collection class polymorphism

[siddharth das]

hi all,
i have a doubt.
why

List<Animal> li=new ArrayList<Animal>();

gives compilation error.Animal is a user defined class.
and

ArrayList<Object> ob=new ArrayList<Object>();

gives comilation error?
please suggest me.Thank You.

[Jaikiran Pai]

Moving to JiG(B).

[Jesper de Jong]

It should not give a compilation error, unless for example class Animal can't be found. If that's the case, then make sure it is on the classpath.

What exactly is the compilation error you get?

[camilo lopes]

none of them compels with error, however the code below compels with error sees:

List<Object> list = new ArrayList<String>();

the polimorfismo does not function with generics types as it functions with arrays.

[Red Smith]

Make sure you are using the Java 5 or Java 6.