我的Java应用程序是否在OpenShift上运行

Question

I am just getting started with server applications and cloud services, and have signed up to OpenShift.

I have set everything up successfully using the Tomcat 7 cartridge, and pushed my first (very simple) code to the remote Git repository. It compiles and builds, but as far as I can see, when the application is restarted, doesn't run. I have checked all the logs, and there are no errors.

I have also tried going into the target folder of the repo and running java Main , but I get this error:

Exception in thread "main" java.lang.NoClassDefFoundError: Main (wrong name: helloworld/Main)

even though the Main.class file is right there.

The class is as follows:

public class Main
{

  public static void main(String[] args)
  {
      System.out.println("It works!");
  }   
}

I'm obviously missing something and I've searched most of the similar answers to no avail - can someone tell me what I'm doing wrong?

Answer 1

You can not run static main method (any java app entry point) in any application server environment (such as Tomcat, Jboss, Glassfish etc.). Application container search for class derived from the HttpServlet (for most of times), other words: your class have to inherit javax.servlet.http.HttpServlet .

As you can see in your exception: a java thread was already running, so the required first main method (application entry point) was started.