Java tutorial
/** * Copyright 2014 Dennis Rippinger * Licensed 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 info.interactivesystems.spade.similarity; import info.interactivesystems.spade.dao.NilsimsaSimilarityDao; import info.interactivesystems.spade.dao.service.ReviewContentService; import info.interactivesystems.spade.entities.NilsimsaSimilarity; import info.interactivesystems.spade.entities.Review; import lombok.extern.slf4j.Slf4j; import org.joda.time.DateTime; import org.joda.time.Days; import org.springframework.stereotype.Component; import javax.annotation.Resource; import java.util.Date; import java.util.List; /** * The Class MissingCategoriesResolver. * * @author Dennis Rippinger */ @Slf4j @Component public class MissingCategoriesResolver { @Resource private ReviewContentService service; @Resource private NilsimsaSimilarityDao similartyDao; @Resource private NilsimsaSimilarityDao nisimsaDao; @Resource private NilsimsaHash hash; public void resolveMissingCategory(String category, List<String> suspiciousUsers, boolean partitialyScanned) { List<Review> categorryReviews = service.findReviewsByCategory(category); for (Integer counter = 0; counter < suspiciousUsers.size(); counter++) { log.info("Category: '{}'. User '{}': {} / {}", category, suspiciousUsers.get(counter), counter, suspiciousUsers.size()); List<Review> userReviewsInCategory = service.findReviewFromUserInCategory(suspiciousUsers.get(counter), category); if (!userReviewsInCategory.isEmpty()) { calculateSimilarities(categorryReviews, userReviewsInCategory, category, partitialyScanned); } } categorryReviews = null; System.gc(); } private void calculateSimilarities(List<Review> allCategoryReviews, List<Review> userReviewsInCategory, String category, boolean partitialyScanned) { for (Review userReview : userReviewsInCategory) { for (Review categoryReview : allCategoryReviews) { if (userReview.getId().equals(categoryReview.getId())) { continue; } Integer sameBits = hash.compare(userReview.getNilsimsa(), categoryReview.getNilsimsa()); Double percentage = sameBits / 128.0; if (percentage >= 0.85) { /* * Check if pair already exists */ if (partitialyScanned) { NilsimsaSimilarity existingPair = nisimsaDao.findSimilarityByReviewId(userReview.getId(), categoryReview.getId()); if (existingPair != null) { continue; } } /* * DAO for this resolver only returns a minimal projection of a review. Therefore more is loaded on success. */ Review realUserReview = service.findReview(userReview.getId()); Review realCategoryReview = service.findReview(categoryReview.getId()); NilsimsaSimilarity similarity = new NilsimsaSimilarity(); similarity.setReviewA(realUserReview); similarity.setReviewB(realCategoryReview); similarity.setSimilarity(percentage); similarity.setCategory(category); Integer daysBetween = calculateDifference(realUserReview.getReviewDate(), realCategoryReview.getReviewDate()); Boolean sameAuthor = calculateSameAuthorship(realUserReview, realCategoryReview); Integer wordDistance = calculateWordDistance(realUserReview, realCategoryReview); similarity.setDayDistance(daysBetween); similarity.setSameAuthor(sameAuthor); similarity.setWordDistance(wordDistance); similarity.setUserA(realUserReview.getUser()); similarity.setUserB(realCategoryReview.getUser()); nisimsaDao.save(similarity); } } } } private Integer calculateWordDistance(Review reviewA, Review reviewB) { Integer difference = reviewA.getWordCount() - reviewB.getWordCount(); if (difference < 0) { difference = difference * -1; } return difference; } private Boolean calculateSameAuthorship(Review reviewA, Review reviewB) { return reviewA.getUser().getId().equals(reviewB.getUser().getId()); } private Integer calculateDifference(Date reviewDate, Date reviewDate2) { Integer days = Days.daysBetween(new DateTime(reviewDate), new DateTime(reviewDate2)).getDays(); if (days < 0) { days = days * -1; } return days; } }