Java tutorial
/* * NorthRidge Software, LLC - Copyright (c) 2019. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package com.nridge.core.base.io.xml; import com.nridge.core.base.doc.Relationship; import com.nridge.core.base.field.data.DataBag; import com.nridge.core.base.io.IO; import com.nridge.core.base.std.StrUtl; import org.apache.commons.lang3.StringUtils; import org.w3c.dom.*; import org.xml.sax.InputSource; import org.xml.sax.SAXException; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; import javax.xml.transform.TransformerException; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.Map; /** * The RelationshipXML provides a collection of methods that can generate/load * an XML representation of a {@link Relationship} object. * * @author Al Cole * @since 1.0 */ public class RelationshipXML implements DOMInterface { private Relationship mRelationship; private boolean mSaveFieldsWithoutValues; /** * Default constructor. */ public RelationshipXML() { mRelationship = new Relationship(); } /** * Constructor that identifies a relationship prior to a save operation. * * @param aRelationship Relationship instance. */ public RelationshipXML(Relationship aRelationship) { mRelationship = aRelationship; } /** * Assigning this to <i>true</i> will ensure all fields are written * (regardless of them having values assigned). Use this method * to generate schema files. * * @param aFlag <i>true</i> or <i>false</i> */ public void setSaveFieldsWithoutValues(boolean aFlag) { mSaveFieldsWithoutValues = aFlag; } /** * Returns a reference to the {@link Relationship} being managed by * this class. * * @return Relationship instance. */ public Relationship getRelationship() { return mRelationship; } /** * Saves the previous assigned relationship (e.g. via constructor or set method) * to the print writer stream wrapped in a tag name specified in the parameter. * * @param aPW PrintWriter stream instance. * @param aTagName Tag name. * @param anIndentAmount Indentation count. * * @throws java.io.IOException I/O related exception. */ @Override public void save(PrintWriter aPW, String aTagName, int anIndentAmount) throws IOException { DocumentXML documentXML; IOXML.indentLine(aPW, anIndentAmount); String typeName = mRelationship.getType(); String tagName = StringUtils.remove(aTagName, StrUtl.CHAR_SPACE); aPW.printf("<%s", tagName); IOXML.writeAttrNameValue(aPW, "type", typeName); for (Map.Entry<String, String> featureEntry : mRelationship.getFeatures().entrySet()) IOXML.writeAttrNameValue(aPW, featureEntry.getKey(), featureEntry.getValue()); aPW.printf(">%n"); DataBag dataBag = mRelationship.getBag(); if (dataBag.assignedCount() > 0) { DataBagXML dataBagXML = new DataBagXML(dataBag); dataBagXML.setBag(dataBag); dataBagXML.save(aPW, IO.XML_PROPERTIES_NODE_NAME, anIndentAmount + 1); } for (com.nridge.core.base.doc.Document document : mRelationship.getDocuments()) { documentXML = new DocumentXML(document); documentXML.setSaveFieldsWithoutValues(mSaveFieldsWithoutValues); documentXML.save(aPW, IO.XML_DOCUMENT_NODE_NAME, document, anIndentAmount + 1); } IOXML.indentLine(aPW, anIndentAmount); aPW.printf("</%s>%n", tagName); } /** * Saves the previous assigned relationship (e.g. via constructor or set method) * to the print writer stream specified as a parameter. * * @param aPW PrintWriter stream instance. * * @throws java.io.IOException I/O related exception. */ @Override public void save(PrintWriter aPW) throws IOException { save(aPW, IO.XML_RELATIONSHIP_NODE_NAME, 0); } /** * Saves the previous assigned relationship (e.g. via constructor or set method) * to the path/file name specified as a parameter. * * @param aPathFileName Absolute file name. * * @throws java.io.IOException I/O related exception. */ @Override public void save(String aPathFileName) throws IOException { try (PrintWriter printWriter = new PrintWriter(aPathFileName, StrUtl.CHARSET_UTF_8)) { save(printWriter); } } /** * Parses an XML DOM element and loads it into a relationship. * * @param anElement DOM element. * * @throws java.io.IOException I/O related exception. */ @Override public void load(Element anElement) throws IOException { Node nodeItem; Attr nodeAttr; Element nodeElement; DataBagXML dataBagXML; DocumentXML documentXML; String nodeName, nodeValue; mRelationship.reset(); String attrValue = anElement.getAttribute("type"); if (StringUtils.isEmpty(attrValue)) throw new IOException("Relationship is missing type attribute."); mRelationship.setType(attrValue); NamedNodeMap namedNodeMap = anElement.getAttributes(); int attrCount = namedNodeMap.getLength(); for (int attrOffset = 0; attrOffset < attrCount; attrOffset++) { nodeAttr = (Attr) namedNodeMap.item(attrOffset); nodeName = nodeAttr.getNodeName(); nodeValue = nodeAttr.getNodeValue(); if (StringUtils.isNotEmpty(nodeValue)) { if ((!StringUtils.equalsIgnoreCase(nodeName, "type"))) mRelationship.addFeature(nodeName, nodeValue); } } NodeList nodeList = anElement.getChildNodes(); for (int i = 0; i < nodeList.getLength(); i++) { nodeItem = nodeList.item(i); if (nodeItem.getNodeType() != Node.ELEMENT_NODE) continue; nodeName = nodeItem.getNodeName(); if (nodeName.equalsIgnoreCase(IO.XML_PROPERTIES_NODE_NAME)) { nodeElement = (Element) nodeItem; dataBagXML = new DataBagXML(); dataBagXML.load(nodeElement); mRelationship.setBag(dataBagXML.getBag()); } else { nodeElement = (Element) nodeItem; documentXML = new DocumentXML(); documentXML.load(nodeElement); mRelationship.add(documentXML.getDocument()); } } } /** * Parses an XML DOM element and loads it into a bag/table. * * @param anIS Input stream. * * @throws java.io.IOException I/O related exception. * @throws javax.xml.parsers.ParserConfigurationException XML parser related exception. * @throws org.xml.sax.SAXException XML parser related exception. */ @Override public void load(InputStream anIS) throws ParserConfigurationException, IOException, SAXException, TransformerException { DocumentBuilderFactory docBldFactory = DocumentBuilderFactory.newInstance(); DocumentBuilder docBuilder = docBldFactory.newDocumentBuilder(); InputSource inputSource = new InputSource(anIS); Document xmlDocument = docBuilder.parse(inputSource); xmlDocument.getDocumentElement().normalize(); load(xmlDocument.getDocumentElement()); } /** * Parses an XML file identified by the path/file name parameter * and loads it into a bag/table. * * @param aPathFileName Absolute file name. * * @throws java.io.IOException I/O related exception. * @throws javax.xml.parsers.ParserConfigurationException XML parser related exception. * @throws org.xml.sax.SAXException XML parser related exception. */ @Override public void load(String aPathFileName) throws IOException, ParserConfigurationException, SAXException { File xmlFile = new File(aPathFileName); if (!xmlFile.exists()) throw new IOException(aPathFileName + ": Does not exist."); DocumentBuilderFactory docBldFactory = DocumentBuilderFactory.newInstance(); DocumentBuilder docBuilder = docBldFactory.newDocumentBuilder(); Document xmlDocument = docBuilder.parse(new File(aPathFileName)); xmlDocument.getDocumentElement().normalize(); load(xmlDocument.getDocumentElement()); } }