Resolving "The markup in the document following the root element must be well-formed" Exception

Background

In last post we say how we can efficiently parse an XML file using DocumentBuilder -

Parsing XML files in Java using javax.xml.parsers.DocumentBuilder

But as we had concluded that post saying we cannot parse an XML file with multiple root elements. Hence in this post we will see how we can achieve that.

To The Code....

Let say now our data.xml file looks like the following - 

<data key="name" value="John"></data>
<data key="age" value="23"></data>
<data key="sex" value="male"></data>

That is no root element (or rather 3 root elements). If we run the previous code here we will get following Exception -

[Fatal Error] data.xml:2:2: The markup in the document following the root element must be well-formed.
Exception in thread "main" org.xml.sax.SAXParseException; systemId: file:/C:/Users/athakur/newJavaWorkspace/XMLParserDemo/data.xml; lineNumber: 2; columnNumber: 2; The markup in the document following the root element must be well-formed.
    at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(Unknown Source)
    at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(Unknown Source)
    at javax.xml.parsers.DocumentBuilder.parse(Unknown Source)
    at XMLParser.main(XMLParser.java:24)

Now lets see how can we tackle this. In this case we will take help of java.io.SequenceInputStream.

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.SequenceInputStream;
import java.util.Arrays;
import java.util.Collections;
import java.util.Enumeration;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

/**
 * 
 * @author athakur
 *
 */
public class XMLParser {
    
    public static void main(String args[]) throws IOException, ParserConfigurationException, SAXException
    {
        File file = new File("data.xml");
        DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
        Enumeration<InputStream> streams = Collections.enumeration(
                Arrays.asList(new InputStream[] {
                    new ByteArrayInputStream("<ROOT>".getBytes()),
                    new FileInputStream(file),
                    new ByteArrayInputStream("</ROOT>".getBytes()),
                }));

        SequenceInputStream sequenceStream = new SequenceInputStream(streams);
        Document doc = db.parse(sequenceStream);
        NodeList nodes = doc.getElementsByTagName("data");
        for ( int i = 0; i < nodes.getLength(); i++) 
        {
            Element element = (Element) nodes.item(i);
            String key = element.getAttribute("key");
            String value = element.getAttribute("value");    
            System.out.println("Key : " + key + " || Value : " + value);
        }
    }
}
 

and life is good again! Output is -

Key : name || Value : John
Key : age || Value : 23
Key : sex || Value : male 

Related Links

• Parsing XML files in Java using javax.xml.parsers.DocumentBuilder

Parsing XML files in Java using javax.xml.parsers.DocumentBuilder

Background

If you want to read xml files and process tag and attributes then there is a smarter way to do it than just reading the file line by line. That is exactly what we are going to see in this post.

To the Code.....

Assume we have the following data.xml file in the root directory of the project with following contents - 

<ROOT>
    <data key="name" value="John"></data>
    <data key="age" value="23"></data>
    <data key="sex" value="male"></data>
</ROOT>

Our goal is to parse this file and print key and value in an efficient manner. We do it the following way - 

import java.io.File;
import java.io.IOException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

/**
 * 
 * @author athakur
 *
 */
public class XMLParser {
    
    public static void main(String args[]) throws IOException, ParserConfigurationException, SAXException
    {
        File file = new File("data.xml");
        DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
        Document doc = db.parse(file);
        NodeList nodes = doc.getElementsByTagName("data");
        for ( int i = 0; i < nodes.getLength(); i++) 
        {
            Element element = (Element) nodes.item(i);
            String key = element.getAttribute("key");
            String value = element.getAttribute("value");    
            System.out.println("Key : " + key + " || Value : " + value);
        }
    }
}

and the output is as expected - 

Key : name || Value : John
Key : age || Value : 23
Key : sex || Value : male

Easy... wasn't it? Using DocumentBuilder makes parsing xml files easy.

NOTE : The XML file should have only one root element and can have multiple child elements. If this is not satisfied you will get following Exception

org.xml.sax.SAXParseException: The markup in the document following the root element must be well-formed.

In case of such cases (multiple root elements) how can we parse the XML? I have explained the same in separate post (See Related Links section below)

Parsing XML String

For parsing Simple XML strings you can do - 

import java.io.IOException;
import java.io.StringReader;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;


public class StringXMLParser {
    
    public static void main(String args[]) throws SAXException, IOException, ParserConfigurationException {
        
            String xmlString = "<records><employee><name>Aniket</name><title>Software Developer</title></employee></records>";
            
            DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
            Document doc = db.parse(new InputSource(new StringReader(xmlString)));
            
            NodeList nodes = doc.getElementsByTagName("employee");

            for (int i = 0; i < nodes.getLength(); i++) {
              Element element = (Element) nodes.item(i);

              NodeList name = element.getElementsByTagName("name");
              Element line = (Element) name.item(0);
              System.out.println("Name: " + line.getFirstChild().getNodeValue());

              NodeList title = element.getElementsByTagName("title");
              line = (Element) title.item(0);
              System.out.println("Title: " + line.getFirstChild().getNodeValue());
            }
    }
}

Related Links

• Resolving "The markup in the document following the root element must be well-formed" Exception