Java HTML / XML How to - Do XPath Evaluation

Question

We would like to know how to do XPath Evaluation.
Answer

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
//www  . j  av  a 2 s  .co m
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;

public class Main {
  public static void main(String[] args) throws Exception {
    XPathFactory xPathFactory = XPathFactory.newInstance();
    XPath xPath = xPathFactory.newXPath();

    InputSource doc = new InputSource(new InputStreamReader(
        new FileInputStream(new File("file.xml"))));

    String expression = "//Home/data";
    XPathExpression xPathExpression = xPath.compile(expression);

    NodeList elem1List = (NodeList) xPathExpression.evaluate(doc,
        XPathConstants.NODESET);
    xPathExpression = xPath.compile("@type");

    for (int i = 0; i < elem1List.getLength(); i++) {
      System.out.println(xPathExpression.evaluate(elem1List.item(i),
          XPathConstants.STRING));
    }
  }
}