example working with XPath API

Step-1:

package com;

import java.io.IOException;

import java.io.StringReader;

import javax.xml.namespace.NamespaceContext;

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.xml.sax.InputSource;

import org.xml.sax.SAXException;

public class XpathExtractor {

      

      

       private static int MAX_BUFFER_SIZE = 16384;

       private NamespaceContext namespaceResolver;

       private XPath xpath;

       private DocumentBuilder builder;

       private DocumentBuilderFactory domFactory;

      

       private String  itemIdXPath;

       private String  shipDateXPath;

      

      

       private XPathExpression  itemIdXPathExpression;

       private XPathExpression  shipDateXPathExpression;

      

      

       public CopyOfInstntInvExtractor() {

              xpath = XPathFactory.newInstance().newXPath();

              domFactory = DocumentBuilderFactory.newInstance();

          

       }

      

       public NamespaceContext getNamespaceResolver() {

              return namespaceResolver;

       }

       public void setNamespaceResolver(NamespaceContext namespaceResolver) {

              this.namespaceResolver = namespaceResolver;

       }

      

       public String getItemIdXPath() {

              return itemIdXPath;

       }

       public void setItemIdXPath(String itemIdXPath) {

              this.itemIdXPath = itemIdXPath;

              this.itemIdXPathExpression = this.compile(this.itemIdXPath);

              }

      

      

      

       public String getShipDateXPath() {

              return shipDateXPath;

       }

       public void setShipDateXPath(String shipDateXPath) {

              this.shipDateXPath = shipDateXPath;

              this.shipDateXPathExpression= this.compile(this.shipDateXPath);

       }

      

      

      

       public void  getInfo(String message) throws Exception

       {

             

              try {

                          

                           builder = domFactory.newDocumentBuilder();

      

                         Document doc = builder.parse( new InputSource(new StringReader(message)));

                        

                      

                      String itemID = (String) this.itemIdXPathExpression.evaluate(doc, XPathConstants.STRING);

                    

                         String shipDate = (String) this.shipDateXPathExpression.evaluate(doc, XPathConstants.STRING);

                        

                    

             

                    

              } catch (SAXException e) {

                     throw e;

                    

              } catch (IOException e) {

                     throw e;

                    

              } catch (XPathExpressionException e) {

                     throw e;

              }

                    

       }

      

      

      

       private XPathExpression compile(String expression){                 

              try {

                     return this.xpath.compile( expression );

                    

              } catch (XPathExpressionException e) {

                     String message = "Error compiling XPath Expression [" + expression + "]";

                     throw new RuntimeException(message, e);

              }

       }     

      

}

Step-2: Spring bean configuration:

<bean id="xpathExtractor" class="com. XpathExtractor ">   

       <property name="shipDateXPath"        value=" itemIdXPath”/>

       <property name="itemIdXPath"          value=" shipDate " />

 </bean>

Input :xml file

Input XML file as string for the method: getInfo (-)

<?xml version="1.0" encoding="UTF-8"?>

<functionEvent >

  <itemIdXPath>10000000860002</ itemIdXPath >

  <shipDate>2013-03-12</shipDate>

</ functionEvent >