How can I improve JAXB performance? - jaxb

Question

Here is my conversion code. This is taking long time when we are dealing with large data... Calling the method almost a million times... We could clearly see that it is holding threads for a while.
Please suggest me some ways to improve the performance!
public class GenericObjectXMLConverter<T> {
private T t = null;
private static JAXBContext jaxbContext =null;
public GenericObjectXMLConverter() {
}
public GenericObjectXMLConverter(T obj){
t = obj;
}
protected final Logger log = Logger.getLogger(getClass());
/**
* Converts the java Object and into a xml string message type.
* #param object the object to convert
* #return String the converted xml message as string
*/
public String objectToXMLMessage(T object) {
StringWriter stringWriter = new StringWriter();
//JAXBContext jaxbContext=null;
try {
jaxbContext = JAXBContext.newInstance(object.getClass());
Marshaller jaxbMarshaller = jaxbContext.createMarshaller();
jaxbMarshaller.marshal(object, stringWriter);
} catch (JAXBException e) {
log.warn("JAXBException occured while converting the java object into xml string :"+e.getMessage());
}
/*if(log.isDebugEnabled())
log.debug("xml string after conversion:"+stringWriter.toString());*/
return stringWriter.toString();
}
/**
* Converts a xml string message into a Java Object
* #param string the string message to convert
* #return Object the result as Java Object. If the message parameter is null then
* this method will simply return null.
*/
#SuppressWarnings("unchecked")
public T xmlToObject(String message) {
if(message.equals("") || message.equals(" ") || message.length()==0){
return null;
}else{
T object=null;
try {
jaxbContext = JAXBContext.newInstance(t.getClass());
StringReader reader = new StringReader(message);
Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
object = (T)jaxbUnmarshaller.unmarshal(reader);
} catch (JAXBException e) {
log.warn("JAXBException occured while converting the xml string into a Java Object :"+e.getMessage());
}
/* if(log.isDebugEnabled()){
log.debug("Java object after conversion:"+object.toString());
}*/
return object;
}
}
}

Answer 1

Performance and JAXB Runtime Classes
You should avoid creating the same JAXBContext over and over. JAXBContext is thread safe and should be reused to improve performance.
Marshaller/Unmarshaller are not thread safe, but are quick to create. It's not as big a deal to reuse them.

Answer 2

You should create single JAXBContext object per your bean class.
Here is my version to maintain singleton object of JAXBContext per bean class.
public class MyJAXBUtil {
public static final Map<String, JAXBContext> JAXB_MAP = new HashMap<>();
public static JAXBContext getJAXBContext(Object object) {
if(JAXB_MAP.get(object.getClass().getCanonicalName()) != null) {
return JAXB_MAP.get(object.getClass().getCanonicalName());
}else {
try {
JAXBContext jaxbContext = JAXBContext.newInstance(object.getClass());
JAXB_MAP.put(object.getClass().getCanonicalName(), jaxbContext);
return jaxbContext;
} catch (JAXBException e) {
e.printStackTrace();
return null;
}
}
}
}
You can call getJAXBContext method when you need JAXBContext of your bean class and create Marshaller/Unmarshaller locally.