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, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019 package org.apache.hadoop.mapred.lib;
020
021 import java.io.IOException;
022
023 import org.apache.hadoop.classification.InterfaceAudience;
024 import org.apache.hadoop.classification.InterfaceStability;
025 import org.apache.hadoop.fs.FileSystem;
026 import org.apache.hadoop.mapred.JobConf;
027 import org.apache.hadoop.mapred.OutputFormat;
028 import org.apache.hadoop.mapred.RecordWriter;
029 import org.apache.hadoop.mapred.Reporter;
030 import org.apache.hadoop.util.Progressable;
031
032 /**
033 * FilterOutputFormat is a convenience class that wraps OutputFormat.
034 */
035 @InterfaceAudience.Public
036 @InterfaceStability.Stable
037 public class FilterOutputFormat<K, V> implements OutputFormat<K, V> {
038
039 protected OutputFormat<K,V> baseOut;
040
041 public FilterOutputFormat () {
042 this.baseOut = null;
043 }
044
045 /**
046 * Create a FilterOutputFormat based on the supplied output format.
047 * @param out the underlying OutputFormat
048 */
049 public FilterOutputFormat (OutputFormat<K,V> out) {
050 this.baseOut = out;
051 }
052
053 public RecordWriter<K, V> getRecordWriter(FileSystem ignored, JobConf job,
054 String name, Progressable progress) throws IOException {
055 return getBaseOut().getRecordWriter(ignored, job, name, progress);
056 }
057
058 public void checkOutputSpecs(FileSystem ignored, JobConf job)
059 throws IOException {
060 getBaseOut().checkOutputSpecs(ignored, job);
061 }
062
063 private OutputFormat<K,V> getBaseOut() throws IOException {
064 if (baseOut == null) {
065 throw new IOException("Outputformat not set for FilterOutputFormat");
066 }
067 return baseOut;
068 }
069
070 /**
071 * <code>FilterRecordWriter</code> is a convenience wrapper
072 * class that implements {@link RecordWriter}.
073 */
074
075 public static class FilterRecordWriter<K,V> implements RecordWriter<K,V> {
076
077 protected RecordWriter<K,V> rawWriter = null;
078
079 public FilterRecordWriter() throws IOException {
080 rawWriter = null;
081 }
082
083 public FilterRecordWriter(RecordWriter<K,V> rawWriter) throws IOException {
084 this.rawWriter = rawWriter;
085 }
086
087 public void close(Reporter reporter) throws IOException {
088 getRawWriter().close(reporter);
089 }
090
091 public void write(K key, V value) throws IOException {
092 getRawWriter().write(key, value);
093 }
094
095 private RecordWriter<K,V> getRawWriter() throws IOException {
096 if (rawWriter == null) {
097 throw new IOException ("Record Writer not set for FilterRecordWriter");
098 }
099 return rawWriter;
100 }
101 }
102
103 }