import org.xml.sax.*;
import org.xml.sax.helpers.DefaultHandler;
import javax.xml.parsers.*;
import java.io.*;

public class ch12_10 extends DefaultHandler 
{
    static String displayStrings[] = new String[1000];
    static int numberDisplayLines = 0;
    static String indent = "";

    public void displayDocument(String uri) 
    {
        DefaultHandler handler = this;
        SAXParserFactory factory = SAXParserFactory.newInstance();
        try {
            SAXParser saxParser = factory.newSAXParser();
            saxParser.parse(new File(uri), handler);
        } catch (Throwable t) {}
    } 

    public void startDocument() 
    {
        displayStrings[numberDisplayLines] = indent;
        displayStrings[numberDisplayLines] += "<?xml version=\"1.0\" encoding=\""+
            "UTF-8" + "\"?>";
        numberDisplayLines++;
    } 

    public void processingInstruction(String target, String data) 
    {
        displayStrings[numberDisplayLines] = indent;
        displayStrings[numberDisplayLines] += "<?";
        displayStrings[numberDisplayLines] += target;
        if (data != null && data.length() > 0) {
            displayStrings[numberDisplayLines] += ' ';
            displayStrings[numberDisplayLines] += data;
        }
        displayStrings[numberDisplayLines] += "?>";
        numberDisplayLines++;
    } 

    public void startElement(String uri, String localName, String qualifiedName, 
        Attributes attributes) 
    {
        displayStrings[numberDisplayLines] = indent;
        
        indent += "    ";

        displayStrings[numberDisplayLines] += '<';
        displayStrings[numberDisplayLines] += qualifiedName;
        if (attributes != null) {
            int numberAttributes = attributes.getLength();
            for (int loopIndex = 0; loopIndex < numberAttributes; loopIndex++) {
                displayStrings[numberDisplayLines] += ' ';
                displayStrings[numberDisplayLines] += attributes.getLocalName(loopIndex);
                displayStrings[numberDisplayLines] += "=\"";
                displayStrings[numberDisplayLines] += attributes.getValue(loopIndex);
                displayStrings[numberDisplayLines] += '"';
            }
        }
        displayStrings[numberDisplayLines] += '>';
        numberDisplayLines++;
    } 

    public void characters(char characters[], int start, int length) 
    {
        String characterData = (new String(characters, start, length)).trim();
        if(characterData.indexOf("\n") < 0 && characterData.length() > 0) {
            displayStrings[numberDisplayLines] = indent;
            displayStrings[numberDisplayLines] += characterData;
            numberDisplayLines++;
        }
    } 

    public void ignorableWhitespace(char characters[], int start, int length) 
    {
        //characters(characters, start, length); 
    } 

    public void endElement(String uri, String localName, String qualifiedName) 
    {
        indent = indent.substring(0, indent.length() - 4);
        displayStrings[numberDisplayLines] = indent;
        displayStrings[numberDisplayLines] += "</";
        displayStrings[numberDisplayLines] += qualifiedName;
        displayStrings[numberDisplayLines] += '>';
        numberDisplayLines++;

        if (qualifiedName.equals("FIRST_NAME")) {
            startElement("", "MIDDLE_NAME", "MIDDLE_NAME", null);
            characters("XML".toCharArray(), 0, "XML".length());
            endElement("", "MIDDLE_NAME", "MIDDLE_NAME");
        }
    } 

    public void warning(SAXParseException exception) 
    {
        System.err.println("WARNING! " +
            exception.getMessage());
    }

    public void error(SAXParseException exception) 
    {
        System.err.println("ERROR! " +
            exception.getMessage());
    }

    public void fatalError(SAXParseException exception)  
    {
        System.err.println("FATAL ERROR! " +
            exception.getMessage());
    }

    public static void main(String args[]) 
    {
        ch12_10 obj = new ch12_10();
        obj.displayDocument(args[0]);

        try {
            FileWriter filewriter = new FileWriter("ch12_11.xml");

            for(int loopIndex = 0; loopIndex < numberDisplayLines; loopIndex++){
                filewriter.write(displayStrings[loopIndex].toCharArray());
                filewriter.write('\n');
            }

            filewriter.close();
        } 
        catch (Exception e) {
            e.printStackTrace(System.err);
        }
    } 
}