Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 Copyright (c) 2009-2011 Olivier Chafik, All Rights Reserved
    
 This file is part of JNAerator (http://jnaerator.googlecode.com/).
    
 JNAerator 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.
    
 JNAerator 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 JNAerator.  If not, see <http://www.gnu.org/licenses/>.
 */

import java.lang.ref.SoftReference;
import java.util.LinkedHashMap;

import java.util.Map;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class Main {
    public static Map<String, SoftReference<XPathExpression>> xPathExpressionsCache = new LinkedHashMap<String, SoftReference<XPathExpression>>();
    private static SoftReference<XPath> sharedXPath;

    public static Node findNodeByXPath(String xPathString, Object source) throws XPathExpressionException {
        NodeList list = (NodeList) getXPathExpression(xPathString).evaluate(source, XPathConstants.NODESET);
        int len = list.getLength();
        return len == 0 ? null : list.item(0);
    }

    public static XPathExpression getXPathExpression(String xPathString) throws XPathExpressionException {
        SoftReference<XPathExpression> ref = xPathExpressionsCache.get(xPathString);
        XPathExpression expression = ref == null ? null : ref.get();
        if (expression == null)
            xPathExpressionsCache.put(xPathString,
                    new SoftReference<XPathExpression>(expression = getSharedXPath().compile(xPathString)));

        return expression;
    }

    public static XPath getSharedXPath() {
        XPath xPath = null;
        if (sharedXPath != null)
            xPath = sharedXPath.get();
        if (xPath == null) {
            XPathFactory xPathFactory = XPathFactory.newInstance();
            sharedXPath = new SoftReference<XPath>(xPath = xPathFactory.newXPath());
        }
        return xPath;
    }
}