Class::newInstance() doesn't have any parameters (also, it's deprecated: better to use getConstructor() or getDeclaredConstructor() and call newInstance() on it).

Also, the generic agreement on your calls to makeAndPrint is failing.

This does what you wanted:

jshell> class Foo { }
| modified class Foo

jshell> class Bar extends Foo { }
| modified class Bar

jshell> class Baz extends Foo { }
| modified class Baz

jshell> class Main {
...> public static void main(String[] args) {
...> makeAndPrint(Foo.class);
...> makeAndPrint(Bar.class);
...> makeAndPrint(Baz.class);
...> }
...>
...> public static void makeAndPrint(Class<? extends Foo> klass) {
...> try {
...> Object o = klass.newInstance();
...> System.out.println("Created: " + o.toString());
...> } catch (Exception e) {
...> System.err.println("Failed: " + klass);
...> }
...> }
...> }
| created class Main

jshell> Main.main(new String[]{})
Created: REPL.$JShell$11$Foo@6a4f787b
Created: REPL.$JShell$12$Bar@7d9d1a19
Created: REPL.$JShell$13$Baz@39c0f4a

On Sat, 6 Feb 2021 at 20:56, Luís Oliveira <luismbo@gmail.com> wrote:

On Sat, 6 Feb 2021 at 16:29, Manfred Bergmann <manfred.bergmann@me.com> wrote:
> But this is kind of also possible in i.e. Java where you can say:
> Foo.class.newInstance() which uses reflection and is not normally used.
> But is effectively similar to make-instance `foo.

My Java is getting rustier and rustier, but maybe you can tell me why
the following program doesn't compile:

class Foo { }
class Bar extends Foo { }
class Baz extends Foo { }

class Main {
public static void main(String[] args) {
makeAndPrint(Foo.class);
makeAndPrint(Bar.class);
makeAndPrint(Baz.class);
}

public static void makeAndPrint(Class<Foo> klass) {
try {
Object o = klass.newInstance(klass);
System.out.println("Created: " + o.toString());
} catch (Exception e) {
System.err.println("Failed: " + klass);
}
}
}

The rough equivalent in Common Lisp would be:

(defclass foo () ())
(defclass bar (foo) ())
(defclass baz (foo) ())

(mapcar #'make-instance '(foo bar baz))

Luís