Thread: read xml files and write to the txt file

Hi,
My background is mainframe and i'm new to java. We're moving from mainframe to the java world and i'm trying to achieve a task. I have a main folder and then bunch of sub folders and each sub folder has bunch of xml files, files size are varies some of them are 900kb. I need to read these xml files and send the output to the txt file (comma separated). I would really appreciate if someone can put me on the right track and advise me some possible options or even sample example would be great. please find below the sample xml file. I need to extract information's only where FORM name="F00001".

<PACKET>
   <FORM name="F00001" sequence="0">
      <FIELD sequence="1">02</FIELD>
      <FIELD sequence="2">00000</FIELD>
      <FIELD sequence="3">CAB100</FIELD>
      <FIELD sequence="4">TEFAP001</FIELD>
      <FIELD sequence="5">EMPTY FIELD</FIELD>
      <FIELD sequence="6">009.999.989</FIELD>
      <FIELD sequence="7">03</FIELD>
      <FIELD sequence="8">P9999999999999</FIELD>
      <FIELD sequence="9">EMPTY FIELD</FIELD>
      <FIELD sequence="10">EMPTY FIELD</FIELD>
   </FORM>
   <FORM name="F99999" sequence="1"
      <FIELD sequence="1">TIM K.</FIELD>
      <FIELD sequence="2">PROFESSOR</FIELD>
      <FIELD sequence="3">DAVID P. PIT</FIELD>
      <FIELD sequence="4">ASST PROFESSOR</FIELD>
      <FIELD sequence="5">EMPTY FIELD</FIELD>
      <FIELD sequence="6">009.999.989</FIELD>
      <FIELD sequence="7">03</FIELD>
      <FIELD sequence="8">P9999999999999</FIELD>
      <FIELD sequence="9">EMPTY FIELD</FIELD>
      <FIELD sequence="10">EMPTY FIELD</FIELD>
   </FORM>
</PACKET>
<PACKET>
   <FORM name="F00001" sequence="0">
      <FIELD sequence="1">09</FIELD>
      <FIELD sequence="2">00999</FIELD>
      <FIELD sequence="3">CAB101</FIELD>
      <FIELD sequence="4">TEFAP9999</FIELD>
      <FIELD sequence="5">EMPTY FIELD</FIELD>
      <FIELD sequence="6">009.999.999</FIELD>
      <FIELD sequence="7">03</FIELD>
      <FIELD sequence="8">T9999999999999</FIELD>
      <FIELD sequence="9">EMPTY FIELD</FIELD>
      <FIELD sequence="10">EMPTY FIELD</FIELD>
   </FORM>
   <FORM name="F99998" sequence="1"
      <FIELD sequence="1">KIM T.</FIELD>
      <FIELD sequence="2">PROFESSOR</FIELD>
      <FIELD sequence="3">NATHAN B.</FIELD>
      <FIELD sequence="4">ASST PROFESSOR</FIELD>
      <FIELD sequence="5">EMPTY FIELD</FIELD>
      <FIELD sequence="6">009.999.989</FIELD>
      <FIELD sequence="7">08</FIELD>
      <FIELD sequence="8">P9999999999988</FIELD>
      <FIELD sequence="9">EMPTY FIELD</FIELD>
      <FIELD sequence="10">EMPTY FIELD</FIELD>
   </FORM>
</PACKET>

Thank you so much

best regards
rm

You can use either JAXP or JAXB API. Using JAXP you will parse xml documents and build text file on the fly. Using JAXB, you can convert xml data into java objects. Then you print objects using comma separated values to text files.

If you want you can try Camel fraemwork. This framework is complex and will need time to be mastered. But once you master it your task reduces to few lines of code compared to several lines when JAXP/JAXB are used.

Thanks,
Syed.

Thanks for the reply, appreciate it.

I'm using xpath to parse the data. I need to read multiple input files from the folder i.e. c:/java/, can somoneplease help me.

import java.io.IOException;
import org.w3c.dom.*;
import org.xml.sax.SAXException;
import javax.xml.parsers.*;
import javax.xml.xpath.*;
 
public class XPathExample {
 
	public static void main(String[] args) throws ParserConfigurationException,
			SAXException, IOException, XPathExpressionException {
 
		DocumentBuilderFactory domFactory = DocumentBuilderFactory
				.newInstance();
		domFactory.setNamespaceAware(true); 
		DocumentBuilder builder = domFactory.newDocumentBuilder();
		Document doc = builder.parse("c:/java/test.xml");
 
		XPathFactory factory = XPathFactory.newInstance();
		XPath xpath = factory.newXPath();
		XPathExpression expr = xpath.compile("//FORM[@name='F00001']/*/text()");
 
		Object result = expr.evaluate(doc, XPathConstants.NODESET);
		NodeList nodes = (NodeList) result;
		for (int i = 0; i < nodes.getLength(); i++) {
			System.out.println(nodes.item(i).getNodeValue());
		}
 
	}
 
}

Thanks
rm

Originally Posted by syedbhai

You can use either JAXP or JAXB API. Using JAXP you will parse xml documents and build text file on the fly. Using JAXB, you can convert xml data into java objects. Then you print objects using comma separated values to text files.

If you want you can try Camel fraemwork. This framework is complex and will need time to be mastered. But once you master it your task reduces to few lines of code compared to several lines when JAXP/JAXB are used.

Thanks,
Syed.

Hi Syed,

Can you please help me with Camel example how to convert XML file to FlatFile.

Thanks
Jasleen