Java tutorial
/* * Copyright 2004 Sun Microsystems, Inc. * * 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 com.sun.syndication.io.impl; import com.sun.syndication.feed.WireFeed; import com.sun.syndication.feed.atom.*; import com.sun.syndication.io.FeedException; import org.jdom2.Attribute; import org.jdom2.Document; import org.jdom2.Element; import org.jdom2.Namespace; import org.jdom2.input.SAXBuilder; import java.io.StringReader; import java.util.List; /** * Feed Generator for Atom * <p/> * * @author Elaine Chien * */ public class Atom03Generator extends BaseWireFeedGenerator { private static final String ATOM_03_URI = "http://purl.org/atom/ns#"; private static final Namespace ATOM_NS = Namespace.getNamespace(ATOM_03_URI); private String _version; public Atom03Generator() { this("atom_0.3", "0.3"); } protected Atom03Generator(String type, String version) { super(type); _version = version; } protected String getVersion() { return _version; } protected Namespace getFeedNamespace() { return ATOM_NS; } public Document generate(WireFeed wFeed) throws FeedException { Feed feed = (Feed) wFeed; Element root = createRootElement(feed); populateFeed(feed, root); purgeUnusedNamespaceDeclarations(root); return createDocument(root); } protected Document createDocument(Element root) { return new Document(root); } protected Element createRootElement(Feed feed) { Element root = new Element("feed", getFeedNamespace()); root.addNamespaceDeclaration(getFeedNamespace()); Attribute version = new Attribute("version", getVersion()); root.setAttribute(version); generateModuleNamespaceDefs(root); return root; } protected void populateFeed(Feed feed, Element parent) throws FeedException { addFeed(feed, parent); addEntries(feed, parent); } protected void addFeed(Feed feed, Element parent) throws FeedException { Element eFeed = parent; populateFeedHeader(feed, eFeed); checkFeedHeaderConstraints(eFeed); generateFeedModules(feed.getModules(), eFeed); generateForeignMarkup(eFeed, (List) feed.getForeignMarkup()); } protected void addEntries(Feed feed, Element parent) throws FeedException { List items = feed.getEntries(); for (int i = 0; i < items.size(); i++) { addEntry((Entry) items.get(i), parent); } checkEntriesConstraints(parent); } protected void addEntry(Entry entry, Element parent) throws FeedException { Element eEntry = new Element("entry", getFeedNamespace()); populateEntry(entry, eEntry); checkEntryConstraints(eEntry); generateItemModules(entry.getModules(), eEntry); parent.addContent(eEntry); } protected void populateFeedHeader(Feed feed, Element eFeed) throws FeedException { if (feed.getTitleEx() != null) { Element titleElement = new Element("title", getFeedNamespace()); fillContentElement(titleElement, feed.getTitleEx()); eFeed.addContent(titleElement); } List links = feed.getAlternateLinks(); for (int i = 0; i < links.size(); i++) { eFeed.addContent(generateLinkElement((Link) links.get(i))); } links = feed.getOtherLinks(); for (int i = 0; i < links.size(); i++) { eFeed.addContent(generateLinkElement((Link) links.get(i))); } if (feed.getAuthors() != null && feed.getAuthors().size() > 0) { Element authorElement = new Element("author", getFeedNamespace()); fillPersonElement(authorElement, (Person) feed.getAuthors().get(0)); eFeed.addContent(authorElement); } List contributors = feed.getContributors(); for (int i = 0; i < contributors.size(); i++) { Element contributorElement = new Element("contributor", getFeedNamespace()); fillPersonElement(contributorElement, (Person) contributors.get(i)); eFeed.addContent(contributorElement); } if (feed.getTagline() != null) { Element taglineElement = new Element("tagline", getFeedNamespace()); fillContentElement(taglineElement, feed.getTagline()); eFeed.addContent(taglineElement); } if (feed.getId() != null) { eFeed.addContent(generateSimpleElement("id", feed.getId())); } if (feed.getGenerator() != null) { eFeed.addContent(generateGeneratorElement(feed.getGenerator())); } if (feed.getCopyright() != null) { eFeed.addContent(generateSimpleElement("copyright", feed.getCopyright())); } if (feed.getInfo() != null) { Element infoElement = new Element("info", getFeedNamespace()); fillContentElement(infoElement, feed.getInfo()); eFeed.addContent(infoElement); } if (feed.getModified() != null) { Element modifiedElement = new Element("modified", getFeedNamespace()); modifiedElement.addContent(DateParser.formatW3CDateTime(feed.getModified())); eFeed.addContent(modifiedElement); } } protected void populateEntry(Entry entry, Element eEntry) throws FeedException { if (entry.getTitleEx() != null) { Element titleElement = new Element("title", getFeedNamespace()); fillContentElement(titleElement, entry.getTitleEx()); eEntry.addContent(titleElement); } List links = entry.getAlternateLinks(); for (int i = 0; i < links.size(); i++) { eEntry.addContent(generateLinkElement((Link) links.get(i))); } links = entry.getOtherLinks(); for (int i = 0; i < links.size(); i++) { eEntry.addContent(generateLinkElement((Link) links.get(i))); } if (entry.getAuthors() != null && entry.getAuthors().size() > 0) { Element authorElement = new Element("author", getFeedNamespace()); fillPersonElement(authorElement, (Person) entry.getAuthors().get(0)); eEntry.addContent(authorElement); } List contributors = entry.getContributors(); for (int i = 0; i < contributors.size(); i++) { Element contributorElement = new Element("contributor", getFeedNamespace()); fillPersonElement(contributorElement, (Person) contributors.get(i)); eEntry.addContent(contributorElement); } if (entry.getId() != null) { eEntry.addContent(generateSimpleElement("id", entry.getId())); } if (entry.getModified() != null) { Element modifiedElement = new Element("modified", getFeedNamespace()); modifiedElement.addContent(DateParser.formatW3CDateTime(entry.getModified())); eEntry.addContent(modifiedElement); } if (entry.getIssued() != null) { Element issuedElement = new Element("issued", getFeedNamespace()); issuedElement.addContent(DateParser.formatW3CDateTime(entry.getIssued())); eEntry.addContent(issuedElement); } if (entry.getCreated() != null) { Element createdElement = new Element("created", getFeedNamespace()); createdElement.addContent(DateParser.formatW3CDateTime(entry.getCreated())); eEntry.addContent(createdElement); } if (entry.getSummary() != null) { Element summaryElement = new Element("summary", getFeedNamespace()); fillContentElement(summaryElement, entry.getSummary()); eEntry.addContent(summaryElement); } List contents = entry.getContents(); for (int i = 0; i < contents.size(); i++) { Element contentElement = new Element("content", getFeedNamespace()); fillContentElement(contentElement, (Content) contents.get(i)); eEntry.addContent(contentElement); } generateForeignMarkup(eEntry, (List) entry.getForeignMarkup()); } protected void checkFeedHeaderConstraints(Element eFeed) throws FeedException { } protected void checkEntriesConstraints(Element parent) throws FeedException { } protected void checkEntryConstraints(Element eEntry) throws FeedException { } protected Element generateLinkElement(Link link) { Element linkElement = new Element("link", getFeedNamespace()); if (link.getRel() != null) { Attribute relAttribute = new Attribute("rel", link.getRel().toString()); linkElement.setAttribute(relAttribute); } if (link.getType() != null) { Attribute typeAttribute = new Attribute("type", link.getType()); linkElement.setAttribute(typeAttribute); } if (link.getHref() != null) { Attribute hrefAttribute = new Attribute("href", link.getHref()); linkElement.setAttribute(hrefAttribute); } return linkElement; } protected void fillPersonElement(Element element, Person person) { if (person.getName() != null) { element.addContent(generateSimpleElement("name", person.getName())); } if (person.getUrl() != null) { element.addContent(generateSimpleElement("url", person.getUrl())); } if (person.getEmail() != null) { element.addContent(generateSimpleElement("email", person.getEmail())); } } protected Element generateTagLineElement(Content tagline) { Element taglineElement = new Element("tagline", getFeedNamespace()); if (tagline.getType() != null) { Attribute typeAttribute = new Attribute("type", tagline.getType()); taglineElement.setAttribute(typeAttribute); } if (tagline.getValue() != null) { taglineElement.addContent(tagline.getValue()); } return taglineElement; } protected void fillContentElement(Element contentElement, Content content) throws FeedException { if (content.getType() != null) { Attribute typeAttribute = new Attribute("type", content.getType()); contentElement.setAttribute(typeAttribute); } String mode = content.getMode(); if (mode != null) { Attribute modeAttribute = new Attribute("mode", content.getMode().toString()); contentElement.setAttribute(modeAttribute); } if (content.getValue() != null) { if (mode == null || mode.equals(Content.ESCAPED)) { contentElement.addContent(content.getValue()); } else if (mode.equals(Content.BASE64)) { contentElement.addContent(Base64.encode(content.getValue())); } else if (mode.equals(Content.XML)) { StringBuffer tmpDocString = new StringBuffer("<tmpdoc>"); tmpDocString.append(content.getValue()); tmpDocString.append("</tmpdoc>"); StringReader tmpDocReader = new StringReader(tmpDocString.toString()); Document tmpDoc; try { SAXBuilder saxBuilder = new SAXBuilder(); tmpDoc = saxBuilder.build(tmpDocReader); } catch (Exception ex) { throw new FeedException("Invalid XML", ex); } List children = tmpDoc.getRootElement().removeContent(); contentElement.addContent(children); } } } protected Element generateGeneratorElement(Generator generator) { Element generatorElement = new Element("generator", getFeedNamespace()); if (generator.getUrl() != null) { Attribute urlAttribute = new Attribute("url", generator.getUrl()); generatorElement.setAttribute(urlAttribute); } if (generator.getVersion() != null) { Attribute versionAttribute = new Attribute("version", generator.getVersion()); generatorElement.setAttribute(versionAttribute); } if (generator.getValue() != null) { generatorElement.addContent(generator.getValue()); } return generatorElement; } protected Element generateSimpleElement(String name, String value) { Element element = new Element(name, getFeedNamespace()); element.addContent(value); return element; } }