Java tutorial
/* * Copyright 2008-2015 Jose Luis Martin. * * 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 org.jdal.xml; import java.io.ByteArrayInputStream; import java.io.File; import java.io.IOException; import java.io.StringWriter; import java.net.URL; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; import javax.xml.transform.Source; import javax.xml.transform.dom.DOMSource; import javax.xml.transform.stream.StreamSource; import javax.xml.validation.Schema; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.xml.serialize.OutputFormat; import org.apache.xml.serialize.XMLSerializer; import org.w3c.dom.CDATASection; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.NamedNodeMap; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.w3c.dom.Text; import org.xml.sax.SAXException; /** * XML DOM Utility static lib for XML (Thread safe) * Cache the DOM DocumentBuilder in thread local variable. * * @author Jose Luis Martin - (jlm@joseluismartin.info) */ public abstract class XMLUtils { /** commons log */ private static Log log = LogFactory.getLog(XMLUtils.class); /** Cache a DocumentBuilder */ private static ThreadLocal<DocumentBuilder> dbLocal = new ThreadLocal<DocumentBuilder>(); /** * Get a org.w3c.Document from resource String * @param res ResourceString * @return a new org.w3c.Document */ public static Document newDocumentFromResource(String res) { URL url = XMLUtils.class.getResource(res); return url != null ? newDocumentFromFile(url.getFile()) : null; } /** * Get a new org.w3c.Document from files String * @param path ResourceString * @return a new org.w3c.Document */ public static Document newDocumentFromFile(String path) { Document doc = null; try { doc = getDocumentBuilder().parse(new File(path)); } catch (SAXException e) { log.error(e); } catch (IOException e) { log.error(e); } return doc; } /** * Get a new org.w3c.Document from xml string (UTF8) * @param xml string with xml * @return a new org.w3c.Document */ public static Document newDocument(String xml) { Document doc = null; DocumentBuilder db = getDocumentBuilder(); try { doc = db.parse(new ByteArrayInputStream(xml.getBytes("UTF8"))); } catch (Exception e) { log.error(e); } return doc; } /** * Get new instance of DOM Document * @return a new instance of DOM Document */ public static Document newDocument() { return getDocumentBuilder().newDocument(); } /** * Get a DocumentBuilder from a ThreadLocal variable, * Create if null * * @return DocumentBuilder */ public static DocumentBuilder getDocumentBuilder() { DocumentBuilder db = (DocumentBuilder) dbLocal.get(); if (db == null) { DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); dbf.setNamespaceAware(true); // dbf.setValidating(true); try { db = dbf.newDocumentBuilder(); dbLocal.set(db); } catch (ParserConfigurationException e) { log.error(e); } } return db; } /** * Serialize a Document to a String using JAXP with identation (4 spaces) * @param doc to serialize * @return xml string */ public static String prettyDocumentToString(Document doc) { StringWriter writer = new StringWriter(); OutputFormat out = new OutputFormat(); out.setOmitXMLDeclaration(true); out.setIndenting(true); out.setIndent(4); out.setLineSeparator(System.getProperty("line.separator")); out.setLineWidth(Integer.MAX_VALUE); XMLSerializer serializer = new XMLSerializer(writer, out); try { Element rootElement = doc.getDocumentElement(); serializer.serialize(rootElement); } catch (IOException e) { log.error(e); } return writer.toString(); } /** * Serialize a Document to a Sring using JAXP without formating * * @param doc Document to serialize * @return Strin with serialized doc */ public static String documentToString(Document doc) { return elementToString(doc.getDocumentElement()); } /** * Element to String without format * * @param elto to serialize * @return serialized elto */ public static String elementToString(Element elto) { StringWriter writer = new StringWriter(); OutputFormat of = new OutputFormat(); of.setOmitXMLDeclaration(true); XMLSerializer serializer = new XMLSerializer(writer, of); serializer.setNamespaces(true); try { serializer.serialize(elto); } catch (IOException ioe) { log.error(ioe); } return writer.toString(); } /** * Get a DOM Element from xml string * @param xml the string to parse * @return a new DOM Element */ public static Element stringToElement(String xml) { Document doc = newDocument(xml); Element elto = doc.getDocumentElement(); return (Element) elto.cloneNode(true); } /** * Copy one node to another node. * @param source source Node * @param dest destination Node * @return destination Node */ public static synchronized Node copyNode(Node source, Node dest) { if (source.getNodeType() == Node.TEXT_NODE) { Text tn = dest.getOwnerDocument().createTextNode(source.getNodeValue()); return tn; } Node attr = null; NamedNodeMap attrs = source.getAttributes(); if (attrs != null) { for (int i = 0; i < attrs.getLength(); i++) { attr = attrs.item(i); ((Element) dest).setAttribute(attr.getNodeName(), attr.getNodeValue()); } } Node child = null; NodeList list = source.getChildNodes(); for (int i = 0; i < list.getLength(); i++) { child = list.item(i); if (!(child instanceof Text)) { Element en = dest.getOwnerDocument().createElementNS(child.getNamespaceURI(), child.getNodeName()); if (child.getNodeValue() != null) { en.setNodeValue(child.getNodeValue()); } Node n = copyNode(child, en); dest.appendChild(n); } else if (child instanceof CDATASection) { CDATASection cd = dest.getOwnerDocument().createCDATASection(child.getNodeValue()); dest.appendChild(cd); } else { Text tn = dest.getOwnerDocument().createTextNode(child.getNodeValue()); dest.appendChild(tn); } } return dest; } /** * Creates a new Document with name and namespace * @param ns namespace * @param name name * @return new Document */ public static Document newDocument(String ns, String name) { return getDocumentBuilder().getDOMImplementation().createDocument(ns, name, null); } /** * Validate a Document with schema * @param xml to validate * @param schema to falidate from * @return a ValidationResult with validation result */ public static ValidationResult validateSchema(String xml, Schema schema) { try { ByteArrayInputStream bais = new ByteArrayInputStream(xml.getBytes("UTF-8")); Source xmlSource = new StreamSource(bais); schema.newValidator().validate(xmlSource); } catch (Exception e) { log.warn(e); return new ValidationResult(false, e.getMessage()); } return new ValidationResult(true); } /** * Validate Document on schema * @param doc to validate * @param schema for validation * @return a ValidationResult with validatin result */ public static ValidationResult validateSchema(Document doc, Schema schema) { try { Source xmlSource = new DOMSource(doc); schema.newValidator().validate(xmlSource); } catch (Exception e) { log.warn(e); return new ValidationResult(false, e.getMessage()); } return new ValidationResult(true); } }