diff options
Diffstat (limited to 'java/broker-core/src/main/java/org/apache/qpid/server/subscription/AbstractSubscriptionTarget.java')
-rw-r--r-- | java/broker-core/src/main/java/org/apache/qpid/server/subscription/AbstractSubscriptionTarget.java | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/java/broker-core/src/main/java/org/apache/qpid/server/subscription/AbstractSubscriptionTarget.java b/java/broker-core/src/main/java/org/apache/qpid/server/subscription/AbstractSubscriptionTarget.java new file mode 100644 index 0000000000..4d9550907e --- /dev/null +++ b/java/broker-core/src/main/java/org/apache/qpid/server/subscription/AbstractSubscriptionTarget.java @@ -0,0 +1,73 @@ +/* + * + * 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 org.apache.qpid.server.subscription; + +import org.apache.qpid.server.util.StateChangeListener; + +import java.util.concurrent.atomic.AtomicReference; + +public abstract class AbstractSubscriptionTarget implements SubscriptionTarget +{ + + private final AtomicReference<State> _state; + private final AtomicReference<StateChangeListener<SubscriptionTarget, State>> _stateListener = + new AtomicReference<StateChangeListener<SubscriptionTarget, State>>(); + + protected AbstractSubscriptionTarget(final State initialState) + { + _state = new AtomicReference<State>(initialState); + } + + + public final State getState() + { + return _state.get(); + } + + protected final boolean updateState(State from, State to) + { + if(_state.compareAndSet(from, to)) + { + StateChangeListener<SubscriptionTarget, State> listener = _stateListener.get(); + if(listener != null) + { + listener.stateChanged(this, from, to); + } + return true; + } + else + { + return false; + } + } + + + public final void setStateListener(StateChangeListener<SubscriptionTarget, State> listener) + { + _stateListener.set(listener); + } + + public final StateChangeListener<SubscriptionTarget, State> getStateListener() + { + return _stateListener.get(); + } + +} |