MultiFormatReader.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.test.reader;

import org.culturegraph.mf.framework.StreamReceiver;


/**
 * Dynamically instantiated a reader for a specific data format. This module
 * allows to select a concrete reader only at runtime.
 *
 * @author Markus Michael Geipel
 */
public final class MultiFormatReader implements Reader {

	private static final ReaderFactory READER_FACTORY = new ReaderFactory();

	private StreamReceiver downstreamReceiver;
	private Reader currentReader;

	public MultiFormatReader(final String format) {
		setFormat(format);
	}

	public void setFormat(final String format) {
		if(!READER_FACTORY.containsKey(format)){
			throw new IllegalArgumentException("Format '" + format +
					"' not regognized");
		}
		currentReader = READER_FACTORY.newInstance(format);
		currentReader.setReceiver(downstreamReceiver);
	}

	@Override
	public <R extends StreamReceiver> R setReceiver(final R streamReceiver) {
		downstreamReceiver = streamReceiver;
		return currentReader.setReceiver(streamReceiver);
	}

	@Override
	public void process(final java.io.Reader reader) {
		currentReader.process(reader);
	}

	@Override
	public void resetStream() {
		currentReader.resetStream();
	}

	@Override
	public void closeStream() {
		currentReader.closeStream();
	}

}