Stop when one future task has completed in java

Question

I have 2 FutureTask Objects. My tasks are running parallelly. However, What I want is that as soon as one of the FutureTask method completes its execution/job the other should stop. But inside method(method1() /method2()) how can I stop that?

public class Main {
    public static void main(String[] args) {
        try {
            ExecutorService executor = Executors.newSingleThreadExecutor();
            
            //task 1
            Future future1 = executor.submit(new Callable() {
                @Override
                public Response call() throws Exception {
                    return method1();
                }
            });
            //task 2
            Future future2 = executor.submit(new Callable() {
                @Override
                public Response call() throws Exception {
                    return method2();
                }
            });
            Response response1 = (Response) future1.get();
            Response response2 = (Response)future2.get();
            executor.shutdown();
            if(response1!=null || response2.getMsg()!=null){
                System.out.println(response2.getMsg());
            }else{
                System.out.println("error");

            }
        }catch (Exception ex){
            ex.printStackTrace();
        }
    }

    //first method
    private static Response method1() {
        Response response=new Response();
        response.setMsg("test1"); //  ==> this might take long time
        return response;
    }
    //second method
    private static Response method2() {
        Response response=new Response();
        response.setMsg("test1"); //  ==> this might take long time
        return response;
    }

}

class Response {
    String msg;

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }
}

Can anyone help me to understand this?