用jarslink做module隔离时,dubbo调用会抛ClassNotFoundException.经查是ClassLoader不一致.

```
    public static Class<?> getReturnType(Invocation invocation) {
        try {
            if (invocation != null && invocation.getInvoker() != null
                    && invocation.getInvoker().getUrl() != null
                    && !invocation.getMethodName().startsWith("$")) {
                String service = invocation.getInvoker().getUrl().getServiceInterface();
                if (service != null && service.length() > 0) {
                    Class<?> cls = ReflectUtils.forName(service);
                    Method method = cls.getMethod(invocation.getMethodName(), invocation.getParameterTypes());
                    if (method.getReturnType() == void.class) {
                        return null;
                    }
                    return method.getReturnType();
                }
            }
        } catch (Throwable t) {
            logger.warn(t.getMessage(), t);
        }
        return null;
    }
```
return true;
                }
            }
        }
        return false;
    }
    public static Object getEmptyObject(Class<?> returnType) {
        return getEmptyObject(returnType, new HashMap<Class<?>, Object>(), 0);
    }
    private static Object getEmptyObject(Class<?> returnType, Map<Class<?>, Object> emptyInstances, int level) {
        if (level > 2)
            return null;
        if (returnType == null) {
            return null;
        } else if (returnType == boolean.class || returnType == Boolean.class) {
            return false;
        } else if (returnType == char.class || returnType == Character.class) {
            return '\0';
        } else if (returnType == byte.class || returnType == Byte.class) {
            return (byte) 0;
        } else if (returnType == short.class || returnType == Short.class) {
            return (short) 0;
        } else if (returnType == int.class || returnType == Integer.class) {
            return 0;
        } else if (returnType == long.class || returnType == Long.class) {
            return 0L;
        } else if (returnType == float.class || returnType == Float.class) {
            return 0F;
        } else if (returnType == double.class || returnType == Double.class) {
            return 0D;