Interface is not visible from ClassLoader when using a proxy?

Question

I am seeing following exception when I try to use dynamic proxy

 com.intellij.rt.execution.application.AppMain DynamicProxy.DynamicProxy
Exception in thread         


        

Answer 1

If this is web application, then you should use the web application classloader when creating dynamic proxy. So, for example instead of:

Proxy.newProxyInstance(
  ClassLoader.getSystemClassLoader(),
  new Class < ? >[] {MyInterface.class},
  new InvocationHandler() {
    // (...)
});

try:

Proxy.newProxyInstance(
  this.getClass().getClassLoader(), // here is the trick
  new Class < ? >[] {MyInterface.class},
  new InvocationHandler() {
    // (...)
});

For instance, hierarchy of tomcat class loaders (other web containers have similar) is following:

      Bootstrap
          |
       System
          |
       Common
       /     \
  Webapp1   Webapp2 ... 

And it is the webapp classloader which contains classes and resources in the /WEB-INF/classes directory of your web application, plus classes and resources in JAR files under the /WEB-INF/lib directory of your web application.