DOMEdit.java Source code

Introduction

Here is the source code for DOMEdit.java

Source

    /*
    Code revised from
    Java, XML, and JAXP by Arthur Griffith John Wiley & Sons 2002
    
    */

    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);

                newEmail(doc, "B D", "newEmail");

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

        public static void newEmail(Document doc, String newname, String newemail) {
            Element root = doc.getDocumentElement();
            Element person = (Element) root.getFirstChild();
            while (person != null) {
                Element name = (Element) person.getFirstChild();
                Text nametext = (Text) name.getFirstChild();
                String oldname = nametext.getData();
                if (oldname.equals(newname)) {
                    Element email = (Element) name.getNextSibling();
                    Text emailtext = (Text) email.getFirstChild();
                    emailtext.setData(newemail);
                }
                person = (Element) person.getNextSibling();
            }
        }

        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());
        }
    }

    //File: personWithDTD.xml
    <?xml version="1.0"standalone="yes"?>

    <!--
    This document
    is both
    well formed
    and valid-->

    <!DOCTYPE folks[<!ELEMENT folks (person)*>
<!ELEMENT person (name, phone, email)>
<!ELEMENT name (#PCDATA)>
<!ELEMENT phone (#PCDATA)>
<!ELEMENT email (#PCDATA)>
]>

<folks>
    <person>
        <name>B D</name>
        <phone>999 555-8888</phone>
        <email>b@xyz.net</email>
    </person>
</folks>