XMLReader.java

package coverage;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.TransformerException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;


public class XMLReader implements XMLCoverage {

	public XMLReader() {

	}
	
	public Coverage readFromFile(File file) throws ParserConfigurationException, TransformerException, IOException, SAXException, UnsupportedCoverageException  {
		
		String fileName = file.getPath();
		InputStream inputStream = null;
		inputStream = new FileInputStream(fileName);
		return readXML(inputStream);
	}
	
	public Coverage readXML(InputStream xmlContent) throws ParserConfigurationException, TransformerException, IOException, SAXException, UnsupportedCoverageException {
		Document doc = parse(xmlContent);
		return getCoverage(doc);
	}
	
	
	public Coverage readXML(String xmlContent) throws ParserConfigurationException, TransformerException, IOException, SAXException, UnsupportedCoverageException {
		Document doc = parse(xmlContent);
		return getCoverage(doc);
	}

	private Coverage getCoverage(Document doc) throws NumberFormatException, UnsupportedCoverageException {
		Coverage coverage = new Coverage(); 
		for (Element rootNode : getElements(doc.getElementsByTagName(ROOT))) {
			coverage.setType(rootNode.getAttribute(TYPE));
			coverage.setBaseValue(Integer.valueOf(rootNode.getAttribute(BASE)));
			break;
		}
		for (Element fileNode : getElements(doc.getElementsByTagName(FILE))) {
			getCoverage(coverage, fileNode);
		}
		return coverage;
	}
	
	
	private void getCoverage(Coverage coverage, Element fileNode) throws UnsupportedCoverageException {
		
		String fileName = fileNode.getAttribute(FILE_NAME);
		Element coverageNode = getElements(fileNode.getElementsByTagName(COVERAGE_KEY)).get(0);
		for (Element line : getElements(coverageNode.getElementsByTagName(COVERED_LINE))) {
			try {
				if (line.hasAttribute(THIS)) {
					coverage.setLineCovered(fileName, Integer.valueOf(line.getAttribute(THIS)), Integer.valueOf(line.getAttribute(INTERACTION)), line.getAttribute(TEXT));
				} else {
					throwError("Unknown attribute " + line.getNodeName(), line);
				}
			} catch (Exception e) {
				throwError("Parse error occured " + e.getMessage(), line);
			}
		}
	}

	private Document parse(String input) throws IOException, SAXException, ParserConfigurationException {
		InputStream stream = new ByteArrayInputStream(input.getBytes(StandardCharsets.UTF_8));
		return parse(stream);
	}

	private Document parse(InputStream stream) throws IOException, SAXException, ParserConfigurationException {
		Document doc = PositionalXMLReader.readXML(stream);
		doc.getDocumentElement().normalize();
		return doc;
	}
	
	/**
	 * @param nodeList
	 * @return The child nodes from type Element of the given NodeList. 
	 */
	private ArrayList<Element> getElements(NodeList nodeList) {
		ArrayList<Element> elements = new ArrayList<Element>(nodeList.getLength());
		for (int temp = 0; temp < nodeList.getLength(); temp++) {
			org.w3c.dom.Node nNode = nodeList.item(temp);
			if (nNode.getNodeType() == org.w3c.dom.Node.ELEMENT_NODE) {
				Element eElement = (Element) nNode;
				elements.add(eElement);
			}
		}
		return elements;
	}
	
	/**
	 * Throws an error that will be used for error markers
	 * @param message The error message
	 * @param tempNode The node that causes the error. this node is used for positioning. 
	 * @throws UnsupportedCoverageException 
	 * @throws NumberFormatException 
	 */
	private void throwError(String message, org.w3c.dom.Node node) throws NumberFormatException, UnsupportedCoverageException {
		throw new UnsupportedCoverageException(message, Integer.parseInt (node.getUserData(PositionalXMLReader.LINE_NUMBER_KEY_NAME).toString()));
	}
}