Proxying Objects Causes OutOfMemoryError

Question

I have retrieving my Object instances from a class with a method called getProxy. That method adds InvocationHandlers to extract out logic like tracing logic. Inside my TracingInvocationHandler, I print a statement before a method is executed and one after. I am able to run this fine through some functionality, but other methods cause an OutOfMemoryError. Those methods may create massive size lists within them...would this cause a problem? Is the Proxy to slow in performance to use it to do this?
     * @param obj param
     * @return returned
    public static Object getProxy(Object obj) {
        Object proxiedObject = obj;
        if(logger.isTraceEnabled()) {
            InvocationHandler tracingHandler = new TracingProxyHandler(proxiedObject);
            proxiedObject =
                Proxy.newProxyInstance(proxiedObject.getClass().getClassLoader(),
                    proxiedObject.getClass().getInterfaces(), tracingHandler);
        return proxiedObject;
public class TracingProxyHandler implements InvocationHandler {
    private static final Logger logger = Logger.getLogger(TracingProxyHandler.class);
    protected Object delegate;
     * Creates a new TracingProxyHandler object.
     * @param delegate param
    public TracingProxyHandler(Object delegate) {
        this.delegate = delegate;
     * @param proxy param
     * @param method param
     * @param args param
     * @return returned
     * @throws Throwable can be thrown
    public Object invoke(Object proxy, Method method, Object args[])
      throws Throwable {
        String methodName = "";
        String className = "";
        try {
            methodName = method.getName();
            className = method.getDeclaringClass().getName();
            enterScope(methodName, className);
            Object result = method.invoke(delegate, args);
            exitScope(methodName, className, result);
            return result;
        catch(InvocationTargetException e) {
            throw e.getTargetException();
        finally {}
     * @param methodName
     * @param className
    private void enterScope(String methodName, String className) {
        DateTime dateTime = new DateTime();
        logger.trace(dateTime.getDateTimeFormat1() + "\n   Entering -> " + className + "." +
            methodName);
     * @param methodName
     * @param className
     * @param result
     * @throws NoSuchMethodException
    private void exitScope(String methodName, String className, Object result) {
        Object resultOutput = result;
        DateTime dateTime = new DateTime();
        if(result instanceof List && (result != null)) {
            resultOutput = "Result is a collection != null and could possibly be too big to print.";
        logger.trace(dateTime.getDateTimeFormat1() + "\n    Exiting -> " + className + "." +
            methodName + "\n    Return  -> " + resultOutput);
}Thanks for your help,
-jay

Answer 1

Here is an example...this factory calls the ProxyFactory for every request for a ZipCodeBO interface.
     * This method retrieves the concrete implementation of the ProviderFacilityDAO.
     * @return ProviderFacilityDAO  the current implementation of the DAO.
    public static ProviderZipCodeBO getProviderZipCodeBO() {
        return (ProviderZipCodeBO)ProxyFactory.getProxy(new ProviderZipCodeBOImpl());
    }This is the actual code in the ZipCodeBOImpl
public class ProviderZipCodeBOImpl extends BaseBO implements ProviderZipCodeBO {
    public ProviderZipCodeBOImpl() {
        super();
     * @return returned
    public ZipCodeTO getAllZipCodeData() {
        ProviderZipCodeAssemblerDAO zipCodeDAO = this.getProviderZipCodeAssemblerDAO();
        ZipCodeTO zipCodeTO = zipCodeDAO.selectZipCodeTO();
        ProviderZipCodeTOList pfRegionZipCodes = zipCodeTO.getPfRegionZipCodes();
        ProviderZipCodeTOList regionZipCodes = null;
        ProviderZipCodeTO providerZipCodeTO = null;
        if(pfRegionZipCodes != null) {
            regionZipCodes = new ProviderZipCodeTOList();
            for(int i = 0; i < pfRegionZipCodes.size(); i++) {
                providerZipCodeTO = pfRegionZipCodes.get(i);
                if(StringHelper.isValid(providerZipCodeTO.getRegion())) {
                    regionZipCodes.add(providerZipCodeTO);
        zipCodeTO.setRegionZipCodes(regionZipCodes);
        zipCodeTO.setPfRegionZipCodes(regionZipCodes);
        return zipCodeTO;
     * @param zipCodeTO param
     * @param userId param
     * @return returned
    public DatabaseReportTOList saveZipCodeData(ZipCodeTO zipCodeTO, String userId) {
        //Set the user id into the composite object
        zipCodeTO.setUserId(userId);
        this.processTnexZipCodeRules(zipCodeTO);
        this.processRegionZipCodeRules(zipCodeTO);       
        ProviderZipCodeAssemblerDAO zipCodeDAO = this.getProviderZipCodeAssemblerDAO();
        //Run the load process
        return zipCodeDAO.insertZipCodeTO(zipCodeTO);
     * @param zipCodeTO
    public void processTnexZipCodeRules(ZipCodeTO zipCodeTO) {
        ProviderZipCodeEnumerationTO zipCodeList = null;
        ProviderZipCodeTO providerZipCodeTO = null;
        ProviderZipCodeTOList updatedList= null;
        //Business logic to set necessary values in tnex zip codes
        String serviceType = "PRIME";
        if(zipCodeTO != null && zipCodeTO.getTnexZipCodes() != null) {
            zipCodeList = zipCodeTO.getTnexZipCodes().elements();
            updatedList= new ProviderZipCodeTOList();           
            while(zipCodeList.hasMoreElements()) {
                providerZipCodeTO = zipCodeList.nextElement();
                //convert old dmis code to new CCS code
                if(providerZipCodeTO.getDmisCode().equalsIgnoreCase("NON-PSA")) {
                    providerZipCodeTO.setDmisCode("NP01");
                    providerZipCodeTO.setServiceType("NON-PRIME");
                else {
                    providerZipCodeTO.setServiceType(serviceType);
                if("Y".equalsIgnoreCase(providerZipCodeTO.getOptimizationIndicator())) //at least 1 Y
                    providerZipCodeTO.setAreaIndicator("Y");
                else if("N".equalsIgnoreCase(providerZipCodeTO.getOptimizationIndicator())) {
                    providerZipCodeTO.setAreaIndicator("N");
                else {
                    providerZipCodeTO.setAreaIndicator(null);
                updatedList.add(providerZipCodeTO);
            zipCodeTO.setTnexZipCodes(updatedList);
     * @param zipCodeTO
    public void processRegionZipCodeRules(ZipCodeTO zipCodeTO) {
        ProviderZipCodeEnumerationTO zipCodeList = null;
        ProviderZipCodeTO providerZipCodeTO = null;
        ProviderZipCodeTOList updatedList = null;
        if(zipCodeTO != null && zipCodeTO.getRegionZipCodes() != null) {
            zipCodeList = zipCodeTO.getRegionZipCodes().elements();
            updatedList= new ProviderZipCodeTOList();           
            while(zipCodeList.hasMoreElements()) {
                providerZipCodeTO = zipCodeList.nextElement();
                if(StringHelper.isValid(providerZipCodeTO.getRegion())) {
                    if(providerZipCodeTO.getRegion().equals("01") ||
                          providerZipCodeTO.getRegion().equals("02") ||
                          providerZipCodeTO.getRegion().equals("05") ||
                          providerZipCodeTO.getRegion().equals("17")) {
                        providerZipCodeTO.setRegion("17");
                    else if(providerZipCodeTO.getRegion().equalsIgnoreCase("PR") ||
                          providerZipCodeTO.getRegion().equals("03") ||
                          providerZipCodeTO.getRegion().equals("04") ||
                          providerZipCodeTO.getRegion().equals("06") ||
                          providerZipCodeTO.getRegion().equals("18")) {
                        providerZipCodeTO.setRegion("18");
                    else if(providerZipCodeTO.getRegion().equals("07") ||
                          providerZipCodeTO.getRegion().equals("08") ||
                          providerZipCodeTO.getRegion().equals("09") ||
                          providerZipCodeTO.getRegion().equals("10") ||
                          providerZipCodeTO.getRegion().equals("11") ||
                          providerZipCodeTO.getRegion().equalsIgnoreCase("AK") ||
                          providerZipCodeTO.getRegion().equals("12") ||
                          providerZipCodeTO.getRegion().equals("13") ||
                          providerZipCodeTO.getRegion().equals("14") ||
                          providerZipCodeTO.getRegion().equals("15") ||
                          providerZipCodeTO.getRegion().equals("19")) {
                        providerZipCodeTO.setRegion("19");
                    else {
                        throw new HNFSRuntimeException(
                            "Invalid region code loaded from IW database loading tables.");
                    updatedList.add(providerZipCodeTO);
            zipCodeTO.setRegionZipCodes(updatedList);
     * This method returns the implementation for ProviderZipCodeAssemblerDAO.
     * @return returned
    protected ProviderZipCodeAssemblerDAO getProviderZipCodeAssemblerDAO() {
        return ZipCodeDAOFactory.getProviderZipCodeAssemblerDAO();
}So for every layer Struts Action -> SLSB (SessionFacade) -> BO -> DAO, I would
retrieve my objects from this ProxyFactory so that I could proxy them and add
tracing and other things.