Re: ServiceLoader.load(Class, ClassLoader) bug

[Peter Levart]

I reported this as Bug ID: 7198496

Regards, Peter

On 09/13/2012 05:13 PM, Peter Levart wrote:

Hi,

The javadoc for java.util.ServiceLoader.load(Class service, ClassLoader loader) method says about it's parameters:

     * @param  service
     *         The interface or abstract class representing the service
     *
     * @param  loader

* The class loader to be used to load provider-configuration files

     *         and provider classes, or <tt>null</tt> if the system class

* loader (or, failing that, the bootstrap class loader) is to be

     *         used

So one might think that calling:

    ServiceLoader.load(service, null);

is equivalent to:

    ServiceLoader.load(service, ClassLoader.getSystemClassLoader());

But it is not. Either this is a bug in ServiceLoader or javadoc has to be changed.

If null is specified as ClassLoader then ServiceLoader locates META-INF/services/interface.name resources using system ClassLoader (using ClassLoader.getSystemResources), but loads implementation classes using bootstrap ClassLoader (using Class.forName(className, true, null)).

If this is not the expected behaviour then the fix is simple (in the private constructor of ServiceLoader[217]):

-    loader = cl;
+   loader = cl == null ? ClassLoader.getSystemClassLoader() : cl;



Regards, Peter