Modify your constructor to the following so that it calls the base class constructor properly:
public class MyExceptionClass : Exception
{
public MyExceptionClass(string message, string extrainfo) : base(message)
{
//other stuff here
}
}
Note that a constructor is not something that you can call anytime within a method. That's the reason you're getting errors in your call in the constructor body.
Update:
Some 10 years later perhaps the best way to test a private method, or any inaccessible member, is via @Jailbreak
from the Manifold framework.
@Jailbreak Foo foo = new Foo();
// Direct, *type-safe* access to *all* foo's members
foo.privateMethod(x, y, z);
foo.privateField = value;
This way your code remains type-safe and readable. No design compromises, no overexposing methods and fields for the sake of tests.
If you have somewhat of a legacy Java application, and you're not allowed to change the visibility of your methods, the best way to test private methods is to use reflection.
Internally we're using helpers to get/set private
and private static
variables as well as invoke private
and private static
methods. The following patterns will let you do pretty much anything related to the private methods and fields. Of course, you can't change private static final
variables through reflection.
Method method = TargetClass.getDeclaredMethod(methodName, argClasses);
method.setAccessible(true);
return method.invoke(targetObject, argObjects);
And for fields:
Field field = TargetClass.getDeclaredField(fieldName);
field.setAccessible(true);
field.set(object, value);
Notes:
1. TargetClass.getDeclaredMethod(methodName, argClasses)
lets you look into private
methods. The same thing applies for
getDeclaredField
.
2. The setAccessible(true)
is required to play around with privates.
Best Answer
Yes, an abstract class can have a constructor. Consider this:
The superclass
Product
is abstract and has a constructor. The concrete classTimesTwo
has a constructor that just hardcodes the value 2. The concrete classTimesWhat
has a constructor that allows the caller to specify the value.Abstract constructors will frequently be used to enforce class constraints or invariants such as the minimum fields required to setup the class.