| /* |
| * 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.util; |
| |
| import java.io.DataInput; |
| import java.io.IOException; |
| |
| import org.apache.hadoop.conf.Configurable; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.io.GenericWritable; |
| import org.apache.hadoop.io.Writable; |
| |
| /** |
| * A generic Writable wrapper that can inject Configuration to |
| * {@link Configurable}s |
| */ |
| public abstract class GenericWritableConfigurable extends GenericWritable |
| implements Configurable { |
| |
| private Configuration conf; |
| |
| public Configuration getConf() { |
| return conf; |
| } |
| |
| public void setConf(Configuration conf) { |
| this.conf = conf; |
| } |
| |
| @Override |
| public void readFields(DataInput in) throws IOException { |
| byte type = in.readByte(); |
| Class<?> clazz = getTypes()[type]; |
| try { |
| set((Writable) clazz.getConstructor().newInstance()); |
| } catch (Exception e) { |
| e.printStackTrace(); |
| throw new IOException("Cannot initialize the class: " + clazz); |
| } |
| Writable w = get(); |
| if (w instanceof Configurable) |
| ((Configurable) w).setConf(conf); |
| w.readFields(in); |
| } |
| |
| } |