OnJava8-Examples/reflection/toys/ToyTest.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
*/