Java tutorial
/* * 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 com.chinamobile.bcbsp.ml; import java.util.StringTokenizer; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.io.Text; import com.chinamobile.bcbsp.Constants; import com.chinamobile.bcbsp.api.RecordParse; import com.chinamobile.bcbsp.api.Vertex; import com.chinamobile.bcbsp.util.BSPJob; /** * RecordParseDefault This class is used to parse a record as a HeadNode object. */ public class RecordParseML extends RecordParse { /**The log of the class.*/ private static final Log LOG = LogFactory.getLog(RecordParseML.class); /**The vertex to be Parse.*/ private Class<? extends Vertex<?, ?, ?>> vertexClass; /** * @param key The key of the vertex * @param value The value of the vertex * @return The vertex of the key and value */ @Override public Vertex recordParse(String key, String value) { Vertex vertex = null; try { vertex = vertexClass.newInstance(); vertex.fromString(key + Constants.KV_SPLIT_FLAG + value); } catch (Exception e) { LOG.error("RecordParse", e); return null; } return vertex; } /** * This method is used to parse a record and obtain VertexID . * @param key The key of the vertex record * @return the vertex id */ @Override public Text getVertexID(Text key) { try { StringTokenizer str = new StringTokenizer(key.toString(), Constants.SPLIT_FLAG); if (str.countTokens() < 1) { return null; } return new Text(str.nextToken()); } catch (Exception e) { return null; } } /** * This method is used to initialize the RecordParseDefault. * @param job The Bsp job. */ @Override public void init(BSPJob job) { //this.vertexClass = (Class<? extends Vertex<?, ?, ?>>) KeyValueVertex.class; this.vertexClass = job.getVertexClass(); } }