StdInOpener.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.io;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;

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;


/**
 * Helper class to open stdin
 *
 * @author Markus Michael Geipel
 *
 */
@Description("Opens a file.")
@In(String.class)
@Out(java.io.Reader.class)
public final class StdInOpener extends DefaultObjectPipe<Object, ObjectReceiver<java.io.Reader>> {

	@Override
	public void process(final Object notUsed) {
		if (notUsed == null) {
			BufferedReader stdin;
			try {
				stdin = new BufferedReader(new InputStreamReader(System.in, "UTF-8"));
			} catch (UnsupportedEncodingException e) {
				throw new IllegalStateException("UTF-8 not supported", e);
			}
			getReceiver().process(stdin);
		} else {
			throw new IllegalArgumentException("Parameter not used. Must be null");
		}
	}
}