我是 jBPM 的新手。我正在使用 jBPM KIE 工作臺。正如您在第二張圖片中看到的，我在 KIE 外部數據對象部分添加了必要的導入。為什么我會收到錯誤？我需要對進口商品做其他事情嗎？我收到一個拋出的錯誤：[KBase: defaultKieBase]: Process Compilation error URL cannot be resolved to a typeURL cannot be resolved to a typeHttpURLConnection cannot be resolved to a typeHttpURLConnection cannot be resolved to a typeBufferedReader cannot be resolved to a typeBufferedReader cannot be resolved to a typeInputStreamReader cannot be resolved to a typeJava代碼：    try {        URL url = new URL("http://localhost:8080/users");        HttpURLConnection con = (HttpURLConnection) url.openConnection();        con.setRequestMethod("GET");        con.setRequestProperty("Content-Type", "application/json");        BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));        String inputLine;        StringBuffer content = new StringBuffer();        while ((inputLine = in.readLine()) != null) {            content.append(inputLine);        }        in.close();        System.out.println(content);    }    catch(Exception e){        throw new RuntimeException(e);    }