import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.annotation.*;
import java.io.StringReader;
import java.io.StringWriter;
 
@XmlRootElement(name = "employee")
@XmlAccessorType(XmlAccessType.FIELD)
public class Employee
{
    public static void main(String args[]) throws JAXBException
    {
        final Employee john = new Employee();
        john.setId(1);
        john.setFirstName("John");
        john.setMiddleName("Robert");
        john.setLastName("Doe");
 
        // write it out as XML
        final JAXBContext jaxbContext = JAXBContext.newInstance(Employee.class);
        StringWriter writer = new StringWriter();
        jaxbContext.createMarshaller().marshal(john, writer);
 
        // read it from XML
        final Employee johnRead =
            (Employee) jaxbContext.createUnmarshaller().unmarshal(
                new StringReader(writer.toString()));
        if (john.equals(johnRead))
        {   // write the new object out as XML again.
            writer = new StringWriter();
            jaxbContext.createMarshaller().marshal(johnRead, writer);
            System.out.println(
                "johnRead was identical to john: \n" + writer.toString());
        }
        else
        {
            System.out.println("john and johnRead are not equal");
        }
    }
 
    @XmlAttribute
    private int id;
 
    /**
     * Employee's first name
     */
    @XmlElement
    private
    String firstName;
 
    /**
     * Employee's middle name
     */
    @XmlElement
    private
    String middleName;
 
    /**
     * Employee's last name
     */
    @XmlElement
    private
    String lastName;
 
    public Employee()
    {
    }
 
    public int getId()
    {
        return id;
    }
 
    public void setId(int id)
    {
        this.id = id;
    }
 
    public String getLastName()
    {
        return lastName;
    }
 
    public void setLastName(String lastName)
    {
        this.lastName = lastName;
    }
 
    public String getMiddleName()
    {
        return middleName;
    }
 
    public void setMiddleName(String middleName)
    {
        this.middleName = middleName;
    }
 
    public String getFirstName()
    {
        return firstName;
    }
 
    public void setFirstName(String firstName)
    {
        this.firstName = firstName;
    }
 
    @Override
    public boolean equals(Object o)
    {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
 
        Employee employee = (Employee) o;
 
        if (id != employee.id) return false;
        if (firstName != null ? !firstName.equals(employee.firstName) :
            employee.firstName != null) return false;
        if (lastName != null ? !lastName.equals(employee.lastName) :
            employee.lastName != null) return false;
        if (middleName != null ? !middleName.equals(employee.middleName) :
            employee.middleName != null) return false;
 
        return true;
    }
 
    @Override
    public int hashCode()
    {
        int result = id;
        result = 31 * result + (firstName != null ? firstName.hashCode() : 0);
        result = 31 * result + (middleName != null ? middleName.hashCode() : 0);
        result = 31 * result + (lastName != null ? lastName.hashCode() : 0);
        return result;
    }
 
    @Override
    public String toString()
    {
        return "Employee{" +
            "id=" + id +
            ", firstName='" + firstName + '\'' +
            ", middleName='" + middleName + '\'' +
            ", lastName='" + lastName + '\'' +
            '}';
    }
}

javac -classpath .:$(for jar in libs/*.jar; do echo -n "$jar:"; done) Employee.java
java -classpath .:$(for jar in libs/*.jar; do echo -n "$jar:"; done) Employee

johnRead was identical to john:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<employee id="1">
 <firstName>John</firstName>
 <middleName>Robert</middleName>
 <lastName>Doe</lastName>
</employee>

<textbox width="100%" height="1.2em" sclass="status" readonly="true"
         id="status" use="com.example.system.StatusBar" />
<timer id="statusTimer" running="false" repeats="false"
       onTimer='status.setText("");'/>

package com.example.system;
 
/**
 * Handles setting of status bar messages.  All calls to this object must be
 * done from within the ZK framework, such as inside an event.
 *
 * Hides the details of what component is actually a status bar.  It could be a
 * textbox, or something else, but we don't want to be dependant on any specific
 * type of control, in case it changes in the future.
 *
 * Created :  Jan 31, 2010 1:39:37 AM MST
 *
 * Modified : $Date$ UTC
 *
 * Revision : $Revision$
 *
 * @author Trenton D. Adams
 */
public interface IStatusBar
{
    /**
     * Sets the status bar text for the time period indicated.
     *
     * @param statusText status text
     * @param timePeriod delay in seconds, before the status bar will be
     *                   cleared.
     */
    public void setStatus(final String statusText, final int timePeriod);
 
    /**
     * Sets the status bar text.  Pass null to clear.
     *
     * @param statusText status text or null to clear
     */
    public void setStatus(final String statusText);
 
    /**
     * @return the status text of the status bar.
     */
    public String getStatus();
}

package com.example.system;
 
import org.apache.log4j.Logger;
import org.zkoss.zk.ui.Session;
import org.zkoss.zk.ui.ext.AfterCompose;
import org.zkoss.zul.Textbox;
import org.zkoss.zul.Timer;
 
/**
 * StatusBar handles setting the status bar text, and clearing it after a given
 * timeout.  Implements IStatusBar, to hide the details of what a status bar is
 * from the client code.  We use a textbox, but we could change that, who knows.
 *
 * Created :  Jan 31, 2010 12:42:29 AM MST
 *
 * Modified : $Date$ UTC
 *
 * Revision : $Revision$
 *
 * @author Trenton D. Adams
 */
public class StatusBar extends Textbox implements AfterCompose, IStatusBar
{
    @SuppressWarnings({"ConstantNamingConvention"})
    private static final Logger logger = Logger.getLogger(StatusBar.class);
 
    public StatusBar()
    {
    }
 
    public void afterCompose()
    {
        logger.info("status bar running as " + getId());
        // TODO find a better method, getFellow() didn't work
        final Session session = getDesktop().getSession();
        session.setAttribute("status", this);
    }
 
    public void setStatus(final String statusText, final int timePeriod)
    {
        setStatus(statusText);
        // the timer must be in the page, or the page is inactive and this
        // call would never happen?
        final Timer timer = (Timer) getFellow("statusTimer");
        timer.setDelay(timePeriod * 1000);
        timer.start();
    }
 
    public void setStatus(final String statusText)
    {
        setText(statusText);
    }
 
    public String getStatus()
    {
        return getText();
    }
}

final Session session = getDesktop().getSession();
final IStatusBar statusBar = (IStatusBar) session.getAttribute("status");
statusBar.setStatus("Transaction Posted", 5);

<error-page>
 <exception-type>java.lang.Throwable</exception-type>
 <location>/error.zul</location>
</error-page>

<?xml version="1.0" encoding="UTF-8"?>
<zk xmlns="http://www.zkoss.org/2005/zul"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.zkoss.org/2005/zul http://www.zkoss.org/2005/zul/zul.xsd">
  <window mode="modal" sizable="true"
          title="Error ${requesScope['javax.servlet.error.status_code']}">
    <vbox>
      <hbox>
        <include src="/jsp/error.jsp"/>
      </hbox>
      <hbox style="margin-left:auto; margin-right:auto; text-align: center;">
        <button label="Okay" onClick="spaceOwner.detach()"/>
        <button label="Reload Page" onClick="Executions.sendRedirect(null)"/>
      </hbox>
    </vbox>
  </window>
</zk>

<%@ page import="java.io.PrintWriter" %>
<%@ page import="java.io.StringWriter" %>
<%@ page import="com.example.util.Util" %>
<%@ page isErrorPage="true" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="ce" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
<%@ taglib uri="http://jakarta.apache.org/taglibs/string-1.1" prefix="st" %>
<!-- BEGIN error.jsp -->
<div class="error">
  <p class="message"><%=exception.getMessage()%></p>
 
  <p>An error has occured. If you believe this error is a system problem, and you
  continue to get this error, please contact a special person via
    <a href="mailto:'me@example.com' ">email</a>
  </p>
 
  <ce:if test="<%=Util.getBooleanItem(\"/debug\")%>">
    <%
      StringWriter sw = new StringWriter();
      PrintWriter pw = new PrintWriter(sw);
      exception.printStackTrace(pw);
    %>
    <ce:set var="exceptionStack"><%=sw.toString()%>
    </ce:set>
    <div class="debug">
      Message : <%=exception.getMessage()%>
      Exception : <%=exception.getClass().getName()%>
      Stack : ${fn:escapeXml(exceptionStack)}
    </div>
  </ce:if>
</div>
<!-- END error.jsp -->

<decimalbox use="com.example.common.LedgerDecimalBox" id="credit-0"/>

<decimalbox constraint="no negative,no zero" format="#,##0.#" scale="2"/>

package com.example.common;
 
import com.example.util.CVUtil;
import org.apache.log4j.Logger;
import org.zkoss.zk.ui.ext.AfterCompose;
import org.zkoss.zul.Decimalbox;
 
public class LedgerDecimalBox extends Decimalbox implements AfterCompose
{
    private static Logger logger = Logger.getLogger(LedgerDecimalBox.class);
    public LedgerDecimalBox()
    {   // load configured options
        setFormat(Util.getStringItem("/inputs/decimalbox/format"));
        setConstraint(Util.getStringItem("/inputs/decimalbox/constraints"));
        setScale(2);
    }
 
    public void afterCompose()
    {
        logger.info("id: " + getId());
    }
}

xmlSource = new StreamSource(
 new ByteArrayInputStream(((String) xml).getBytes()))
xsltSource =
 transFact.getAssociatedStylesheet(xmlSource, null, null, null);
...
trans.transform(xmlSource, result);

    /**
     * Runs a xalan transformation of the xml, with the specified xsl.
     *
     * @param xml        a String xml document, or a java.io.File object
     *                   pointing to the file
     * @param xsl        a String filename, or a java.io.File object pointing to
     *                   the file.  A null value indicates you want to resolve
     *                   the XML's "xml-stylesheet" processing instruction as
     *                   the XSL to use.  If it does not exist, it may fail.
     * @param parameters a map of parameters to pass to the XSL
     *
     * @return the String of the transformed xml
     *
     * @throws TransformerException if a transformation error occurs
     */
    public static String xalanTransformation(final Object xml, final Object xsl,
        final Map parameters)
        throws TransformerException, ParserConfigurationException, IOException,
        SAXException
    {
        // create an instance of TransformerFactory
        final ByteArrayOutputStream byteArray;
        final Result result;
        final TransformerFactory transFact;
        final Transformer trans;
        final Set keys;
        final Iterator keyIt;
        final ExceptionErrorListener errorListener;
 
        errorListener = new ExceptionErrorListener();
        byteArray = new ByteArrayOutputStream(BUFFER_CAPACITY);
        result = new StreamResult(byteArray);
        transFact = TransformerFactory.newInstance();
        transFact.setErrorListener(errorListener);
        final Source xmlSource;
        if (xml instanceof String)
        {
            final Document doc = stringToDocument((String) xml);
            logger.debug(documentToString(doc));
            xmlSource = new DOMSource(doc);
        }
        else if (xml instanceof File)
        {
            xmlSource = new StreamSource((File) xml);
        }
        else
        {
            throw new IllegalArgumentException(
                "Only java.lang.String and java.io.File xml are supported " +
                    "for the xml parameter");
        }
 
        final Source xsltSource;
 
        if (xsl == null)
        {   // grab the XSL defined by the XML's xml-stylesheet instruction
            xsltSource =
                transFact.getAssociatedStylesheet(xmlSource, null, null, null);
        }
        else if (xsl instanceof String)
        {
            final InputStream xsltResource = Util.class.getResourceAsStream(
                (String) xsl);
            if (xsltResource == null)
            {
                throw new IllegalArgumentException(
                    xsl + " is an invalid XSL file");
            }
            xsltSource = new StreamSource(xsltResource);
        }
        else if (xsl instanceof File)
        {
            xsltSource = new StreamSource((File) xsl);
        }
        else
        {
            throw new IllegalArgumentException(
                "Only java.lang.String xsl filenames, or java.io.File " +
                    "are supported for the xsl parameter");
        }
 
        trans = transFact.newTransformer(xsltSource);
        trans.setErrorListener(errorListener);
        keys = parameters.keySet();
        keyIt = keys.iterator();
        while (keyIt.hasNext())
        {
            final String key;
            key = (String) keyIt.next();    // assume string key
            trans.setParameter(key, parameters.get(key));
        }
        trans.transform(xmlSource, result);
        return byteArray.toString();
    }
 
    /**
     * Example for retrieving the APAS institutions list
     *
     * @param xml the string representation of the XML
     *
     * @return the Document object created from the XML string representation
     *
     * @throws IOException  if an I/O error occurs
     * @throws SAXException if an XML parsing exception occurs.
     */
    public static Document stringToDocument(final String xml)
        throws SAXException, IOException
    {
        return loadXMLFrom(new ByteArrayInputStream(xml.getBytes()));
    }
 
    public static Document loadXMLFrom(final InputStream is)
        throws SAXException, IOException
    {
        final DocumentBuilderFactory factory =
            DocumentBuilderFactory.newInstance();
        factory.setNamespaceAware(true);
        DocumentBuilder builder = null;
        try
        {
            builder = factory.newDocumentBuilder();
        }
        catch (ParserConfigurationException ignored)
        {
            // throw something here if you like.
        }
        assert builder != null;
        final Document doc = builder.parse(is);
        is.close();
        return doc;
    }