Java tutorial
/* * Copyright (c) 2012 Fabian Hirschmann <fabian@hirschmann.email> * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package com.github.fhirschmann.clozegen.lib.multiset; import static com.google.common.base.Preconditions.checkNotNull; import java.io.IOException; import java.net.URISyntaxException; import java.net.URL; import java.nio.charset.Charset; import java.util.List; import com.google.common.base.Charsets; import com.google.common.collect.LinkedHashMultiset; import com.google.common.collect.Multiset; import com.google.common.io.Resources; /** * Utility class for parsing frequencies from plain-text files. * * @author Fabian Hirschmann <fabian@hirschmann.email> */ public final class ReadMultisets { /** Constructor in utility class should not be called. */ private ReadMultisets() { } /** * Parses frequencies from a URL. The subject and the count for a subject * need to be delimited by {@code \t} with the count on the right-hand * side. * * <p>For example, assuming your frequency file contains the following lines: * <pre> * one of the 200 * because of the 100 * members of the 50 * </pre> * Then getting the count of "because of the" will yield 100. * * @param url the URL to the file to parse * @param charset the charset of the file * @return the parsed frequencies * @throws IOException on errors reading from the file */ public static Multiset<String> parseMultiset(final URL url, final Charset charset) throws IOException { final Multiset<String> multiset = LinkedHashMultiset.create(); final List<String> lines = Resources.readLines(checkNotNull(url), charset); for (String line : lines) { final String[] tokens = line.split("\t"); multiset.add(tokens[0], Integer.parseInt(tokens[1])); } return multiset; } /** * Parses UTF-8 encoded frequencies from a URL. The subject and the count for a * subject need to be delimited by {@code \t} with the count on the right-hand * side. * * <p>For example, assuming your frequency file contains the following lines: * <pre> * one of the 200 * because of the 100 * members of the 50 * </pre> * Then getting the count of "because of the" will yield 100. * * @param url the URL to the file to parse * @return the parsed frequencies * @throws IOException on errors reading from the file */ public static Multiset<String> parseMultiset(final URL url) throws IOException { return parseMultiset(url, Charsets.UTF_8); } /** * Parses conditional frequencies from a URL. The subject and the count for a subject * need to be delimited by {@code \t} with the count on the right-hand side. * * <p>Additionally, the remaining words on the left-hand side are split using the * whitespace as delimiter. The {@code key} parameter identifies the condition * by which the rest of the word sequence (with the key itself removed) is identified * by. * * <p>For example, assuming your frequency file contains the following lines: * <pre> * one of 200 * because of 100 * members of 50 * </pre> * Then selecting {@code 0} as key will yield a count of 100 when * looking up "of" given the the key (condition) is "because". * * @param url the URL to the file to parse * @param key the key to identify the word sequence by * @param charset the charset of the file * @return the parsed frequencies * @throws IOException on errors reading from the file * @throws URISyntaxException on errors during URI conversion */ public static MapMultiset<String, String> parseMapMultiset(final URL url, final int key, final Charset charset) throws IOException, URISyntaxException { final MapMultiset<String, String> mms = MapMultiset.create(); final List<String> lines = Resources.readLines(checkNotNull(url), charset); for (String line : lines) { final String[] tokens = line.split("\t"); final String[] ngram = tokens[0].split(" "); StringBuilder sb = new StringBuilder(); for (int i = 0; i < ngram.length; i++) { if (i != key) { sb.append(ngram[i]); } } mms.add(ngram[key], sb.toString(), Integer.parseInt(tokens[1])); } return mms; } /** * Parses UTF-8 encoded conditional frequencies from a URL. The subject and the * count for a subject need to be delimited by {@code \t} with the count on the * right-hand side. * * <p>Additionally, the remaining words on the left-hand side are split using the * whitespace as delimiter. The {@code key} parameter identifies the condition * by which the rest of the word sequence (with the key itself removed) is identified * by. * * <p>For example, assuming your frequency file contains the following lines: * <pre> * one of 200 * because of 100 * members of 50 * </pre> * Then selecting {@code 0} as key will yield a count of 100 when * looking up "of" given the the key (condition) is "because". * * @param url the URL to the file to parse * @param key the key to identify the word sequence by * @return the parsed frequencies * @throws IOException on errors reading from the file * @throws URISyntaxException on errors during URI conversion */ public static MapMultiset<String, String> parseMapMultiset(final URL url, final int key) throws IOException, URISyntaxException { return parseMapMultiset(url, key, Charsets.UTF_8); } }