/**
* 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.
*/
package org.apache.mahout.cf.taste.example.email;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.mahout.math.VarIntWritable;
import java.io.IOException;
/**
* Assumes the input is in the format created by {@link org.apache.mahout.text.SequenceFilesFromMailArchives}
*/
public final class MsgIdToDictionaryMapper extends Mapper<Text, Text, Text, VarIntWritable> {
@Override
protected void map(Text key, Text value, Context context) throws IOException, InterruptedException {
//message id is in the key: /201008/AANLkTikvVnhNH+Y5AGEwqd2=u0CFv2mCm0ce6E6oBnj1@mail.gmail.com
String keyStr = key.toString();
int idx = keyStr.lastIndexOf('@');//find the last @
if (idx == -1) {
context.getCounter(EmailUtility.Counters.NO_MESSAGE_ID).increment(1);
} else {
//found the @, now find the last slash before the @ and grab everything after that
idx = keyStr.lastIndexOf('/', idx);
String msgId = keyStr.substring(idx + 1);
if (EmailUtility.WHITESPACE.matcher(msgId).matches()) {
context.getCounter(EmailUtility.Counters.NO_MESSAGE_ID).increment(1);
} else {
context.write(new Text(msgId), new VarIntWritable(1));
}
}
}
}