Source code

001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.io.storage.util;
020
021import org.apache.reef.exception.evaluator.ServiceRuntimeException;
022import org.apache.reef.io.serialization.Deserializer;
023
024import java.io.DataInputStream;
025import java.io.IOException;
026import java.io.InputStream;
027import java.nio.charset.StandardCharsets;
028import java.util.Iterator;
029
030public class StringDeserializer implements
031    Deserializer<String, InputStream> {
032  @Override
033  public Iterable<String> create(final InputStream arg) {
034    final DataInputStream dis = new DataInputStream(arg);
035    return new Iterable<String>() {
036
037      @Override
038      public Iterator<String> iterator() {
039        return new Iterator<String>() {
040
041          @Override
042          public void remove() {
043            throw new UnsupportedOperationException();
044          }
045
046          @Override
047          public String next() {
048            int len = 0;
049            try {
050              len = dis.readInt();
051              final byte[] b = new byte[len];
052              dis.readFully(b);
053              return new String(b, StandardCharsets.UTF_8);
054            } catch (final IOException e) {
055              throw new ServiceRuntimeException(e);
056            }
057          }
058
059          @Override
060          public boolean hasNext() {
061            throw new UnsupportedOperationException();
062          }
063        };
064      }
065    };
066  }
067}