XMLStreamWriter Dekorator mit Logging

import java.util.Stack;

import javax.xml.namespace.NamespaceContext;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;

import org.apache.commons.lang.StringUtils;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

/**
 * Decorator mit Logging der Operationen.
 * 
 * @author Serhat Cinar
 */
public class LoggingXMLStreamWriter implements XMLStreamWriter {
    private static final Logger LOG = LogManager.getLogger(LoggingXMLStreamWriter.class);

    private final XMLStreamWriter delegate;
    private int indent = 0;
    private final Stack<String> elements = new Stack<>();

    public LoggingXMLStreamWriter(final XMLStreamWriter delegate) {
        this.delegate = delegate;
    }

    @Override
    public void writeStartElement(final String localName) throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "start: " + localName);
        elements.push(localName);
        delegate.writeStartElement(localName);
        indent++;
    }

    @Override
    public void writeStartElement(final String namespaceURI, final String localName) throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "start: " + localName);
        elements.push(localName);
        delegate.writeStartElement(namespaceURI, localName);
        indent++;
    }

    @Override
    public void writeStartElement(final String prefix, final String localName, final String namespaceURI) throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "start: " + prefix + ":" + localName);
        elements.push(localName);
        delegate.writeStartElement(prefix, localName, namespaceURI);
        indent++;
    }

    @Override
    public void writeEmptyElement(final String namespaceURI, final String localName) throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "empty: " + localName);
        delegate.writeEmptyElement(namespaceURI, localName);
    }

    @Override
    public void writeEmptyElement(final String prefix, final String localName, final String namespaceURI) throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "empty: " + prefix + ":" + localName);
        delegate.writeStartElement(prefix, localName, namespaceURI);
    }

    @Override
    public void writeEmptyElement(final String localName) throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "empty: " + localName);
        delegate.writeStartElement(localName);
    }

    @Override
    public void writeEndElement() throws XMLStreamException {
        indent--;
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "end (" + elements.pop() + ")");
        delegate.writeEndElement();
    }

    @Override
    public void writeEndDocument() throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "end document");
        delegate.writeEndDocument();
    }

    @Override
    public void close() throws XMLStreamException {
        delegate.close();
    }

    @Override
    public void flush() throws XMLStreamException {
        delegate.flush();
    }

    @Override
    public void writeAttribute(final String localName, final String value) throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "attribute: " + localName + "=" + value);
        delegate.writeAttribute(localName, value);
    }

    @Override
    public void writeAttribute(final String prefix, final String namespaceURI, final String localName, final String value) throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "attribute: " + prefix + ":" + localName + "=" + value);
        delegate.writeAttribute(prefix, namespaceURI, localName, value);
    }

    @Override
    public void writeAttribute(final String namespaceURI, final String localName, final String value) throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "attribute: " + localName + "=" + value);
        delegate.writeAttribute(namespaceURI, localName, value);
    }

    @Override
    public void writeNamespace(final String prefix, final String namespaceURI) throws XMLStreamException {
        delegate.writeNamespace(prefix, namespaceURI);
    }

    @Override
    public void writeDefaultNamespace(final String namespaceURI) throws XMLStreamException {
        delegate.writeDefaultNamespace(namespaceURI);
    }

    @Override
    public void writeComment(final String data) throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "comment: " + data);
        delegate.writeComment(data);
    }

    @Override
    public void writeProcessingInstruction(final String target) throws XMLStreamException {
        delegate.writeProcessingInstruction(target);
    }

    @Override
    public void writeProcessingInstruction(final String target, final String data) throws XMLStreamException {
        delegate.writeProcessingInstruction(target, data);
    }

    @Override
    public void writeCData(final String data) throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "cdata: " + data);
        delegate.writeCData(data);
    }

    @Override
    public void writeDTD(final String dtd) throws XMLStreamException {
        delegate.writeDTD(dtd);
    }

    @Override
    public void writeEntityRef(final String name) throws XMLStreamException {
        delegate.writeEntityRef(name);
    }

    @Override
    public void writeStartDocument() throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "start document");
        delegate.writeStartDocument();
    }

    @Override
    public void writeStartDocument(final String version) throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "start document v" + version);
        delegate.writeStartDocument(version);
    }

    @Override
    public void writeStartDocument(final String encoding, final String version) throws XMLStreamException {
        LOG.debug(StringUtils.repeat(" ", indent * 2) + "start document v" + version + ", enc=" + encoding);
        delegate.writeStartDocument(encoding, version);
    }

    @Override
    public void writeCharacters(final String text) throws XMLStreamException {
        delegate.writeCharacters(text);
    }

    @Override
    public void writeCharacters(final char[] text, final int start, final int len) throws XMLStreamException {
        delegate.writeCharacters(text, start, len);
    }

    @Override
    public String getPrefix(final String uri) throws XMLStreamException {
        return delegate.getPrefix(uri);
    }

    @Override
    public void setPrefix(final String prefix, final String uri) throws XMLStreamException {
        delegate.setPrefix(prefix, uri);
    }

    @Override
    public void setDefaultNamespace(final String uri) throws XMLStreamException {
        delegate.setDefaultNamespace(uri);
    }

    @Override
    public void setNamespaceContext(final NamespaceContext context) throws XMLStreamException {
        delegate.setNamespaceContext(context);
    }

    @Override
    public NamespaceContext getNamespaceContext() {
        return delegate.getNamespaceContext();
    }

    @Override
    public Object getProperty(final String name) throws IllegalArgumentException {
        return delegate.getProperty(name);
    }

}