Primitives and wrappers

Question

int i=10;
Integer I=50;
System.out.println(Integer.class.isInstance(i)); // prints true
System.out.println(int.class.isInstance(I)); // prints false
System.out.println(Integer.class.isAssignableFrom(int.class)); // prints false
System.out.println(int.class.isAssignableFrom(Integer.class)); // prints falseThe problem:
I have two classes (not objects) at runtime. One is supposed to be for a primitive (ex. int.class) and the other is for its wrapper (Integer.class). I need to validate that both classes ara compatible (assignable to each other). The only statement above that returns true I cannot use because it accepts an object as a parameter which I don't have.
Thank you

Answer 1

If there were int.class, this example would compile and work:
C:\doku>java testVersion
false
true
false
true
false
false
public class testVersion
  public static void main( String args[] ) throws Exception
    System.out.println( okay( int.class, Short.class ) );
    System.out.println( okay( int.class, Integer.class ) );
    System.out.println( okay( int.class, Long.class ) );
    System.out.println( okay( short.class, Short.class ) );
    System.out.println( okay( short.class, Integer.class ) );
    System.out.println( okay( short.class, Long.class ) );
  static boolean okay( Class pri, Class obj )
    java.lang.reflect.Constructor[]     ct = obj.getConstructors();
    for ( int i = 0; i < ct.length; i++ )
      Class[]   params = ct[ i ].getParameterTypes();
      if ( 1 == params.length && params[ 0 ] == pri )
        return true;
    return false;
}