I have upgraded tomcat from version 7.0.34 to version 8.0.33, and since then I have been facing a problem to share the web application context and Junit context.
I have a web application with singleton class that gathers statistic data about the web application. I also have Junit that runs the web application in embedded tomcat. the Junit queries the web application and then checks the statistic data.
I try to make a simple example:
the singleton:
public class Counter {
private static Counter instance;
private AtomicLong counter;
private Counter(){}
public static Counter getInstance(){
if(instance == null){
synchronized (Counter.class) {
if(instance == null){
instance = new Counter();
}
}
}
return instance;
}
public long incrementAndGet(){
return counter.incrementAndGet();
}
public long getValue(){
return counter.get();
}
}
the servlet:
@WebServlet(name="servlet",loadOnStartup=1, urlPatterns="/servletTest")
public class Servlet extends HttpServlet{
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.getWriter().write("Hi, you are the #" + Counter.getInstance().incrementAndGet() + " visitor");
}
}
contextListener:
public class MyContextListener implements ServletContextListener{
@Override
public void contextDestroyed(ServletContextEvent arg0) {}
@Override
public void contextInitialized(ServletContextEvent arg0) {
Counter.getInstance().incrementAndGet();
}
}
Test unit:
public void mainTest() throws ServletException, LifecycleException{
Tomcat tomcat = new Tomcat();
tomcat.setPort(50000);
StandardContext ctx = (StandardContext) tomcat.addWebapp("/fe", System.getProperty("FEBaseDir")); //The FEBaseDir property is supposed to be taken from Maven build using 'test' profile
tomcat.start();
Counter.getInstance().getValue();
}
when I used Tomcat 7, everything worked fine. but since I upgraded tomcat to tomcat 8.0.33, It hasn't been working. the singleton class with the static data loads twice. first by the tomcat and then by the Junit itself.
I have tried to pass tomcat a classloader but it doesn't work.
public void mainTest() throws ServletException, LifecycleException{
Tomcat tomcat = new Tomcat();
tomcat.setPort(50000);
StandardContext ctx = (StandardContext) tomcat.addWebapp("/fe", System.getProperty("FEBaseDir")); //The FEBaseDir property is supposed to be taken from Maven build using 'test' profile
ctx.setCrossContext(true);
ctx.setLoader((Loader) new WebappLoader(Thread.currentThread().getContextClassLoader()));
ctx.setParentClassLoader(Thread.currentThread().getContextClassLoader());
tomcat.getEngine().setParentClassLoader(Thread.currentThread().getContextClassLoader());
tomcat.getHost().setParentClassLoader(Thread.currentThread().getContextClassLoader());
tomcat.getService().setParentClassLoader(Thread.currentThread().getContextClassLoader());
tomcat.getServer().setParentClassLoader(Thread.currentThread().getContextClassLoader());
tomcat.start();
Counter.getInstance().getValue();
}
What am I doing wrong?
