Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
import javax.xml.xpath.*;
import org.w3c.dom.Node;

public class Main {
    private static XPathFactory xpathFactory = null;
    private static XPath xpath = null;

    /**
     * This method yields the Attribute at the node extracted by the expression.
     * @param parentNode The node to start at.
     * @param expression The XPath expression to evaluate.
     * @param attribute The Name of the attribute you would like to extract from the
     * XPath'd node.
     * @return The Value of the attribute, or the empty String if no matching node
     * or matching attribute could be found.
     * @throws XPathExpressionException
     *
     * @author <a href='mailto:intere@gmail.com'>Eric Internicola</a>
     */
    public static String getAttribute(Node parentNode, String expression, String attribute)
            throws XPathExpressionException {
        String attr = "";

        Node n = getNode(parentNode, expression);

        if (n != null) {
            n = n.getAttributes().getNamedItem(attribute);
        }

        if (n != null) {
            attr = n.getNodeValue();
        }

        return attr;
    }

    /**
     * This method uses XPath to get you a child node of the provided node.
     * @param parentNode The node to start at.
     * @param expression The XPath Expression to evaluate.
     * @return The Node that was retrieved by the provided node and xpath expression.
     * @throws XPathExpressionException
     *
     * @author <a href='mailto:intere@gmail.com'>Eric Internicola</a>
     */
    public static Node getNode(Node parentNode, String expression) throws XPathExpressionException {
        return (Node) getXPath().evaluate(expression, parentNode, XPathConstants.NODE);
    }

    /**
     * This method gives you an XPath object from the XPath Factory.
     * @return A new XPath object.
     *
     * @author <a href='mailto:intere@gmail.com'>Eric Internicola</a>
     */
    protected static synchronized XPath getXPath() {
        if (xpath == null) {
            xpath = getXPathFactory().newXPath();
        }

        return xpath;
    }

    /**
     * This method yields the XPath Factory (creating it if necessary).
     * @return The XPathFactory object.
     *
     * @author <a href='mailto:intere@gmail.com'>Eric Internicola</a>
     */
    protected static synchronized XPathFactory getXPathFactory() {
        if (xpathFactory == null) {
            xpathFactory = XPathFactory.newInstance();
        }

        return xpathFactory;
    }
}