Java tutorial
/* * Aipo is a groupware program developed by Aimluck,Inc. * Copyright (C) 2004-2015 Aimluck,Inc. * http://www.aipo.com * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as * published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * This program 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package com.aipo.container.gadgets.parse; import java.io.IOException; import java.io.StringReader; import java.util.Map; import java.util.Stack; import org.apache.commons.lang.StringUtils; import org.apache.shindig.common.xml.DomUtil; import org.apache.shindig.gadgets.GadgetException; import org.apache.shindig.gadgets.parse.GadgetHtmlParser; import org.apache.shindig.gadgets.parse.SocialDataTags; import org.apache.xerces.xni.Augmentations; import org.apache.xerces.xni.NamespaceContext; import org.apache.xerces.xni.QName; import org.apache.xerces.xni.XMLAttributes; import org.apache.xerces.xni.XMLDocumentHandler; import org.apache.xerces.xni.XMLLocator; import org.apache.xerces.xni.XMLResourceIdentifier; import org.apache.xerces.xni.XMLString; import org.apache.xerces.xni.XNIException; import org.apache.xerces.xni.parser.XMLDocumentSource; import org.apache.xerces.xni.parser.XMLInputSource; import org.cyberneko.html.HTMLConfiguration; import org.cyberneko.html.HTMLElements; import org.cyberneko.html.HTMLEntities; import org.cyberneko.html.HTMLScanner; import org.cyberneko.html.HTMLTagBalancer; import org.cyberneko.html.filters.NamespaceBinder; import org.w3c.dom.DOMException; import org.w3c.dom.DOMImplementation; import org.w3c.dom.Document; import org.w3c.dom.DocumentFragment; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import com.google.common.collect.ImmutableMap; import com.google.inject.Inject; import com.google.inject.Singleton; /** * Supports parsing of social markup blocks inside gadget content. * <script> elements with types of either "text/os-template" or * "text/os-data" are parsed inline into contained DOM hierarchies for * subsequent processing by the pipeline and template rewriters. */ @Singleton public class AipoNekoSimplifiedHtmlParser extends GadgetHtmlParser { private static final HTMLElements.Element OSML_TEMPLATE_ELEMENT; private static final HTMLElements.Element OSML_DATA_ELEMENT; static { HTMLElements.Element unknown = HTMLElements.getElement(HTMLElements.UNKNOWN); OSML_TEMPLATE_ELEMENT = new HTMLElements.Element(unknown.code, SocialDataTags.OSML_TEMPLATE_TAG, unknown.flags, HTMLElements.BODY, unknown.closes); // Passing parent in constructor is ignored. // Only allow template tags in BODY OSML_TEMPLATE_ELEMENT.parent = new HTMLElements.Element[] { HTMLElements.getElement(HTMLElements.BODY) }; // data tags are allowed in BODY only, since Neko disallows HEAD elements // from // having child elements of their own. OSML_DATA_ELEMENT = new HTMLElements.Element(unknown.code, SocialDataTags.OSML_TEMPLATE_TAG, unknown.flags, HTMLElements.BODY, unknown.closes); OSML_DATA_ELEMENT.parent = new HTMLElements.Element[] { HTMLElements.getElement(HTMLElements.BODY) }; } private static final Map<String, HTMLElements.Element> OSML_ELEMENTS = ImmutableMap.of( SocialDataTags.OSML_TEMPLATE_TAG, OSML_TEMPLATE_ELEMENT, SocialDataTags.OSML_DATA_TAG, OSML_DATA_ELEMENT); @Inject public AipoNekoSimplifiedHtmlParser(DOMImplementation documentFactory) { super(documentFactory); } @Override protected Document parseDomImpl(String source) throws GadgetException { DocumentHandler handler; HTMLConfiguration config = newConfiguration(); try { handler = parseHtmlImpl(source, config, new NormalizingTagBalancer()); } catch (IOException ioe) { return null; } Document document = handler.getDocument(); document.appendChild(DomUtil.getFirstNamedChildNode(handler.getFragment(), "html")); fixNekoWeirdness(document); return document; } @Override protected DocumentFragment parseFragmentImpl(String source) throws GadgetException { DocumentHandler handler; HTMLConfiguration config = newConfiguration(); // http://cyberneko.org/html/features/balance-tags/document-fragment // deprecated http://cyberneko.org/html/features/document-fragment config.setFeature("http://cyberneko.org/html/features/balance-tags/document-fragment", true); config.setProperty("http://cyberneko.org/html/properties/balance-tags/fragment-context-stack", new QName[] { new QName(null, "HTML", "HTML", null), new QName(null, "BODY", "BODY", null) }); try { handler = parseHtmlImpl(source, config, new NekoPatchTagBalancer()); } catch (IOException ioe) { return null; } return handler.getFragment(); } /** * Parse HTML source. * * @return a document handler containing the parsed source */ private DocumentHandler parseHtmlImpl(String source, HTMLConfiguration config, NormalizingTagBalancer tagBalancer) throws IOException { HTMLScanner htmlScanner = new HTMLScanner(); tagBalancer.setScanner(htmlScanner); DocumentHandler handler = newDocumentHandler(source); NamespaceBinder namespaceBinder = new NamespaceBinder(); namespaceBinder.setDocumentHandler(handler); namespaceBinder.setDocumentSource(tagBalancer); namespaceBinder.reset(config); tagBalancer.setDocumentHandler(namespaceBinder); // Order of filter is Scanner -> OSMLFilter -> Tag Balancer tagBalancer.setDocumentSource(htmlScanner); htmlScanner.setDocumentHandler(tagBalancer); tagBalancer.reset(config); htmlScanner.reset(config); XMLInputSource inputSource = new XMLInputSource(null, null, null); inputSource.setEncoding("UTF-8"); inputSource.setCharacterStream(new StringReader(source)); htmlScanner.setInputSource(inputSource); htmlScanner.scanDocument(true); return handler; } private void fixNekoWeirdness(Document document) { // Neko as of versions > 1.9.13 stuffs all leading <script> nodes into // <head>. // This breaks all sorts of assumptions in gadgets, notably the existence of // document.body. // We can't tell Neko to avoid putting <script> into <head> however, since // gadgets // like <Content><script>...</script><style>...</style> will break due to // both // <script> and <style> ending up in <body> -- at which point Neko // unceremoniously // drops the <style> (and <link>) elements. // Therefore we just search for <script> elements in <head> and stuff them // all into // the top of <body>. // This method assumes a normalized document as input. Node html = DomUtil.getFirstNamedChildNode(document, "html"); if (html.getNextSibling() != null && html.getNextSibling().getNodeName().equalsIgnoreCase("html")) { // if a doctype is specified, then the desired root <html> node is wrapped // by an <HTML> node // Pull out the <html> root. html = html.getNextSibling(); } Node head = DomUtil.getFirstNamedChildNode(html, "head"); if (head == null) { head = document.createElement("head"); html.insertBefore(head, html.getFirstChild()); } NodeList headNodes = head.getChildNodes(); Stack<Node> headScripts = new Stack<Node>(); for (int i = 0; i < headNodes.getLength(); ++i) { Node headChild = headNodes.item(i); if (headChild.getNodeName().equalsIgnoreCase("script")) { headScripts.add(headChild); } } // Remove from head, add to top of <body> in <head> order. Node body = DomUtil.getFirstNamedChildNode(html, "body"); if (body == null) { body = document.createElement("body"); html.insertBefore(body, head.getNextSibling()); } Node bodyFirst = body.getFirstChild(); while (!headScripts.isEmpty()) { Node headScript = headScripts.pop(); head.removeChild(headScript); body.insertBefore(headScript, bodyFirst); bodyFirst = headScript; } } protected HTMLConfiguration newConfiguration() { HTMLConfiguration config = new HTMLConfiguration(); // Maintain original case for elements and attributes config.setProperty("http://cyberneko.org/html/properties/names/elems", "match"); config.setProperty("http://cyberneko.org/html/properties/names/attrs", "no-change"); // Get notified of entity and character references config.setFeature("http://apache.org/xml/features/scanner/notify-char-refs", true); config.setFeature("http://cyberneko.org/html/features/scanner/notify-builtin-refs", true); config.setFeature("http://xml.org/sax/features/namespaces", true); return config; } protected DocumentHandler newDocumentHandler(String source) { return new DocumentHandler(source); } /** Handler for XNI events from Neko */ protected class DocumentHandler implements XMLDocumentHandler { private final Stack<Node> elementStack = new Stack<Node>(); private final StringBuilder builder; private boolean inEntity = false; private DocumentFragment documentFragment; private Document document; public DocumentHandler(String content) { builder = new StringBuilder(content.length() / 10); } public DocumentFragment getFragment() { return documentFragment; } public Document getDocument() { return document; } public void startDocument(XMLLocator xmlLocator, String encoding, NamespaceContext namespaceContext, Augmentations augs) throws XNIException { document = documentFactory.createDocument(null, null, documentFactory.createDocumentType("html", "-//W3C//DTD XHTML 1.0 Transitional//EN", "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd")); elementStack.clear(); documentFragment = document.createDocumentFragment(); elementStack.push(documentFragment); } public void xmlDecl(String version, String encoding, String standalone, Augmentations augs) throws XNIException { // Dont really do anything with this builder.append("<?xml"); if (version != null) { builder.append(" version=\"").append(version).append('\"'); } if (encoding != null) { builder.append(" encoding=\"").append(encoding).append('\"'); } if (standalone != null) { builder.append(" standalone=\"").append(standalone).append('\"'); } builder.append('>'); } public void doctypeDecl(String rootElement, String publicId, String systemId, Augmentations augs) throws XNIException { document = documentFactory.createDocument(null, null, documentFactory.createDocumentType(rootElement, publicId, systemId)); elementStack.clear(); documentFragment = document.createDocumentFragment(); elementStack.push(documentFragment); } public void comment(XMLString text, Augmentations augs) throws XNIException { flushTextBuffer(); // Add comments as comment nodes - needed to support sanitization // of SocialMarkup-parsed content Node comment = getDocument().createComment(new String(text.ch, text.offset, text.length)); appendChild(comment); } public void processingInstruction(String s, XMLString xmlString, Augmentations augs) throws XNIException { // No-op } public void startElement(QName qName, XMLAttributes xmlAttributes, Augmentations augs) throws XNIException { Element element = startElementImpl(qName, xmlAttributes); // Not an empty element, so push on the stack elementStack.push(element); } public void emptyElement(QName qName, XMLAttributes xmlAttributes, Augmentations augs) throws XNIException { startElementImpl(qName, xmlAttributes); } /** * Flush any existing text content to the document. Call this before * appending any nodes. */ protected void flushTextBuffer() { if (builder.length() > 0) { appendChild(document.createTextNode(builder.toString())); builder.setLength(0); } } /** Create an Element in the DOM */ private Element startElementImpl(QName qName, XMLAttributes xmlAttributes) { flushTextBuffer(); Element element; // Preserve XML namespace if present if (qName.uri != null) { element = document.createElementNS(qName.uri, qName.rawname); } else { element = document.createElement(qName.rawname); } for (int i = 0; i < xmlAttributes.getLength(); i++) { if (xmlAttributes.getURI(i) != null) { element.setAttributeNS(xmlAttributes.getURI(i), xmlAttributes.getQName(i), xmlAttributes.getValue(i)); } else { try { element.setAttribute(xmlAttributes.getLocalName(i), xmlAttributes.getValue(i)); } catch (DOMException e) { switch (e.code) { case DOMException.INVALID_CHARACTER_ERR: StringBuilder sb = new StringBuilder(e.getMessage()); sb.append("Around ...<"); if (qName.prefix != null) { sb.append(qName.prefix); sb.append(':'); } sb.append(qName.localpart); for (int j = 0; j < xmlAttributes.getLength(); j++) { if (StringUtils.isNotBlank(xmlAttributes.getLocalName(j)) && StringUtils.isNotBlank(xmlAttributes.getValue(j))) { sb.append(' '); sb.append(xmlAttributes.getLocalName(j)); sb.append("=\""); sb.append(xmlAttributes.getValue(j)).append('\"'); } } sb.append("..."); throw new DOMException(DOMException.INVALID_CHARACTER_ERR, sb.toString()); default: throw e; } } } } appendChild(element); return element; } public void startGeneralEntity(String name, XMLResourceIdentifier id, String encoding, Augmentations augs) throws XNIException { if (name.startsWith("#")) { try { boolean hex = name.startsWith("#x"); int offset = hex ? 2 : 1; int base = hex ? 16 : 10; int value = Integer.parseInt(name.substring(offset), base); String entity = HTMLEntities.get(value); if (entity != null) { name = entity; } } catch (NumberFormatException e) { // ignore } } printEntity(name); inEntity = true; } private void printEntity(String name) { builder.append('&'); builder.append(name); builder.append(';'); } public void textDecl(String s, String s1, Augmentations augs) throws XNIException { builder.append(s); } public void endGeneralEntity(String s, Augmentations augs) throws XNIException { inEntity = false; } public void characters(XMLString text, Augmentations augs) throws XNIException { if (inEntity) { return; } builder.append(text.ch, text.offset, text.length); } public void ignorableWhitespace(XMLString text, Augmentations augs) throws XNIException { builder.append(text.ch, text.offset, text.length); } public void endElement(QName qName, Augmentations augs) throws XNIException { flushTextBuffer(); elementStack.pop(); } public void startCDATA(Augmentations augs) throws XNIException { // No-op } public void endCDATA(Augmentations augs) throws XNIException { // No-op } public void endDocument(Augmentations augs) throws XNIException { flushTextBuffer(); elementStack.pop(); } public void setDocumentSource(XMLDocumentSource xmlDocumentSource) { } public XMLDocumentSource getDocumentSource() { return null; } private void appendChild(Node node) { elementStack.peek().appendChild(node); } } /** * Used when parsing document fragments to correct a bug in Neko 1.9.13. We * use the * http://cyberneko.org/html/properties/balance-tags/fragment-context-stack * property of Neko to force the fragment to be parsed as if it were already * container in a body tag. This doesnt quite work together as without this * fix it will still introduce head tags if the first parsed tags are allowed * in a head tag. See * https://sourceforge.net/tracker/?func=detail&atid=952178& * aid=2870180&group_id=195122 */ private static class NekoPatchTagBalancer extends NormalizingTagBalancer { /** * Override the document start to record whether HTML, HEAD or BODY have * been seen */ @Override public void startDocument(XMLLocator locator, String encoding, NamespaceContext nscontext, Augmentations augs) throws XNIException { super.startDocument(locator, encoding, nscontext, augs); for (int i = fElementStack.top - 1; i >= 0; i--) { fSeenAnything = true; if (fElementStack.data[i].element.code == HTMLElements.HTML) { fSeenRootElement = true; } if (fElementStack.data[i].element.code == HTMLElements.HEAD) { fSeenHeadElement = true; } if (fElementStack.data[i].element.code == HTMLElements.BODY) { fSeenBodyElement = true; } } } } /** * Subclass of Neko's tag balancer that - Normalizes the case of forced html, * head and body tags when they don't exist in the original content. - Convert * script tags with type=os/* to OSData and OSTemplate. Record their text * content and force it to be reparsed. - */ private static class NormalizingTagBalancer extends HTMLTagBalancer { private StringBuilder scriptContent; private HTMLScanner scanner; private QName currentOsmlTag; public NormalizingTagBalancer() { } public void setScanner(HTMLScanner scanner) { this.scanner = scanner; } @Override public void characters(XMLString text, Augmentations augs) throws XNIException { if (currentOsmlTag != null) { scriptContent.append(text.ch, text.offset, text.length); } else { super.characters(text, augs); } } @Override public void startElement(QName elem, XMLAttributes attrs, Augmentations augs) throws XNIException { // Normalize the case of forced-elements to lowercase for backward // compatability if (!fSeenRootElement && elem.rawname.equalsIgnoreCase("html")) { elem.localpart = "html"; elem.rawname = "html"; } else if (!fSeenHeadElement && elem.rawname.equalsIgnoreCase("head")) { elem.localpart = "head"; elem.rawname = "head"; } else if (!fSeenBodyElement && elem.rawname.equalsIgnoreCase("body")) { elem.localpart = "body"; elem.rawname = "body"; } // Convert script tags of an OSML type to OSTemplate/OSData tags if ("script".equalsIgnoreCase(elem.rawname)) { String value = attrs.getValue("type"); String osmlTagName = SocialDataTags.SCRIPT_TYPE_TO_OSML_TAG.get(value); if (osmlTagName != null) { if (currentOsmlTag != null) { throw new XNIException("Nested OpenSocial script elements"); } currentOsmlTag = new QName(null, osmlTagName, osmlTagName, null); if (scriptContent == null) { scriptContent = new StringBuilder(); } // Remove the type attribute attrs.removeAttributeAt(attrs.getIndex("type")); super.startElement(currentOsmlTag, attrs, augs); return; } } super.startElement(elem, attrs, augs); } @Override public void endElement(QName element, Augmentations augs) throws XNIException { if (currentOsmlTag != null && "script".equalsIgnoreCase(element.rawname)) { QName endingTag = currentOsmlTag; currentOsmlTag = null; XMLInputSource scriptSource = new XMLInputSource(null, null, null); scriptSource.setCharacterStream(new StringReader(scriptContent.toString())); scriptContent.setLength(0); // Evaluate the content of the script block immediately scanner.evaluateInputSource(scriptSource); super.endElement(endingTag, augs); } else { super.endElement(element, augs); } } @Override protected HTMLElements.Element getElement(QName elementName) { HTMLElements.Element osmlElement = OSML_ELEMENTS.get(elementName.localpart); if (osmlElement != null) { return osmlElement; } return super.getElement(elementName); } } }