While trying to load jar file at run time we are getting
following exception:
java.lang.IllegalArgumentException: object is not an instance of declaring
class at
jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(java.base@9-ea/Native
Method) at
jdk.internal.reflect.NativeMethodAccessorImpl.invoke(java.base@9-ea/NativeMeth
odAccessorImpl.java:62) at
jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(java.base@9-ea/Delega
tingMethodAccessorImpl.java:43) at
 java.lang.reflect.Method.invoke(java.base@9-ea/Method.java:533)
The exception is seen only with JDK9, code was working fine with the previous
versions of JDKs i.e. JDK 8, JDK 7, JDK 6, etc.
Please note, Code does not throw any compile time error when compiled with
JDK 9, but it fails at runtime with above exception.
***********************
JDK Version:
java version "9-ea"
Java(TM) SE Runtime Environment (build 9-ea+123)
Java HotSpot(TM) 64-Bit Server VM (build 9-ea+123, mixed mode)

Attached a test program, it tries to load a given jar file to
system class loader at run time.
Code throws exception (IllegalArgumentException) when running it against
JDK 9 but works fine with earlier versions of JDKs(i.e. 8/7/6).
Compile attached program and invoke it as:
java LoadMyJar "my.pack.MyPackage" c:\mypack.jar
First argument it takes is a class name which should be the part of jar file
and second argument is the jar file itself.
Note: You could use any jar file though I have attached a sample mypack.jar
with the bug.