Java tutorial
/* * Copyright 2011 Mozilla Foundation * * 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.mozilla.grouperfish.transforms.coclustering.text; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.HashMap; import java.util.HashSet; import java.util.Map; import java.util.Set; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FileStatus; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class Dictionary { private static final Logger LOG = LoggerFactory.getLogger(Dictionary.class); public static Set<String> loadDictionary(Path dictionaryPath) throws IOException { Set<String> dictionary = null; FileSystem fs = null; try { fs = FileSystem.get(dictionaryPath.toUri(), new Configuration()); dictionary = loadDictionary(fs, dictionaryPath); } finally { if (fs != null) { fs.close(); } } return dictionary; } public static Set<String> loadDictionary(FileSystem fs, Path dictionaryPath) throws IOException { Set<String> dictionary = null; if (dictionaryPath != null) { dictionary = new HashSet<String>(); for (FileStatus status : fs.listStatus(dictionaryPath)) { if (!status.isDir()) { BufferedReader reader = null; try { reader = new BufferedReader(new InputStreamReader(fs.open(status.getPath()))); String word = null; while ((word = reader.readLine()) != null) { dictionary.add(word.trim()); } } finally { if (reader != null) { reader.close(); } } } } LOG.info("Loaded dictionary with size: " + dictionary.size()); } return dictionary; } public static Map<String, Integer> loadFeatureIndex(Path dictionaryPath) throws IOException { Map<String, Integer> featureIndex = null; FileSystem fs = null; try { fs = FileSystem.get(dictionaryPath.toUri(), new Configuration()); featureIndex = loadFeatureIndex(fs, dictionaryPath); } finally { if (fs != null) { fs.close(); } } return featureIndex; } public static Map<String, Integer> loadFeatureIndex(FileSystem fs, Path dictionaryPath) throws IOException { Map<String, Integer> featureIndex = null; if (dictionaryPath != null) { featureIndex = new HashMap<String, Integer>(); int idx = 0; for (FileStatus status : fs.listStatus(dictionaryPath)) { if (!status.isDir()) { BufferedReader reader = null; try { reader = new BufferedReader(new InputStreamReader(fs.open(status.getPath()))); String word = null; while ((word = reader.readLine()) != null) { featureIndex.put(word.trim(), idx++); } } finally { if (reader != null) { reader.close(); } } } } LOG.info("Loaded dictionary with size: " + featureIndex.size()); } return featureIndex; } public static Map<Integer, String> loadInvertedFeatureIndex(Path dictionaryPath) throws IOException { Map<Integer, String> featureIndex = null; FileSystem fs = null; try { fs = FileSystem.get(dictionaryPath.toUri(), new Configuration()); featureIndex = loadInvertedFeatureIndex(fs, dictionaryPath); } finally { if (fs != null) { fs.close(); } } return featureIndex; } public static Map<Integer, String> loadInvertedIndexWithKeys(Path dictionaryPath) throws IOException { Map<Integer, String> index = null; FileSystem fs = null; try { fs = FileSystem.get(dictionaryPath.toUri(), new Configuration()); index = loadInvertedIndexWithKeys(fs, dictionaryPath); } finally { if (fs != null) { fs.close(); } } return index; } public static Map<Integer, String> loadInvertedIndexWithKeys(FileSystem fs, Path dictionaryPath) throws IOException { Map<Integer, String> index = null; if (dictionaryPath != null) { index = new HashMap<Integer, String>(); for (FileStatus status : fs.listStatus(dictionaryPath)) { if (!status.isDir()) { BufferedReader reader = null; try { reader = new BufferedReader(new InputStreamReader(fs.open(status.getPath()))); String line = null; while ((line = reader.readLine()) != null) { String[] pair = line.split("\t"); index.put(Integer.parseInt(pair[0]), pair[1].trim()); } } finally { if (reader != null) { reader.close(); } } } } LOG.info("Loaded dictionary with size: " + index.size()); } return index; } public static Map<Integer, String> loadInvertedFeatureIndex(FileSystem fs, Path dictionaryPath) throws IOException { Map<Integer, String> featureIndex = null; if (dictionaryPath != null) { featureIndex = new HashMap<Integer, String>(); int idx = 0; for (FileStatus status : fs.listStatus(dictionaryPath)) { if (!status.isDir()) { BufferedReader reader = null; try { reader = new BufferedReader(new InputStreamReader(fs.open(status.getPath()))); String word = null; while ((word = reader.readLine()) != null) { featureIndex.put(idx++, word.trim()); } } finally { if (reader != null) { reader.close(); } } } } LOG.info("Loaded dictionary with size: " + featureIndex.size()); } return featureIndex; } }