DOMEdit.java Source code

Introduction

Here is the source code for DOMEdit.java

Source

import java.io.IOException;

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

import org.w3c.dom.Attr;
import org.w3c.dom.CDATASection;
import org.w3c.dom.Comment;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.ProcessingInstruction;
import org.w3c.dom.Text;
import org.xml.sax.ErrorHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

public class DOMEdit {
    static public void main(String[] arg) {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        dbf.setValidating(true);
        dbf.setNamespaceAware(true);
        dbf.setIgnoringElementContentWhitespace(true);

        Document doc = null;
        try {
            DocumentBuilder builder = dbf.newDocumentBuilder();
            builder.setErrorHandler(new MyErrorHandler());
            InputSource is = new InputSource("personWithDTD.xml");
            doc = builder.parse(is);

            findByID(doc, "B");

            write(doc);
        } catch (Exception e) {
            System.err.println(e);
        }
    }

    public static void findByID(Document doc, String idName) {
        Element name = doc.getElementById(idName);
        if (name == null) {
            System.out.println("There is no element with the ID " + idName);
        } else {
            Text text = (Text) name.getFirstChild();
            System.out.println("The ID " + idName + " locates the name " + text.getData());
        }
    }

    private static final String TAB = "    ";

    private static void write(Document doc) throws IOException {
        outputHeading(doc);
        outputElement(doc.getDocumentElement(), "");
    }

    private static void outputHeading(Document doc) {
        System.out.print("<?xml version=\"1.0\"");
        DocumentType doctype = doc.getDoctype();
        if (doctype != null) {
            if ((doctype.getPublicId() == null) && (doctype.getSystemId() == null)) {
                System.out.println(" standalone=\"yes\"?>");
            } else {
                System.out.println(" standalone=\"no\"?>");
            }
        } else {
            System.out.println("?>");
        }
    }

    private static void outputElement(Element node, String indent) {
        System.out.print(indent + "<" + node.getTagName());
        NamedNodeMap nm = node.getAttributes();
        for (int i = 0; i < nm.getLength(); i++) {
            Attr attr = (Attr) nm.item(i);
            System.out.print(" " + attr.getName() + "=\"" + attr.getValue() + "\"");
        }
        System.out.println(">");
        NodeList list = node.getChildNodes();
        for (int i = 0; i < list.getLength(); i++)
            outputloop(list.item(i), indent + TAB);
        System.out.println(indent + "</" + node.getTagName() + ">");
    }

    private static void outputText(Text node, String indent) {
        System.out.println(indent + node.getData());
    }

    private static void outputCDATASection(CDATASection node, String indent) {
        System.out.println(indent + node.getData());
    }

    private static void outputComment(Comment node, String indent) {
        System.out.println(indent + "<!-- " + node.getData() + " -->");
    }

    private static void outputProcessingInstructionNode(ProcessingInstruction node, String indent) {
        System.out.println(indent + "<?" + node.getTarget() + " " + node.getData() + "?>");
    }

    private static void outputloop(Node node, String indent) {
        switch (node.getNodeType()) {
        case Node.ELEMENT_NODE:
            outputElement((Element) node, indent);
            break;
        case Node.TEXT_NODE:
            outputText((Text) node, indent);
            break;
        case Node.CDATA_SECTION_NODE:
            outputCDATASection((CDATASection) node, indent);
            break;
        case Node.COMMENT_NODE:
            outputComment((Comment) node, indent);
            break;
        case Node.PROCESSING_INSTRUCTION_NODE:
            outputProcessingInstructionNode((ProcessingInstruction) node, indent);
            break;
        default:
            System.out.println("Unknown node type: " + node.getNodeType());
            break;
        }
    }
}

class MyErrorHandler implements ErrorHandler {
    public void warning(SAXParseException e) throws SAXException {
        show("Warning", e);
        throw (e);
    }

    public void error(SAXParseException e) throws SAXException {
        show("Error", e);
        throw (e);
    }

    public void fatalError(SAXParseException e) throws SAXException {
        show("Fatal Error", e);
        throw (e);
    }

    private void show(String type, SAXParseException e) {
        System.out.println(type + ": " + e.getMessage());
        System.out.println("Line " + e.getLineNumber() + " Column " + e.getColumnNumber());
        System.out.println("System ID: " + e.getSystemId());
    }
}