org.apache.kafka.common.utils.CircularIterator 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.kafka.common.utils;
import java.util.Iterator;
import java.util.List;
public class CircularIterator implements Iterator {
int i = 0;
private List list;
public CircularIterator(List list) {
if (list.isEmpty()) {
throw new IllegalArgumentException("CircularIterator can only be used on non-empty lists");
}
this.list = list;
}
@Override
public boolean hasNext() {
return true;
}
@Override
public T next() {
T next = list.get(i);
i = (i + 1) % list.size();
return next;
}
public T peek() {
return list.get(i);
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
}