| /** |
| * 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.sqoop.mapreduce; |
| |
| import java.io.IOException; |
| import java.util.Map; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.mapreduce.InputSplit; |
| import org.apache.hadoop.mapreduce.Mapper; |
| import org.apache.hadoop.mapreduce.lib.input.FileSplit; |
| import com.cloudera.sqoop.lib.SqoopRecord; |
| |
| /** |
| * Given a set of SqoopRecord instances which are from a "new" dataset |
| * or an "old" dataset, extract a key column from the record and tag |
| * each record with a bit specifying whether it is a new or old record. |
| */ |
| public class MergeMapperBase<INKEY, INVAL> |
| extends Mapper<INKEY, INVAL, Text, MergeRecord> { |
| |
| public static final Log LOG = LogFactory.getLog( |
| MergeMapperBase.class.getName()); |
| |
| private String keyColName; // name of the key column. |
| private boolean isNew; // true if this split is from the new dataset. |
| |
| @Override |
| protected void setup(Context context) |
| throws IOException, InterruptedException { |
| Configuration conf = context.getConfiguration(); |
| keyColName = conf.get(MergeJob.MERGE_KEY_COL_KEY); |
| |
| InputSplit is = context.getInputSplit(); |
| FileSplit fs = (FileSplit) is; |
| Path splitPath = fs.getPath(); |
| |
| if (splitPath.toString().startsWith( |
| conf.get(MergeJob.MERGE_NEW_PATH_KEY))) { |
| this.isNew = true; |
| } else if (splitPath.toString().startsWith( |
| conf.get(MergeJob.MERGE_OLD_PATH_KEY))) { |
| this.isNew = false; |
| } else { |
| throw new IOException("File " + splitPath + " is not under new path " |
| + conf.get(MergeJob.MERGE_NEW_PATH_KEY) + " or old path " |
| + conf.get(MergeJob.MERGE_OLD_PATH_KEY)); |
| } |
| } |
| |
| protected void processRecord(SqoopRecord r, Context c) |
| throws IOException, InterruptedException { |
| MergeRecord mr = new MergeRecord(r, isNew); |
| Map<String, Object> fieldMap = r.getFieldMap(); |
| if (null == fieldMap) { |
| throw new IOException("No field map in record " + r); |
| } |
| Object keyObj = fieldMap.get(keyColName); |
| if (null == keyObj) { |
| throw new IOException("Cannot join values on null key. " |
| + "Did you specify a key column that exists?"); |
| } else { |
| c.write(new Text(keyObj.toString()), mr); |
| } |
| } |
| } |