问将react与redux一起使用时的net::ERR_CONNECTION_REFUSED

EN

import Axios from 'axios';
import { PRODUCT_LIST_FAIL, PRODUCT_LIST_REQUEST, PRODUCT_LIST_SUCCESS } from '../constraints/productConstraints';

const listProducts = () => async (dispatch) => {
try {
    dispatch({ type: PRODUCT_LIST_REQUEST });
    const { data } = await Axios.get('http://localhost:3001/product');
    dispatch({ type: PRODUCT_LIST_SUCCESS, payload: data });
}
catch(error) {
    dispatch({ type: PRODUCT_LIST_FAIL, payload: error.message });
 }
}

export { listProducts }

const Home = () => {
const productList = useSelector(state => state.productList);
const { products, loading, error } = productList;
const dispatch = useDispatch();
useEffect(() => {
    dispatch(listProducts());
    return () => {

    }
},[]);
}