Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.io.File;
import java.util.LinkedList;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class Main {

    public static void main(String[] args) throws Exception {
        DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
        Document doc = builder.parse(new File("test1.xml"));

        removeEmptyChildElements(doc.getDocumentElement());

        TransformerFactory transformerFactory = TransformerFactory.newInstance();
        Transformer transformer = transformerFactory.newTransformer();
        DOMSource source = new DOMSource(doc);
        StreamResult result = new StreamResult(new File("clean.xml"));
        transformer.transform(source, result);
    }

    private static void removeEmptyChildElements(Element parentElement) {
        List<Element> toRemove = new LinkedList<Element>();

        NodeList children = parentElement.getChildNodes();
        int childrenCount = children.getLength();
        for (int i = 0; i < childrenCount; ++i) {
            Node child = children.item(i);
            if (child.getNodeType() == Node.ELEMENT_NODE) {
                Element childElement = (Element) child;
                removeEmptyChildElements(childElement);
                if (elementIsRedundant(childElement)) {
                    toRemove.add(childElement);
                }
            }
        }

        for (Element childElement : toRemove) {
            parentElement.removeChild(childElement);
        }
        parentElement.normalize();
    }

    private static boolean elementIsRedundant(Element element) {
        if (element.hasAttributes())
            return false;
        if (!element.hasChildNodes())
            return true;
        NodeList children = element.getChildNodes();
        int childrenCount = children.getLength();
        for (int i = 0; i < childrenCount; ++i) {
            Node child = children.item(i);
            String value = child.getNodeValue();
            if (value != null && !value.matches("\\s*")) {
                return false; // Found non-whitespace text
            }
        }
        return true;
    }
}