How to emulate C# as-operator in Java

Question

There are situations, where it is practical to have a type-cast return a null value instead of throwing a ClassCastException. C# has the as operator to do this. Is there something equivalent available in Java so you don't have to explicitly check for the ClassCastException?

Answer 1

Here's an implementation of as, as suggested by @Omar Kooheji:

public static <T> T as(Class<T> clazz, Object o){     if(clazz.isInstance(o)){         return clazz.cast(o);     }     return null; }  as(A.class, new Object()) --> null as(B.class, new B())  --> B 

Answer 2

I'd think you'd have to roll your own:

return (x instanceof Foo) ? (Foo) x : null; 

EDIT: If you don't want your client code to deal with nulls, then you can introduce a Null Object

interface Foo {     public void doBar(); } class NullFoo implements Foo {     public void doBar() {} // do nothing } class FooUtils {     public static Foo asFoo(Object o) {         return (o instanceof Foo) ? (Foo) o : new NullFoo();     } } class Client {     public void process() {         Object o = ...;         Foo foo = FooUtils.asFoo(o);         foo.doBar(); // don't need to check for null in client     } }