为什么获取请求正在工作，但post不在java servlet中

我有一个servlet，我从get请求调用它，它工作正常，但是当我使用这个帖子请求调用它时

I have a servlet, I call it from a get request, it works, good, but when i call it using this post request

private static void doPostToMultiPart() throws URISyntaxException,
            ClientProtocolException, IOException {
        HttpClient client = HttpClientBuilder.create().build();
        HttpPost httpPost = new HttpPost(
                "http://localhost:8080/ServletExample1/multipart1");
        HttpResponse response = client.execute(httpPost);
        System.out.println("response code = "
                + response.getStatusLine().getStatusCode());
        String responseString = new BasicResponseHandler()
                .handleResponse(response);
        System.out.println(responseString);
    }

我在 handleResponse $上有例外c $ c>，这是：

Exception in thread "main" org.apache.http.client.HttpResponseException: Not Found
    at org.apache.http.impl.client.AbstractResponseHandler.handleResponse(AbstractResponseHandler.java:69)
    at org.apache.http.impl.client.BasicResponseHandler.handleResponse(BasicResponseHandler.java:65)
    at com.clients.PostClient1.doPostToMultiPart(PostClient1.java:28)
    at com.clients.PostClient1.main(PostClient1.java:16)

我打印的状态是 404

我有什么不对的请求？

注意

我可以给你servlet代码，它很简单，但我虽然因为我可以发出get请求，因此servlet工作正常，问题更可能来自我的post客户端请求。

Note

I could give you the servlet code, it is simple, but i though because i can make a get request, so the servlet is working fine and the problem is more likely from my post client request.

当我这样做时

httpPost.addHeader("Content-Type", "multipart/related;");

它有效，但当我这样做时：

it works, but when i do this:

httpPost.addHeader("Content-Type", MediaType.TEXT_HTML);

我再次得到了例外。如果客户端请求错误的内容类型，我想返回自定义消息。请帮助

i got the exception again. I want to return a custom message if the client requests a wrong content type. help please