Input validation while using streams-CodePudding

I figured out how to use streams-lambdas instead of for loop (just started with streams and lambdas)

this is the previous method i had

public void findVehicle(){
        System.out.println("Input a vehicle rego: ");
        in = new Scanner(System.in);
        String rego = in.nextLine();

        for (int i=0; i<vehicles.size();i  ){
            if (vehicles.get(i).getRego().equals(rego)){
                System.out.println(vehicles.get(i).toString());
                return;
            }
        }
        System.out.println("The vehicle does not exist.");
    }

and this is my method now

public void findVehicle(){
        System.out.println("Input a vehicle rego: ");
        in = new Scanner(System.in);
        String rego = in.nextLine();


           vehicles.stream()
                    .filter(vehicle -> vehicle.getRego().equals(rego.toUpperCase()))
                    .forEach(System.out::println);
}

this stream works perfectly but i want it to return once found and printed the vehicle and if vehicle not found the method continues and prints the error statement. Thanks!

CodePudding user response：

Try this.

vehicles.stream()
    .filter(v -> v.getRego().equals(rego.toUpperCase()))
    .findFirst()
    .ifPresentOrElse(
        System.out::println,
        () -> System.out.println("The vehicle does not exist."));