ServiceNotFoundException(name + "[" + roleIndex + "]");
}
// We have a translation; look it up directly
return groupImpl.lookupService(map[roleIndex]);
}
}
// No translation; use the name as-is, provided roleIndex is 0.
// Do not call groupImpl.lookupService(name, id); group impls
// should not have to implement it at all.
if (roleIndex != 0) {
throw new ServiceNotFoundException(name + "[" + roleIndex + "]");
}
return groupImpl.lookupService(name);
}
/**
* {@inheritDoc}
*/
@Override
public Iterator getRoleMap(ID name) {
if (roleMap != null) {
ID[] map = (ID[]) roleMap.get(name);
// If there is a map, remap; else, identity is the default for
// role 0 only; the default mapping has only index 0.
if (map != null) {
// return an iterator on it.
return Collections.unmodifiableList(Arrays.asList(map)).iterator();
}
}
// No translation; use the given name in a singleton.
return Collections.singletonList(name).iterator();
}
}