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.field.data.DataBag; import com.nridge.core.base.field.data.DataField; 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 DataBagXML class provides XML helper methods. */ public class DataBagXML implements DOMInterface { private DataBag mBag; private boolean mIsSimple; private DataFieldXML mDataFieldXML; /** * Default constructor. */ public DataBagXML() { mBag = new DataBag(); mDataFieldXML = new DataFieldXML(); } /** * Constructor accepts a bag as a parameter. * * @param aBag Bag instance. */ public DataBagXML(DataBag aBag) { setBag(aBag); mDataFieldXML = new DataFieldXML(); } /** * Assigns the bag parameter to the internally managed bag instance. * * @param aBag Bag instance. */ public void setBag(DataBag aBag) { mBag = aBag; } /** * Returns a reference to the internally managed bag instance. * * @return Bag instance. */ public DataBag getBag() { return mBag; } /** * Assigns a simple format flag. * * @param anIsSimple Is output format simple? */ public void setIsSimpleFlag(boolean anIsSimple) { mIsSimple = anIsSimple; } /** * Saves the previous assigned bag/table (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 IOException I/O related exception. */ public void save(PrintWriter aPW, String aTagName, int anIndentAmount) throws IOException { IOXML.indentLine(aPW, anIndentAmount); String tagName = StringUtils.remove(aTagName, StrUtl.CHAR_SPACE); aPW.printf("<%s", tagName); if (!mIsSimple) { IOXML.writeAttrNameValue(aPW, "type", IO.extractType(mBag.getClass().getName())); IOXML.writeAttrNameValue(aPW, "name", mBag.getName()); IOXML.writeAttrNameValue(aPW, "title", mBag.getTitle()); IOXML.writeAttrNameValue(aPW, "count", mBag.count()); IOXML.writeAttrNameValue(aPW, "version", IO.DATABAG_XML_FORMAT_VERSION); } for (Map.Entry<String, String> featureEntry : mBag.getFeatures().entrySet()) IOXML.writeAttrNameValue(aPW, featureEntry.getKey(), featureEntry.getValue()); aPW.printf(">%n"); for (DataField dataField : mBag.getFields()) { if (dataField.isAssigned()) { mDataFieldXML.saveNode(aPW, anIndentAmount + 1); mDataFieldXML.saveAttr(aPW, dataField); mDataFieldXML.saveValue(aPW, dataField, anIndentAmount + 1); } } IOXML.indentLine(aPW, anIndentAmount); aPW.printf("</%s>%n", tagName); } /** * Saves the previous assigned bag/table (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, "DataBag", 0); } /** * Saves the previous assigned bag/table (e.g. via constructor or set method) * to the path/file name specified as a parameter. * * @param aPathFileName Absolute file name. * @param aTagName Tag name. * @throws java.io.IOException I/O related exception. */ public void save(String aPathFileName, String aTagName) throws IOException { try (PrintWriter printWriter = new PrintWriter(aPathFileName, StrUtl.CHARSET_UTF_8)) { save(printWriter, aTagName, 0); } } /** * Saves the previous assigned bag/table (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 bag/table. * * @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; DataField dataField; String nodeName, nodeValue; String className = mBag.getClass().getName(); String attrValue = anElement.getAttribute("type"); if ((StringUtils.isNotEmpty(attrValue)) && (!IO.isTypesEqual(attrValue, className))) throw new IOException("Unsupported type: " + attrValue); attrValue = anElement.getAttribute("name"); if (StringUtils.isNotEmpty(attrValue)) mBag.setName(attrValue); attrValue = anElement.getAttribute("title"); if (StringUtils.isNotEmpty(attrValue)) mBag.setTitle(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, "name")) || (StringUtils.equalsIgnoreCase(nodeName, "type")) || (StringUtils.equalsIgnoreCase(nodeName, "count")) || (StringUtils.equalsIgnoreCase(nodeName, "title")) || (StringUtils.equalsIgnoreCase(nodeName, "version"))) continue; else mBag.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_FIELD_NODE_NAME)) { nodeElement = (Element) nodeItem; dataField = mDataFieldXML.load(nodeElement); if (dataField != null) mBag.add(dataField); } } } /** * Parses an XML DOM element and loads it into a bag/table. * * @param anIS Input stream. * * @throws java.io.IOException I/O 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()); } }