StringDecoder.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.strings;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

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;

/**
 * Splits a {@link String} into several {@link String}s, either by extracting
 * parts that match a regexp or by splitting by a regexp.
 *
 * @author Markus M Geipel
 */
@Description("Splits a String into several Strings, either by extracting parts that match a regexp or by splitting by a regexp.")
@In(String.class)
@Out(String.class)
@FluxCommand("decode-string")
public final class StringDecoder extends DefaultObjectPipe<String, ObjectReceiver<String>> {

	/**
	 * determines whether string is split by the regexp or parts matching the
	 * regexp are extracted
	 *
	 */
	public enum Mode {
		SPLIT, EXTRACT
	}

	private Mode mode = Mode.SPLIT;

	private final Pattern pattern;

	public StringDecoder(final String pattern) {
		this.pattern = Pattern.compile(pattern);
	}

	public void setMode(final Mode mode) {
		this.mode = mode;
	}

	@Override
	public void process(final String obj) {
		assert !isClosed();
		assert null != obj;

		final ObjectReceiver<String> receiver = getReceiver();
		if (mode == Mode.SPLIT) {
			for (String part : pattern.split(obj)) {
				receiver.process(part);
			}
		} else {
			final Matcher matcher = pattern.matcher(obj);
			while (matcher.find()) {
				receiver.process(matcher.group());
			}
		}
	}
}