Java如何解析xml类型的字符串，获取XPATH的值。

• 创建包含引用 XML 字符串的 StringReader 的 org.xml.sax.InputSource。
• 从 XPathFactory创建 XPath。
• 使用 xpath.evaluate('expression', inputSource)获取结果 HTML。

package com.onitroad.demo;
import java.io.StringReader;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
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.Document;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
public class XPathExample 
{
	public static void main(String[] args) throws Exception 
	{
		String xml = "<employees>"
					+ "<employee id=\"1\">"
						+ "<firstName>JackLi</firstName>"
						+ "<lastName>Gupta</lastName>"
						+ "<department><id>101</id><name>IT</name></department>"
					+ "</employee>"
				   + "</employees>";

		InputSource inputXML = new InputSource( new StringReader( xml ) );

        XPath xPath = XPathFactory.newInstance().newXPath();

        String result = xPath.evaluate("/employees/employee/firstName", inputXML);
        System.out.println(result);
    }
}