CFDFactory.java

/*
 *  Copyright 2012 BigData.mx
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package mx.bigdata.sat.common;

import java.io.ByteArrayInputStream;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;

public abstract class CFDFactory {
  
  protected static String getVersion(byte[] data) throws Exception {
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder builder = factory.newDocumentBuilder();
    Document doc = builder.parse(new ByteArrayInputStream(data));
    XPathFactory xfactory = XPathFactory.newInstance();
    XPath xpath = xfactory.newXPath();
    return (String) xpath.evaluate("/Comprobante/@version", doc);
  }
}