如何使用java或curl实用工具将文档（图像等）附加到现有的工作项azuredevops。我试着用curl实用程序和java代码来实现它，但它不起作用。java代码示例：

try {
        // urlOfAttachment - url of attachment to devops azure, got with this method: 
        // https://stackoverflow.com/questions/62034062/upload-an-attachment-to-azure-devops-rest-api
        String jsonInputString = "[{\"op\":\"add\",\"path\":\"/relations/-\",\"value\":" +
                "{\"rel\":\"HelloFile.txt\",\"url\":\"" + urlOfAttachment + "\"," +
                "\"attributes\":{\"comment\":\"Spec for the work\"}}}]";

        URL url = new URL(
                "https://dev.azure.com/[organization]/[project]/_apis/wit" +
                        "/workItems/2?api-version=5.1");
        // PAT - token
        HttpURLConnection con = apiConnectionAttachToTicket(PAT, url, jsonInputString);

        try (BufferedReader br = new BufferedReader(
                new InputStreamReader(con.getInputStream(), "utf-8"))) {
            StringBuilder response = new StringBuilder();
            String responseLine = null;
            while ((responseLine = br.readLine()) != null) {
                response.append(responseLine.trim());
            }
            System.out.println("There would be response");
            System.out.println(response.toString());
            System.out.println("End of response");
        } catch (Exception ex) {
            System.out.println(ex.getMessage());
        }
        con.disconnect();
    } catch (MalformedURLException e) {
        e.printStackTrace();
    }

public static HttpURLConnection apiConnectionAttachToTicket(String PAT, URL url, String jsonInputString) {
    HttpURLConnection con = null;
    try {
        String AuthStr = ":" + PAT;
        Base64 base64 = new Base64();

        String encodedPAT = new String(base64.encode(AuthStr.getBytes()));
        con = (HttpURLConnection) url.openConnection();
        con.setRequestProperty("Authorization", "Basic " + encodedPAT);
        con.setRequestProperty("Content-Type", "application/json-patch+json");
        con.setDoOutput(true);
        System.out.println("URL - " + url.toString());
        System.out.println("PAT - " + encodedPAT);

        con.setDoInput(true);
        con.setRequestProperty("X-HTTP-Method-Override", "PATCH");
        con.setRequestMethod("POST");
        con.setRequestProperty("data", jsonInputString);
        System.out.println("Exit from function");
    } catch (Exception e) {
        System.out.println(e.getMessage());
    }
    return con;
}

此方法返回411错误。我认为是因为它没有将方法类型设置为patch，而是使用post。但是devopsazure不支持post（我在尝试使用curl时得到了它）。当我使用curl时，它返回消息：“您必须在请求主体中传递一个有效的文档”。但我检查了好几次，似乎是对的。curl请求示例：

curl -L -D- --user [mail]@gmail.com:[token] --header "Content-Type:application/json-patch+json" --request POST -d '{"op":"add","path":"/relations/-","value":"AttachedFile","url":"https://dev.azure.com/[orgranization]/280b4f85-e666-4069-8b3b-2116ff5d9b7a/_apis/wit/attachments/ff9f26e7-6595-462d-833c-40f9771f3035?fileName=HelloFile.txt","attributes":{"comment":"Spec for the work"}}}' https://dev.azure.com/[organization]/[project]/_apis/wit/workitems/2?api-version=6.0

有什么想法吗？