DuplicateObjectFilter.java

/*
 * Copyright 2013, 2014 Deutsche Nationalbibliothek
 *
 * Licensed 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.culturegraph.mf.mangling;

import org.culturegraph.mf.framework.FluxCommand;
import org.culturegraph.mf.framework.ObjectReceiver;
import org.culturegraph.mf.framework.annotations.Description;
import org.culturegraph.mf.framework.annotations.In;
import org.culturegraph.mf.framework.annotations.Out;
import org.culturegraph.mf.framework.helpers.DefaultObjectPipe;

/**
 * Filters consecutive duplicated data objects.
 *
 * @param <T> object type
 *
 * @author Alexander Haffner
 *
 */
@Description("Filters consecutive duplicated data objects.")
@In(Object.class)
@Out(Object.class)
@FluxCommand("filter-duplicate-objects")
public final class DuplicateObjectFilter<T> extends
		DefaultObjectPipe<T, ObjectReceiver<T>> {

	private T lastObj;

	@Override
	public void process(final T obj) {
		if (!obj.equals(lastObj)) {
			lastObj = obj;
			getReceiver().process(obj);
		}
	}

	@Override
	protected void onResetStream() {
		lastObj = null;
	}

}