Q:

Error when deploying web app on Glassfish

I'm using Eclipse + Glassfish 4.0
When I deploying a simple project, following error appears :
cannot Deploy Testmart 

deploy is failing=Error occurred during deployment: Exception while loading 
the app : java.lang.IllegalStateException: ContainerBase.addChild: start: 
org.apache.catalina.LifecycleException: java.lang.RuntimeException: 
Servlet web service endpoint '' failure. Please see server.log for more details.

EDIT :
ProductCatalog.java Class :
import org.hamed.train.service.ProductServiceImp;

@WebService
public class ProductCatalog {
    ProductServiceImp productService = new ProductServiceImp();
    @WebMethod
    public List<String> getProducts() {
        return productService.getProductCategories();
    }
    public List<String> getProducts(String category) {
        return productService.getProducts(category);
    }
}

system.log content :
http://txs.io/B7P

A:

According to @Silly Freak's comment, I found the answer.
These two method should not have the same name :
ProductCatalog.java
public List<String> getProducts() {
        return productService.getProductCategories();
    }

public List<String> getProducts(String category) {
        return productService.getProducts(category);
    }

Solution:
I changed first method name to something else and worked like a charm.

