79 lines
2.2 KiB
Java
79 lines
2.2 KiB
Java
// reflection/toys/ToyTest.java
|
|
// (c)2021 MindView LLC: see Copyright.txt
|
|
// We make no guarantees that this code is fit for any purpose.
|
|
// Visit http://OnJava8.com for more book information.
|
|
// Testing class Class
|
|
// {java reflection.toys.ToyTest}
|
|
package reflection.toys;
|
|
import java.lang.reflect.InvocationTargetException;
|
|
|
|
interface HasBatteries {}
|
|
interface Waterproof {}
|
|
interface Shoots {}
|
|
|
|
class Toy {
|
|
// Comment out the following zero-argument
|
|
// constructor to see NoSuchMethodError
|
|
public Toy() {}
|
|
public Toy(int i) {}
|
|
}
|
|
|
|
class FancyToy extends Toy
|
|
implements HasBatteries, Waterproof, Shoots {
|
|
public FancyToy() { super(1); }
|
|
}
|
|
|
|
public class ToyTest {
|
|
static void printInfo(Class cc) {
|
|
System.out.println("Class name: " + cc.getName() +
|
|
" is interface? [" + cc.isInterface() + "]");
|
|
System.out.println(
|
|
"Simple name: " + cc.getSimpleName());
|
|
System.out.println(
|
|
"Canonical name : " + cc.getCanonicalName());
|
|
}
|
|
@SuppressWarnings("deprecation")
|
|
public static void main(String[] args) {
|
|
Class c = null;
|
|
try {
|
|
c = Class.forName("reflection.toys.FancyToy");
|
|
} catch(ClassNotFoundException e) {
|
|
System.out.println("Can't find FancyToy");
|
|
System.exit(1);
|
|
}
|
|
printInfo(c);
|
|
for(Class face : c.getInterfaces())
|
|
printInfo(face);
|
|
Class up = c.getSuperclass();
|
|
Object obj = null;
|
|
try {
|
|
// Requires public zero-argument constructor:
|
|
obj = up.newInstance();
|
|
} catch(Exception e) {
|
|
throw new
|
|
RuntimeException("Cannot instantiate");
|
|
}
|
|
printInfo(obj.getClass());
|
|
}
|
|
}
|
|
/* Output:
|
|
Class name: reflection.toys.FancyToy is interface?
|
|
[false]
|
|
Simple name: FancyToy
|
|
Canonical name : reflection.toys.FancyToy
|
|
Class name: reflection.toys.HasBatteries is interface?
|
|
[true]
|
|
Simple name: HasBatteries
|
|
Canonical name : reflection.toys.HasBatteries
|
|
Class name: reflection.toys.Waterproof is interface?
|
|
[true]
|
|
Simple name: Waterproof
|
|
Canonical name : reflection.toys.Waterproof
|
|
Class name: reflection.toys.Shoots is interface? [true]
|
|
Simple name: Shoots
|
|
Canonical name : reflection.toys.Shoots
|
|
Class name: reflection.toys.Toy is interface? [false]
|
|
Simple name: Toy
|
|
Canonical name : reflection.toys.Toy
|
|
*/
|