switch选择语句

public class aaaa {
    public static void main(String[] args) {
        switch (1) {
            case 0:
                System.out.println("123");
                break;
            case 1:
                System.out.println("456");
                break;
            case 2:
                System.out.println("789");
                break;
        }
    }
}