org.apache.camel.component.zookeeper.SequenceComparator Maven / Gradle / Ivy
/**
* 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.camel.component.zookeeper;
import org.apache.zookeeper.CreateMode;
/**
* Nodes created with any of Sequential {@link CreateMode}s will have a 10
* character sequence attached to their node names.
* SequenceComparator is a Natural comparator used to compare lists
* of objects with these appended sequences.
*/
public class SequenceComparator extends NaturalSortComparator {
public static final int ZOOKEEPER_SEQUENCE_LENGTH = 10;
@Override
public int compare(CharSequence sequencedNode, CharSequence otherSequencedNode) {
if (sequencedNode == null && otherSequencedNode == null) {
return 0;
}
if (sequencedNode != null && otherSequencedNode == null) {
return 1;
}
if (sequencedNode == null && otherSequencedNode != null) {
return -1;
}
return super.compare(getZooKeeperSequenceNumber(sequencedNode), getZooKeeperSequenceNumber(otherSequencedNode));
}
private CharSequence getZooKeeperSequenceNumber(CharSequence sequencedNodeName) {
int len = sequencedNodeName.length();
return sequencedNodeName.subSequence(len - ZOOKEEPER_SEQUENCE_LENGTH, len);
}
}