exceptionUsingHandle.java

private static void exceptionUsingHandle() {
   Integer age = -1;
   CompletableFuture<String> exceptionFuture = CompletableFuture.supplyAsync(() -> {
       if (age < 0) {
           throw new IllegalArgumentException("Age can not be negative");
       }
       if (age > 18) {
           return "Adult";
       } else {
           return "Child";
       }
   }).handle((result, ex) -> {
       if (ex != null) {
           System.out.println("Oops! We have an exception - " + ex.getMessage());
           return "Unknown!";
       }
       return result;
   });
   exceptionFuture.thenAccept(System.out::println); // Unknown!
}