Win a copy of The Little Book of Impediments (e-book only) this week in the Agile and Other Processes forum!
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

primitive types not castable as lang.Object

 
Pho Tek
Ranch Hand
Posts: 782
Chrome Python Ubuntu
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
This statement is dead on obvious but my problem is:
I need to call this method:
someMethod (java.lang.Class type, java.lang.Object value)

Scenario 1: (Works)
boolean bP = true
Boolean bW = new Boolean(bP);
someMethod( Boolean.class, bW ); //ok
Scenario 2: (Compile error)
someMethod( boolean.class, bP ); //error
Is there any way to coerce scenario #2 to work?
Pho
 
Grant Crofton
Ranch Hand
Posts: 154
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
No, if the method wants an Object, the method'll have an Object.
You could shorten it slightly with someMethod( Boolean.class, new Boolean( bP ) );
What's wrong with doing it the first way?
 
Anonymous
Ranch Hand
Posts: 18944
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Solution one is the way you coerce it to work. The problem you are describing is the reason for the existence of the wrapper classes that provide object representations of primitive types.
 
Pho Tek
Ranch Hand
Posts: 782
Chrome Python Ubuntu
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Well if you think about it,
boolean.class is a subclass of "Class".
and "Class" is a subclass of "Object".
So does it mean that the relationships are not transitive ?
Pho
 
Randall Twede
Ranch Hand
Posts: 4489
3
Java Python Scala
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
there is no Class called boolean only one called Boolean
 
Cindy Glass
"The Hood"
Sheriff
Posts: 8521
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
That's why they are called "primitives". Because they are NOT objects. when you wrapped the boolean primitive with a Boolean object wrapper it worked.
 
Tony Alicea
Desperado
Sheriff
Posts: 3226
5
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I know this is of no importance here but... In C#, primitives can be treated as objects transparently.
 
Cindy Glass
"The Hood"
Sheriff
Posts: 8521
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Tony. . . naughty, naughty - reading up on microsoft stuff when no one is looking .
So are they really primitives and the language disguises that (I think not) or did they make everything a true object??? It is really just the primitives, the special handling of strings, and arrays that prevent java from being a pure object oriented language. How many concessions did C# make???
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic