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 org.apache.bigtop.bigpetstore.generator; import java.io.DataInput; import java.io.DataOutput; import java.io.IOException; import org.apache.bigtop.bigpetstore.generator.util.State; import org.apache.commons.lang3.Range; import org.apache.hadoop.io.Writable; import org.apache.hadoop.mapreduce.InputSplit; /** * What does an `InputSplit` actually do? From the Javadocs, it looks like ... * absolutely nothing. * * Note: for some reason, you *have* to implement Writable, even if your methods * do nothing, or you will got strange and un-debuggable null pointer * exceptions. */ public class PetStoreTransactionInputSplit extends InputSplit implements Writable { public PetStoreTransactionInputSplit() { } public int records; public State state; public Range<Long> customerIdRange; public PetStoreTransactionInputSplit(int records, Range<Long> customerIdRange, State state) { this.records = records; this.state = state; this.customerIdRange = customerIdRange; } public void readFields(DataInput dataInputStream) throws IOException { records = dataInputStream.readInt(); state = State.valueOf(dataInputStream.readUTF()); customerIdRange = Range.between(dataInputStream.readLong(), dataInputStream.readLong()); } public void write(DataOutput dataOutputStream) throws IOException { dataOutputStream.writeInt(records); dataOutputStream.writeUTF(state.name()); dataOutputStream.writeLong(customerIdRange.getMinimum()); dataOutputStream.writeLong(customerIdRange.getMaximum()); } @Override public String[] getLocations() throws IOException, InterruptedException { return new String[] {}; } @Override public long getLength() throws IOException, InterruptedException { return records; } }