/*
* 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.ambari.view.hive20.client;
import com.beust.jcommander.internal.Lists;
import org.apache.commons.lang.NotImplementedException;
import java.util.Iterator;
import java.util.List;
public class EmptyCursor implements Cursor<Row, ColumnDescription> {
private List<Row> rows = Lists.newArrayList();
private List<ColumnDescription> desc = Lists.newArrayList();
@Override
public boolean isResettable() {
return false;
}
@Override
public void reset() {
}
@Override
public int getOffset() {
return 0;
}
@Override
public List<ColumnDescription> getDescriptions() {
return desc;
}
@Override
public void keepAlive() {
// Do Nothing
}
/**
* Returns an iterator over a set of elements of type T.
*
* @return an Iterator.
*/
@Override
public Iterator<Row> iterator() {
return rows.iterator();
}
/**
* Returns {@code true} if the iteration has more elements.
* (In other words, returns {@code true} if {@link #next} would
* return an element rather than throwing an exception.)
*
* @return {@code true} if the iteration has more elements
*/
@Override
public boolean hasNext() {
return false;
}
/**
* Returns the next element in the iteration.
*
* @return the next element in the iteration
* @throws NotImplementedException if the iteration has no more elements
*/
@Override
public Row next() {
throw new NotImplementedException();
}
/**
* Removes from the underlying collection the last element returned
* by this iterator (optional operation). This method can be called
* only once per call to {@link #next}. The behavior of an iterator
* is unspecified if the underlying collection is modified while the
* iteration is in progress in any way other than by calling this
* method.
*
* @throws UnsupportedOperationException if the {@code remove}
* operation is not supported by this iterator
* @throws IllegalStateException if the {@code next} method has not
* yet been called, or the {@code remove} method has already
* been called after the last call to the {@code next}
* method
*/
@Override
public void remove() {
throw new NotImplementedException();
}
}