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Improve your REST Webservice response time using java.util.TimerTask

A while ago, I built an MAF application, which was consuming a few REST webservices from Oracle Java Cloud. But for each request from the app, the response JSON was getting created, and which made the app response very slow. 
So, I created the contents of the REST response as a scheduled job. My data wasn't getting changed that often, so I choose to build my REST responses every morning at 10am using java.util.TimerTask.

Used Software: JDeveloper 12.1.3

#1. REST response POJOs :
public class Feed {
    public String url;
    public String source;
    public Feed() {
    public Feed(String source, String url) {
    public void setSource(String source) {
        this.source = source;

    public String getSource() {
        return source;

    public void setUrl(String url) {
        this.url = url;

    public String getUrl() {
        return url;


@XmlRootElement(name = "feeds")
public class FeedsArray {

    private List<Feed> feeds;

    public void setFeeds(List<Feed> feeds) {
        this.feeds = feeds;

    public List<Feed> getFeeds() {
        return feeds;

#2. TimerTask class :
You need to create a class which extends java.util.TimerTask and override run() to put your custom code.
I have used a Singleton object (Feeds) to create and store my response.

public class FeedRSSScheduler extends TimerTask {
    public FeedRSSScheduler() {

    public void run() {


public class Feeds {
    private static Feeds instance = null;
    private FeedsArray feedsArray;
    protected Feeds() {
    public static Feeds getInstance() {
      if(instance == null) {
         instance = new Feeds();
      return instance;

    public FeedsArray getFeedsArray() {
        if(feedsArray == null) {
        return feedsArray;
    public void buildFeedsMap() {
        // PUT your custom code here to populate the FeedsArray object


#3. Servlet container class :
public class JobSchedulerServlet extends ServletContainer {
    private final static long ONCE_PER_DAY = 1000*60*60*24;
    private final static int TEN_AM = 10;
    private final static int ZERO_MINUTES = 0;
    public JobSchedulerServlet(Application application) {

    public void init() throws ServletException {   

    public JobSchedulerServlet(Class<? extends Application> class1) {

    public JobSchedulerServlet() {
    private Date getTomorrowMorning10AM(){
        Date date2am = new Date();
        return date2am;
    private void startFeedRSSTask(){
        FeedRSSScheduler feedRSSScheduler = new FeedRSSScheduler();
        Timer timer = new Timer(); 
        timer.schedule(feedRSSScheduler, getTomorrowMorning10AM(), ONCE_PER_DAY);

#4. Register your Servlet container class in web.xml :

#5. Create REST service :

public class FeedMap {
    public FeedsArray getFeedsMap() {
        return Feeds.getInstance().getFeedsArray();

/// URL to access this service : http://<server>:<port>/<context_root>/feeds/sources

That's it. When you create and deploy this WAR file, the job will start instantly and then every day morning at 10am.


  1. TimerTask is old approach, use ScheduledThreadPoolExecutor


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