以下是你需要做的:

获取Apache HttpClient，这将使您能够发出所需的请求 用它创建一个HttpPost请求，并添加头应用程序/x-www-form-urlencoded 创建一个StringEntity，并将JSON传递给它 执行调用

代码大致如下(你仍然需要调试它并使它工作):

// @Deprecated HttpClient httpClient = new DefaultHttpClient();
HttpClient httpClient = HttpClientBuilder.create().build();
try {
    HttpPost request = new HttpPost("http://yoururl");
    StringEntity params = new StringEntity("details={\"name\":\"xyz\",\"age\":\"20\"} ");
    request.addHeader("content-type", "application/x-www-form-urlencoded");
    request.setEntity(params);
    HttpResponse response = httpClient.execute(request);
} catch (Exception ex) {
} finally {
    // @Deprecated httpClient.getConnectionManager().shutdown(); 
}

protected void sendJson(final String play, final String prop) {
     Thread t = new Thread() {
     public void run() {
        Looper.prepare(); //For Preparing Message Pool for the childThread
        HttpClient client = new DefaultHttpClient();
        HttpConnectionParams.setConnectionTimeout(client.getParams(), 1000); //Timeout Limit
        HttpResponse response;
        JSONObject json = new JSONObject();

            try {
                HttpPost post = new HttpPost("http://192.168.0.44:80");
                json.put("play", play);
                json.put("Properties", prop);
                StringEntity se = new StringEntity(json.toString());
                se.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
                post.setEntity(se);
                response = client.execute(post);

                /*Checking response */
                if (response != null) {
                    InputStream in = response.getEntity().getContent(); //Get the data in the entity
                }

            } catch (Exception e) {
                e.printStackTrace();
                showMessage("Error", "Cannot Estabilish Connection");
            }

            Looper.loop(); //Loop in the message queue
        }
    };
    t.start();
}

我发现这个问题寻找如何从java客户端发送post请求到谷歌端点的解决方案。以上答案，很可能是正确的，但在谷歌端点的情况下不工作。

谷歌端点的解决方案。

Request body must contains only JSON string, not name=value pair. Content type header must be set to "application/json". post("http://localhost:8888/_ah/api/langapi/v1/createLanguage", "{\"language\":\"russian\", \"description\":\"dsfsdfsdfsdfsd\"}"); public static void post(String url, String json ) throws Exception{ String charset = "UTF-8"; URLConnection connection = new URL(url).openConnection(); connection.setDoOutput(true); // Triggers POST. connection.setRequestProperty("Accept-Charset", charset); connection.setRequestProperty("Content-Type", "application/json;charset=" + charset); try (OutputStream output = connection.getOutputStream()) { output.write(json.getBytes(charset)); } InputStream response = connection.getInputStream(); } It sure can be done using HttpClient as well.

Java 11标准的HTTP客户端API，实现了HTTP/2和Web Socket，可以在java.net.HTTP找到。*:

String payload = "{\"name\": \"myname\", \"age\": \"20\"}";
HttpClient client = HttpClient.newHttpClient();

HttpRequest request = HttpRequest.newBuilder(URI.create("www.site.com"))
            .header("content-type", "application/json")
            .POST(HttpRequest.BodyPublishers.ofString(payload))
            .build();
    
HttpResponse<String> response = client.send(request, BodyHandlers.ofString());

Java 8与apache httpClient 4

CloseableHttpClient client = HttpClientBuilder.create().build();
HttpPost httpPost = new HttpPost("www.site.com");


String json = "details={\"name\":\"myname\",\"age\":\"20\"} ";

        try {
            StringEntity entity = new StringEntity(json);
            httpPost.setEntity(entity);

            // set your POST request headers to accept json contents
            httpPost.setHeader("Accept", "application/json");
            httpPost.setHeader("Content-type", "application/json");

            try {
                // your closeablehttp response
                CloseableHttpResponse response = client.execute(httpPost);

                // print your status code from the response
                System.out.println(response.getStatusLine().getStatusCode());

                // take the response body as a json formatted string 
                String responseJSON = EntityUtils.toString(response.getEntity());

                // convert/parse the json formatted string to a json object
                JSONObject jobj = new JSONObject(responseJSON);

                //print your response body that formatted into json
                System.out.println(jobj);

            } catch (IOException e) {
                e.printStackTrace();
            } catch (JSONException e) {

                e.printStackTrace();
            }

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }

使用HttpURLConnection可能是最简单的。

http://www.xyzws.com/Javafaq/how-to-use-httpurlconnection-post-data-to-web-server/139

你将使用JSONObject或其他东西来构造JSON，但不是用来处理网络;你需要序列化它，然后将它传递给一个HttpURLConnection到POST。