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.ignite.internal.processors.hadoop.impl; import com.google.common.base.Joiner; import java.io.BufferedReader; import java.io.InputStream; import java.io.InputStreamReader; import java.io.PrintWriter; import java.util.ArrayList; import java.util.Collections; import java.util.List; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.IntWritable; import org.apache.hadoop.io.SequenceFile; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; import org.apache.ignite.igfs.IgfsPath; import org.apache.ignite.internal.processors.igfs.IgfsEx; /** * Abstract class for tests based on WordCount test job. */ public abstract class HadoopAbstractWordCountTest extends HadoopAbstractSelfTest { /** Input path. */ protected static final String PATH_INPUT = "/input"; /** Output path. */ protected static final String PATH_OUTPUT = "/output"; /** IGFS instance. */ protected IgfsEx igfs; /** {@inheritDoc} */ @Override protected void beforeTestsStarted0() throws Exception { Configuration cfg = new Configuration(); setupFileSystems(cfg); // Init cache by correct LocalFileSystem implementation FileSystem.getLocal(cfg); } /** {@inheritDoc} */ @Override protected void beforeTest() throws Exception { super.beforeTest(); igfs = (IgfsEx) startGrids(gridCount()).fileSystem(igfsName); } /** {@inheritDoc} */ @Override protected void afterTest() throws Exception { stopAllGrids(true); } /** {@inheritDoc} */ @Override protected boolean igfsEnabled() { return true; } /** {@inheritDoc} */ @Override protected int gridCount() { return 1; } /** * Generates test file. * * @param path File name. * @param wordCounts Words and counts. * @throws Exception If failed. */ protected void generateTestFile(String path, Object... wordCounts) throws Exception { List<String> wordsArr = new ArrayList<>(); //Generating for (int i = 0; i < wordCounts.length; i += 2) { String word = (String) wordCounts[i]; int cnt = (Integer) wordCounts[i + 1]; while (cnt-- > 0) wordsArr.add(word); } //Shuffling for (int i = 0; i < wordsArr.size(); i++) { int j = (int) (Math.random() * wordsArr.size()); Collections.swap(wordsArr, i, j); } //Input file preparing PrintWriter testInputFileWriter = new PrintWriter(igfs.create(new IgfsPath(path), true)); int j = 0; while (j < wordsArr.size()) { int i = 5 + (int) (Math.random() * 5); List<String> subList = wordsArr.subList(j, Math.min(j + i, wordsArr.size())); j += i; testInputFileWriter.println(Joiner.on(' ').join(subList)); } testInputFileWriter.close(); } /** * Read w/o decoding (default). * * @param fileName The file. * @return The file contents, human-readable. * @throws Exception On error. */ protected String readAndSortFile(String fileName) throws Exception { return readAndSortFile(fileName, null); } /** * Reads whole text file into String. * * @param fileName Name of the file to read. * @return Content of the file as String value. * @throws Exception If could not read the file. */ protected String readAndSortFile(String fileName, Configuration conf) throws Exception { final List<String> list = new ArrayList<>(); final boolean snappyDecode = conf != null && conf.getBoolean(FileOutputFormat.COMPRESS, false); if (snappyDecode) { try (SequenceFile.Reader reader = new SequenceFile.Reader(conf, SequenceFile.Reader.file(new Path(fileName)))) { Text key = new Text(); IntWritable val = new IntWritable(); while (reader.next(key, val)) list.add(key + "\t" + val); } } else { try (InputStream is0 = igfs.open(new IgfsPath(fileName))) { BufferedReader reader = new BufferedReader(new InputStreamReader(is0)); String line; while ((line = reader.readLine()) != null) list.add(line); } } Collections.sort(list); return Joiner.on('\n').join(list) + "\n"; } }