| /* |
| * 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.nutch.metadata; |
| |
| import java.io.DataInput; |
| import java.io.DataOutput; |
| import java.io.IOException; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.io.Writable; |
| import org.apache.nutch.crawl.NutchWritable; |
| |
| /** |
| * This is a simple decorator that adds metadata to any Writable-s that can be |
| * serialized by <tt>NutchWritable</tt>. This is useful when data needs to be |
| * temporarily enriched during processing, but this temporary metadata doesn't |
| * need to be permanently stored after the job is done. |
| * |
| * @author Andrzej Bialecki |
| */ |
| public class MetaWrapper extends NutchWritable { |
| private Metadata metadata; |
| |
| public MetaWrapper() { |
| super(); |
| metadata = new Metadata(); |
| } |
| |
| public MetaWrapper(Writable instance, Configuration conf) { |
| super(instance); |
| metadata = new Metadata(); |
| setConf(conf); |
| } |
| |
| public MetaWrapper(Metadata metadata, Writable instance, Configuration conf) { |
| super(instance); |
| if (metadata == null) |
| metadata = new Metadata(); |
| this.metadata = metadata; |
| setConf(conf); |
| } |
| |
| /** |
| * Get all metadata. |
| */ |
| public Metadata getMetadata() { |
| return metadata; |
| } |
| |
| /** |
| * Add metadata. See {@link Metadata#add(String, String)} for more |
| * information. |
| * |
| * @param name |
| * metadata name |
| * @param value |
| * metadata value |
| */ |
| public void addMeta(String name, String value) { |
| metadata.add(name, value); |
| } |
| |
| /** |
| * Set metadata. See {@link Metadata#set(String, String)} for more |
| * information. |
| * |
| * @param name |
| * @param value |
| */ |
| public void setMeta(String name, String value) { |
| metadata.set(name, value); |
| } |
| |
| /** |
| * Get metadata. See {@link Metadata#get(String)} for more information. |
| * |
| * @param name |
| * @return metadata value |
| */ |
| public String getMeta(String name) { |
| return metadata.get(name); |
| } |
| |
| /** |
| * Get multiple metadata. See {@link Metadata#getValues(String)} for more |
| * information. |
| * |
| * @param name |
| * @return multiple values |
| */ |
| public String[] getMetaValues(String name) { |
| return metadata.getValues(name); |
| } |
| |
| public void readFields(DataInput in) throws IOException { |
| super.readFields(in); |
| metadata = new Metadata(); |
| metadata.readFields(in); |
| } |
| |
| public void write(DataOutput out) throws IOException { |
| super.write(out); |
| metadata.write(out); |
| } |
| } |