import org.I0Itec.zkclient.exception.ZkBadVersionException; //导入依赖的package包/类
/**
 * Updates data of an existing znode. The current content of the znode is passed to the {@link DataUpdater} that is
 * passed into this method, which returns the new content. The new content is only written back to ZooKeeper if
 * nobody has modified the given znode in between. If a concurrent change has been detected the new data of the
 * znode is passed to the updater once again until the new contents can be successfully written back to ZooKeeper.
 *
 * @param <T>
 * @param path
 *            The path of the znode.
 * @param updater
 *            Updater that creates the new contents.
 */
@SuppressWarnings("unchecked") public <T extends Object> void updateDataSerialized(String path,
    DataUpdater<T> updater) {
  Stat stat = new Stat();
  boolean retry;
  do {
    retry = false;
    try {
      T oldData = (T) readData(path, stat);
      T newData = updater.update(oldData);
      writeData(path, newData, stat.getVersion());
    } catch (ZkBadVersionException e) {
      retry = true;
    }
  } while (retry);
}
 

import org.I0Itec.zkclient.exception.ZkBadVersionException; //导入依赖的package包/类
/**
 * Updates data of an existing znode. The current content of the znode is passed to the {@link DataUpdater} that is
 * passed into this method, which returns the new content. The new content is only written back to ZooKeeper if
 * nobody has modified the given znode in between. If a concurrent change has been detected the new data of the
 * znode is passed to the updater once again until the new contents can be successfully written back to ZooKeeper.
 * 
 * @param <T>
 * @param path The path of the znode.
 * @param updater Updater that creates the new contents.
 */
public <T extends Object> void updateDataSerialized(String path, DataUpdater<T> updater) {
    Stat stat = new Stat();
    boolean retry;
    do {
        retry = false;
        try {
            T oldData = (T) readData(path, stat);
            T newData = updater.update(oldData);
            writeData(path, newData, stat.getVersion());
        } catch (ZkBadVersionException e) {
            retry = true;
        }
    } while (retry);
}
 

import org.I0Itec.zkclient.exception.ZkBadVersionException; //导入依赖的package包/类
public static boolean setOfflineSegmentZKMetadata(ZkHelixPropertyStore<ZNRecord> propertyStore,
    OfflineSegmentZKMetadata offlineSegmentZKMetadata, int expectedVersion) {
  // NOTE: Helix will throw ZkBadVersionException if version does not match
  try {
    return propertyStore.set(constructPropertyStorePathForSegment(
        TableNameBuilder.OFFLINE.tableNameWithType(offlineSegmentZKMetadata.getTableName()),
        offlineSegmentZKMetadata.getSegmentName()), offlineSegmentZKMetadata.toZNRecord(), expectedVersion,
        AccessOption.PERSISTENT);
  } catch (ZkBadVersionException e) {
    return false;
  }
}