Java tutorial
/** * Copyright (c) 2000-2012 Liferay, Inc. All rights reserved. * * This library is free software; you can redistribute it and/or modify it under * the terms of the GNU Lesser General Public License as published by the Free * Software Foundation; either version 2.1 of the License, or (at your option) * any later version. * * This library is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more * details. */ package com.liferay.portlet.amazonrankings.util; import com.liferay.portal.kernel.log.Log; import com.liferay.portal.kernel.log.LogFactoryUtil; import com.liferay.portal.kernel.util.DateFormatFactoryUtil; import com.liferay.portal.kernel.util.GetterUtil; import com.liferay.portal.kernel.util.HttpUtil; import com.liferay.portal.kernel.util.StringPool; import com.liferay.portal.kernel.util.Time; import com.liferay.portal.kernel.util.Validator; import com.liferay.portal.kernel.webcache.WebCacheItem; import com.liferay.portal.kernel.xml.Document; import com.liferay.portal.kernel.xml.Element; import com.liferay.portal.kernel.xml.SAXReaderUtil; import com.liferay.portlet.amazonrankings.model.AmazonRankings; import java.text.DateFormat; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.List; import java.util.Locale; import java.util.Map; /** * @author Brian Wing Shun Chan * @author Samuel Kong * @author Barrie Selack */ public class AmazonRankingsWebCacheItem implements WebCacheItem { public AmazonRankingsWebCacheItem(String isbn) { _isbn = isbn; } public Object convert(String key) { AmazonRankings amazonRankings = null; try { amazonRankings = doConvert(key); } catch (Exception e) { _log.error(e, e); } return amazonRankings; } public long getRefreshTime() { return _REFRESH_TIME; } protected AmazonRankings doConvert(String key) throws Exception { Map<String, String> parameters = new HashMap<String, String>(); parameters.put("AWSAccessKeyId", AmazonRankingsUtil.getAmazonAccessKeyId()); parameters.put("IdType", "ASIN"); parameters.put("ItemId", _isbn); parameters.put("Operation", "ItemLookup"); parameters.put("ResponseGroup", "Images,ItemAttributes,Offers,SalesRank"); parameters.put("Service", "AWSECommerceService"); parameters.put("Timestamp", AmazonRankingsUtil.getTimestamp()); String urlWithSignature = AmazonSignedRequestsUtil.generateUrlWithSignature(parameters); String xml = HttpUtil.URLtoString(urlWithSignature); Document document = SAXReaderUtil.read(xml); Element rootElement = document.getRootElement(); if (rootElement == null) { return null; } if (hasErrorMessage(rootElement)) { return null; } Element itemsElement = rootElement.element("Items"); if (itemsElement == null) { return null; } Element requestElement = itemsElement.element("Request"); if (requestElement != null) { Element errorsElement = requestElement.element("Errors"); if (hasErrorMessage(errorsElement)) { return null; } } Element itemElement = itemsElement.element("Item"); if (itemElement == null) { return null; } Element itemAttributesElement = itemElement.element("ItemAttributes"); if (itemAttributesElement == null) { return null; } String productName = itemAttributesElement.elementText("Title"); String catalog = StringPool.BLANK; String[] authors = getAuthors(itemAttributesElement); String releaseDateAsString = itemAttributesElement.elementText("PublicationDate"); Date releaseDate = getReleaseDate(releaseDateAsString); String manufacturer = itemAttributesElement.elementText("Manufacturer"); String smallImageURL = getImageURL(itemElement, "SmallImage"); String mediumImageURL = getImageURL(itemElement, "MediumImage"); String largeImageURL = getImageURL(itemElement, "LargeImage"); double listPrice = getPrice(itemAttributesElement.element("ListPrice")); double ourPrice = 0; Element offerListingElement = getOfferListing(itemElement); if (offerListingElement != null) { ourPrice = getPrice(offerListingElement.element("Price")); } double usedPrice = 0; double collectiblePrice = 0; double thirdPartyNewPrice = 0; Element offerSummaryElement = itemElement.element("OfferSummary"); if (offerSummaryElement != null) { usedPrice = getPrice(offerSummaryElement.element("LowestUsedPrice")); collectiblePrice = getPrice(offerSummaryElement.element("LowestCollectiblePrice")); thirdPartyNewPrice = getPrice(offerSummaryElement.element("LowestNewPrice")); } int salesRank = GetterUtil.getInteger(itemElement.elementText("SalesRank")); String media = StringPool.BLANK; String availability = getAvailability(offerListingElement); return new AmazonRankings(_isbn, productName, catalog, authors, releaseDate, releaseDateAsString, manufacturer, smallImageURL, mediumImageURL, largeImageURL, listPrice, ourPrice, usedPrice, collectiblePrice, thirdPartyNewPrice, salesRank, media, availability); } protected String[] getAuthors(Element itemAttributesElement) { List<String> authors = new ArrayList<String>(); for (Element authorElement : itemAttributesElement.elements("Author")) { authors.add(authorElement.getText()); } return authors.toArray(new String[authors.size()]); } protected String getAvailability(Element offerListingElement) { if (offerListingElement == null) { return null; } Element availabilityElement = offerListingElement.element("Availability"); return availabilityElement.elementText("Availability"); } protected String getImageURL(Element itemElement, String name) { String imageURL = null; Element imageElement = itemElement.element(name); if (imageElement != null) { imageURL = imageElement.elementText("URL"); } return imageURL; } protected Element getOfferListing(Element itemElement) { Element offersElement = itemElement.element("Offers"); if (offersElement == null) { return null; } Element offerElement = offersElement.element("Offer"); if (offerElement == null) { return null; } return offerElement.element("OfferListing"); } protected double getPrice(Element priceElement) { if (priceElement == null) { return 0; } return GetterUtil.getInteger(priceElement.elementText("Amount")) * 0.01; } protected Date getReleaseDate(String releaseDateAsString) { if (Validator.isNull(releaseDateAsString)) { return null; } DateFormat dateFormat = null; if (releaseDateAsString.length() > 7) { dateFormat = DateFormatFactoryUtil.getSimpleDateFormat("yyyy-MM-dd", Locale.US); } else { dateFormat = DateFormatFactoryUtil.getSimpleDateFormat("yyyy-MM", Locale.US); } return GetterUtil.getDate(releaseDateAsString, dateFormat); } protected boolean hasErrorMessage(Element element) { if (element == null) { return false; } Element errorElement = element.element("Error"); if (errorElement == null) { return false; } Element messageElement = errorElement.element("Message"); if (messageElement == null) { return false; } _log.error(messageElement.getText()); return true; } private static final long _REFRESH_TIME = Time.MINUTE * 20; private static Log _log = LogFactoryUtil.getLog(AmazonRankingsWebCacheItem.class); private String _isbn; }