| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreemnets. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.opennlp.ml.model; |
| |
| import java.io.IOException; |
| import java.io.UnsupportedEncodingException; |
| import java.math.BigInteger; |
| import java.security.MessageDigest; |
| import java.security.NoSuchAlgorithmException; |
| |
| import org.apache.opennlp.ml.model.Event; |
| import org.apache.opennlp.ml.model.EventStream; |
| |
| public class HashSumEventStream implements EventStream { |
| |
| private final EventStream eventStream; |
| |
| private MessageDigest digest; |
| |
| public HashSumEventStream(EventStream eventStream) { |
| this.eventStream = eventStream; |
| |
| try { |
| digest = MessageDigest.getInstance("MD5"); |
| } catch (NoSuchAlgorithmException e) { |
| // should never happen, does all java runtimes have md5 ?! |
| throw new IllegalStateException(e); |
| } |
| } |
| |
| public boolean hasNext() throws IOException { |
| return eventStream.hasNext(); |
| } |
| |
| public Event next() throws IOException { |
| |
| Event event = eventStream.next(); |
| |
| try { |
| digest.update(event.toString().getBytes("UTF-8")); |
| } |
| catch (UnsupportedEncodingException e) { |
| throw new IllegalStateException("UTF-8 encoding is not available!"); |
| } |
| |
| return event; |
| } |
| |
| /** |
| * Calculates the hash sum of the stream. The method must be |
| * called after the stream is completely consumed. |
| * |
| * @return the hash sum |
| * @throws IllegalStateException if the stream is not consumed completely, |
| * completely means that hasNext() returns false |
| */ |
| public BigInteger calculateHashSum() { |
| |
| // if (hasNext()) |
| // throw new IllegalStateException("stream must be consumed completely!"); |
| |
| return new BigInteger(1, digest.digest()); |
| } |
| |
| public void remove() { |
| } |
| } |