package com.digitalpebble.behemoth.mahout;
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. 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.
*/
import java.io.IOException;
import java.util.Iterator;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.mahout.common.StringTuple;
import com.digitalpebble.behemoth.Annotation;
import com.digitalpebble.behemoth.BehemothDocument;
/**
* Extracts tokens from a Behemoth document and outputs them in a StringTuple
*/
public class BehemothTokenizerMapper extends
Mapper<Text, BehemothDocument, Text, StringTuple> {
private String tokenType;
private String tokenFeature;
@Override
protected void map(Text key, BehemothDocument value, Context context)
throws IOException, InterruptedException {
StringTuple document = new StringTuple();
Iterator<Annotation> iter = value.getAnnotations().iterator();
while (iter.hasNext()) {
Annotation annot = iter.next();
// check the type
if (!annot.getType().equals(tokenType))
continue;
java.util.Map<String, String> features = annot.getFeatures();
if (features == null)
continue;
String featureValue = null;
// no feature? use the underlying text
if (tokenFeature.equals("")) {
featureValue = value.getText().substring(
(int) annot.getStart(), (int) annot.getEnd());
} else
featureValue = features.get(tokenFeature);
if (featureValue == null)
continue;
document.add(featureValue);
}
context.write(key, document);
}
@Override
protected void setup(Context context) throws IOException,
InterruptedException {
super.setup(context);
this.tokenType = context.getConfiguration().get(
BehemothDocumentProcessor.TOKEN_TYPE);
this.tokenFeature = context.getConfiguration().get(
BehemothDocumentProcessor.FEATURE_NAME, "");
}
}