java - Get parameterized type class of a generic variable -

public class foo {      public <t> void foo(final t t) {         final class<t> clazz = (class<t>) t.getclass();     }  }

i can not understand why t.getclass() return class<?> , not class<t> (or class<? extends t>) , why need make cast.

in way cast can fail ?

generics in java implemented using type erasure.

the type t not exist @ runtime , compiler substitutes t java.lang.object. following method compiled in bytecode:

public void foo(final object t)

UV code