class JavaPerson{
    String name;
    public JavaPerson(String name) {
        this.name = name;
    }
    public void hello() {
        System.out.println("Hello: " + this.name);
    }
}

JavaPerson jerry = new JavaPerson("Jerry");
jerry.hello();

try {
jerry.hello2();
} catch(Exception e) {
    System.out.println("error: " + e.getMessage());
}