org.goldenorb.zookeeper.ConnectWatcher.java Source code

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Here is the source code for org.goldenorb.zookeeper.ConnectWatcher.java

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/**
 * Licensed to Ravel, Inc. under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  Ravel, Inc. 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.goldenorb.zookeeper;

import java.io.IOException;
import java.util.concurrent.CountDownLatch;

import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.Watcher.Event.KeeperState;

/**
 * This class defines a ConnectWatcher, which is used to place watches for member nodes within the ZooKeeper
 * substructure.
 * 
 */
public class ConnectWatcher implements Watcher {

    private static final int SESSION_TIMEOUT = 10000;
    private CountDownLatch connectedSignal = new CountDownLatch(1);

    /**
     * This method connects to a running ZooKeeper.
     * 
     * @param hosts
     *          - String containing a comma separated list of host:port pairs, each corresponding to a ZooKeeper
     *          server.
     * @returns ZooKeeper
     */
    public ZooKeeper connect(String hosts) throws IOException, InterruptedException {
        ZooKeeper _zk = new ZooKeeper(hosts, SESSION_TIMEOUT, this);
        connectedSignal.await();
        return _zk;
    }

    /**
     * This method executes its content given a Watcher event.
     * 
     * @param event
     *          - WatchedEvent
     */
    public void process(WatchedEvent event) {
        if (event.getState() == KeeperState.SyncConnected) {
            connectedSignal.countDown();
        }
    }
}