Java - sending HTTP parameters via POST method easily

Here is a simple example that submits a form then dumps the result page to System.out. Change the URL and the POST params as appropriate, of course:

import java.io.*; import java.net.*; import java.util.*; class Test { public static void main(String[] args) throws Exception { URL url = new URL("http://example.net/new-message.php"); Map<String,Object> params = new LinkedHashMap<>(); params.put("name", "Freddie the Fish"); params.put("email", "[email protected]"); params.put("reply_to_thread", 10394); params.put("message", "Shark attacks in Botany Bay have gotten out of control. We need more defensive dolphins to protect the schools here, but Mayor Porpoise is too busy stuffing his snout with lobsters. He's so shellfish."); StringBuilder postData = new StringBuilder(); for (Map.Entry<String,Object> param : params.entrySet()) { if (postData.length() != 0) postData.append('&'); postData.append(URLEncoder.encode(param.getKey(), "UTF-8")); postData.append('='); postData.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8")); } byte[] postDataBytes = postData.toString().getBytes("UTF-8"); HttpURLConnection conn = (HttpURLConnection)url.openConnection(); conn.setRequestMethod("POST"); conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); conn.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length)); conn.setDoOutput(true); conn.getOutputStream().write(postDataBytes); Reader in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8")); for (int c; (c = in.read()) >= 0;) System.out.print((char)c); } } 

If you want the result as a String instead of directly printed out do:

 StringBuilder sb = new StringBuilder(); for (int c; (c = in.read()) >= 0;) sb.append((char)c); String response = sb.toString(); 

I couldn't get Alan's example to actually do the post, so I ended up with this:

String urlParameters = "param1=a&param2=b&param3=c"; URL url = new URL("http://example.com/index.php"); URLConnection conn = url.openConnection(); conn.setDoOutput(true); OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream()); writer.write(urlParameters); writer.flush(); String line; BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream())); while ((line = reader.readLine()) != null) { System.out.println(line); } writer.close(); reader.close(); 

I find HttpURLConnection really cumbersome to use. And you have to write a lot of boilerplate, error prone code. I needed a lightweight wrapper for my Android projects and came out with a library which you can use as well: DavidWebb.

The above example could be written like this:

Webb webb = Webb.create(); webb.post("http://example.com/index.php") .param("param1", "a") .param("param2", "b") .param("param3", "c") .ensureSuccess() .asVoid(); 

You can find a list of alternative libraries on the link provided.

import java.net.*; public class Demo{ public static void main(){ String data = "data=Hello+World!"; URL url = new URL("http://localhost:8084/WebListenerServer/webListener"); HttpURLConnection con = (HttpURLConnection) url.openConnection(); con.setRequestMethod("POST"); con.setDoOutput(true); con.getOutputStream().write(data.getBytes("UTF-8")); con.getInputStream(); } } 

i have read above answers and have created a utility class to simplify HTTP request. i hope it will help you.

Method Call

 // send params with Hash Map HashMap<String, String> params = new HashMap<String, String>(); params.put("email","[email protected]"); params.put("password","12345"); //server url String url = "http://www.example.com"; // static class "HttpUtility" with static method "newRequest(url,method,callback)" HttpUtility.newRequest(url,HttpUtility.METHOD_POST,params, new HttpUtility.Callback() { @Override public void OnSuccess(String response) { // on success System.out.println("Server OnSuccess response="+response); } @Override public void OnError(int status_code, String message) { // on error System.out.println("Server OnError status_code="+status_code+" message="+message); } }); 

Utility Class

import java.io.*; import java.net.*; import java.util.HashMap; import java.util.Map; import static java.net.HttpURLConnection.HTTP_OK; public class HttpUtility { public static final int METHOD_GET = 0; // METHOD GET public static final int METHOD_POST = 1; // METHOD POST // Callback interface public interface Callback { // abstract methods public void OnSuccess(String response); public void OnError(int status_code, String message); } // static method public static void newRequest(String web_url, int method, HashMap < String, String > params, Callback callback) { // thread for handling async task new Thread(new Runnable() { @Override public void run() { try { String url = web_url; // write GET params,append with url if (method == METHOD_GET && params != null) { for (Map.Entry < String, String > item: params.entrySet()) { String key = URLEncoder.encode(item.getKey(), "UTF-8"); String value = URLEncoder.encode(item.getValue(), "UTF-8"); if (!url.contains("?")) { url += "?" + key + "=" + value; } else { url += "&" + key + "=" + value; } } } HttpURLConnection urlConnection = (HttpURLConnection) new URL(url).openConnection(); urlConnection.setUseCaches(false); urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); // handle url encoded form data urlConnection.setRequestProperty("charset", "utf-8"); if (method == METHOD_GET) { urlConnection.setRequestMethod("GET"); } else if (method == METHOD_POST) { urlConnection.setDoOutput(true); // write POST params urlConnection.setRequestMethod("POST"); } //write POST data if (method == METHOD_POST && params != null) { StringBuilder postData = new StringBuilder(); for (Map.Entry < String, String > item: params.entrySet()) { if (postData.length() != 0) postData.append('&'); postData.append(URLEncoder.encode(item.getKey(), "UTF-8")); postData.append('='); postData.append(URLEncoder.encode(String.valueOf(item.getValue()), "UTF-8")); } byte[] postDataBytes = postData.toString().getBytes("UTF-8"); urlConnection.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length)); urlConnection.getOutputStream().write(postDataBytes); } // server response code int responseCode = urlConnection.getResponseCode(); if (responseCode == HTTP_OK && callback != null) { BufferedReader reader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream())); StringBuilder response = new StringBuilder(); String line; while ((line = reader.readLine()) != null) { response.append(line); } // callback success callback.OnSuccess(response.toString()); reader.close(); // close BufferReader } else if (callback != null) { // callback error callback.OnError(responseCode, urlConnection.getResponseMessage()); } urlConnection.disconnect(); // disconnect connection } catch (IOException e) { e.printStackTrace(); if (callback != null) { // callback error callback.OnError(500, e.getLocalizedMessage()); } } } }).start(); // start thread } } 

I see some other answers have given the alternative, I personally think that intuitively you're doing the right thing ;). Sorry, at devoxx where several speakers have been ranting about this sort of thing.

That's why I personally use Apache's HTTPClient/HttpCore libraries to do this sort of work, I find their API to be easier to use than Java's native HTTP support. YMMV of course!

GET and POST method set like this... Two types for api calling 1)get() and 2) post() . get() method to get value from api json array to get value & post() method use in our data post in url and get response.

 public class HttpClientForExample { private final String USER_AGENT = "Mozilla/5.0"; public static void main(String[] args) throws Exception { HttpClientExample http = new HttpClientExample(); System.out.println("Testing 1 - Send Http GET request"); http.sendGet(); System.out.println("\nTesting 2 - Send Http POST request"); http.sendPost(); } // HTTP GET request private void sendGet() throws Exception { String url = "http://www.google.com/search?q=developer"; HttpClient client = new DefaultHttpClient(); HttpGet request = new HttpGet(url); // add request header request.addHeader("User-Agent", USER_AGENT); HttpResponse response = client.execute(request); System.out.println("\nSending 'GET' request to URL : " + url); System.out.println("Response Code : " + response.getStatusLine().getStatusCode()); BufferedReader rd = new BufferedReader( new InputStreamReader(response.getEntity().getContent())); StringBuffer result = new StringBuffer(); String line = ""; while ((line = rd.readLine()) != null) { result.append(line); } System.out.println(result.toString()); } // HTTP POST request private void sendPost() throws Exception { String url = "https://selfsolve.apple.com/wcResults.do"; HttpClient client = new DefaultHttpClient(); HttpPost post = new HttpPost(url); // add header post.setHeader("User-Agent", USER_AGENT); List<NameValuePair> urlParameters = new ArrayList<NameValuePair>(); urlParameters.add(new BasicNameValuePair("sn", "C02G8416DRJM")); urlParameters.add(new BasicNameValuePair("cn", "")); urlParameters.add(new BasicNameValuePair("locale", "")); urlParameters.add(new BasicNameValuePair("caller", "")); urlParameters.add(new BasicNameValuePair("num", "12345")); post.setEntity(new UrlEncodedFormEntity(urlParameters)); HttpResponse response = client.execute(post); System.out.println("\nSending 'POST' request to URL : " + url); System.out.println("Post parameters : " + post.getEntity()); System.out.println("Response Code : " + response.getStatusLine().getStatusCode()); BufferedReader rd = new BufferedReader( new InputStreamReader(response.getEntity().getContent())); StringBuffer result = new StringBuffer(); String line = ""; while ((line = rd.readLine()) != null) { result.append(line); } System.out.println(result.toString()); } } 

I had the same issue. I wanted to send data via POST. I used the following code:

 URL url = new URL("http://example.com/getval.php"); Map<String,Object> params = new LinkedHashMap<>(); params.put("param1", param1); params.put("param2", param2); StringBuilder postData = new StringBuilder(); for (Map.Entry<String,Object> param : params.entrySet()) { if (postData.length() != 0) postData.append('&'); postData.append(URLEncoder.encode(param.getKey(), "UTF-8")); postData.append('='); postData.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8")); } String urlParameters = postData.toString(); URLConnection conn = url.openConnection(); conn.setDoOutput(true); OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream()); writer.write(urlParameters); writer.flush(); String result = ""; String line; BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream())); while ((line = reader.readLine()) != null) { result += line; } writer.close(); reader.close() System.out.println(result); 

I used Jsoup for parse:

 Document doc = Jsoup.parseBodyFragment(value); Iterator<Element> opts = doc.select("option").iterator(); for (;opts.hasNext();) { Element item = opts.next(); if (item.hasAttr("value")) { System.out.println(item.attr("value")); } } 

Try this pattern:

public static PricesResponse getResponse(EventRequestRaw request) { // String urlParameters = "param1=a&param2=b&param3=c"; String urlParameters = Piping.serialize(request); HttpURLConnection conn = RestClient.getPOSTConnection(endPoint, urlParameters); PricesResponse response = null; try { // POST OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream()); writer.write(urlParameters); writer.flush(); // RESPONSE BufferedReader reader = new BufferedReader(new InputStreamReader((conn.getInputStream()), StandardCharsets.UTF_8)); String json = Buffering.getString(reader); response = (PricesResponse) Piping.deserialize(json, PricesResponse.class); writer.close(); reader.close(); } catch (Exception e) { e.printStackTrace(); } conn.disconnect(); System.out.println("PricesClient: " + response.toString()); return response; } public static HttpURLConnection getPOSTConnection(String endPoint, String urlParameters) { return RestClient.getConnection(endPoint, "POST", urlParameters); } public static HttpURLConnection getConnection(String endPoint, String method, String urlParameters) { System.out.println("ENDPOINT " + endPoint + " METHOD " + method); HttpURLConnection conn = null; try { URL url = new URL(endPoint); conn = (HttpURLConnection) url.openConnection(); conn.setRequestMethod(method); conn.setDoOutput(true); conn.setRequestProperty("Content-Type", "text/plain"); } catch (IOException e) { e.printStackTrace(); } return conn; } 

This answer covers the specific case of the POST Call using a Custom Java POJO.

Using maven dependency for Gson to serialize our Java Object to JSON.

Install Gson using the dependency below.

<dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId> <version>2.8.5</version> <scope>compile</scope> </dependency> 

For those using gradle can use the below

dependencies { implementation 'com.google.code.gson:gson:2.8.5' } 

Other imports used:

import org.apache.http.HttpResponse; import org.apache.http.client.methods.HttpPost; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.entity.*; import org.apache.http.impl.client.CloseableHttpClient; import com.google.gson.Gson; 

Now, we can go ahead and use the HttpPost provided by Apache

private CloseableHttpClient httpclient = HttpClients.createDefault(); HttpPost httppost = new HttpPost("https://example.com"); Product product = new Product(); //custom java object to be posted as Request Body Gson gson = new Gson(); String client = gson.toJson(product); httppost.setEntity(new StringEntity(client, ContentType.APPLICATION_JSON)); httppost.setHeader("RANDOM-HEADER", "headervalue"); //Execute and get the response. HttpResponse response = null; try { response = httpclient.execute(httppost); } catch (IOException e) { throw new InternalServerErrorException("Post fails"); } Response.Status responseStatus = Response.Status.fromStatusCode(response.getStatusLine().getStatusCode()); return Response.status(responseStatus).build(); 

The above code will return with the response code received from the POST Call

here i sent jsonobject as parameter //jsonobject={"name":"lucifer","pass":"abc"}//serverUrl = "http://192.168.100.12/testing" //host=192.168.100.12

 public static String getJson(String serverUrl,String host,String jsonobject){ StringBuilder sb = new StringBuilder(); String http = serverUrl; HttpURLConnection urlConnection = null; try { URL url = new URL(http); urlConnection = (HttpURLConnection) url.openConnection(); urlConnection.setDoOutput(true); urlConnection.setRequestMethod("POST"); urlConnection.setUseCaches(false); urlConnection.setConnectTimeout(50000); urlConnection.setReadTimeout(50000); urlConnection.setRequestProperty("Content-Type", "application/json"); urlConnection.setRequestProperty("Host", host); urlConnection.connect(); //You Can also Create JSONObject here OutputStreamWriter out = new OutputStreamWriter(urlConnection.getOutputStream()); out.write(jsonobject);// here i sent the parameter out.close(); int HttpResult = urlConnection.getResponseCode(); if (HttpResult == HttpURLConnection.HTTP_OK) { BufferedReader br = new BufferedReader(new InputStreamReader( urlConnection.getInputStream(), "utf-8")); String line = null; while ((line = br.readLine()) != null) { sb.append(line + "\n"); } br.close(); Log.e("new Test", "" + sb.toString()); return sb.toString(); } else { Log.e(" ", "" + urlConnection.getResponseMessage()); } } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } catch (JSONException e) { e.printStackTrace(); } finally { if (urlConnection != null) urlConnection.disconnect(); } return null; } 

Hello pls use this class to improve your post method

public static JSONObject doPostRequest(HashMap<String, String> data, String url) { try { RequestBody requestBody; MultipartBuilder mBuilder = new MultipartBuilder().type(MultipartBuilder.FORM); if (data != null) { for (String key : data.keySet()) { String value = data.get(key); Utility.printLog("Key Values", key + "-----------------" + value); mBuilder.addFormDataPart(key, value); } } else { mBuilder.addFormDataPart("temp", "temp"); } requestBody = mBuilder.build(); Request request = new Request.Builder() .url(url) .post(requestBody) .build(); OkHttpClient client = new OkHttpClient(); Response response = client.newCall(request).execute(); String responseBody = response.body().string(); Utility.printLog("URL", url); Utility.printLog("Response", responseBody); return new JSONObject(responseBody); } catch (UnknownHostException | UnsupportedEncodingException e) { JSONObject jsonObject=new JSONObject(); try { jsonObject.put("status","false"); jsonObject.put("message",e.getLocalizedMessage()); } catch (JSONException e1) { e1.printStackTrace(); } Log.e(TAG, "Error: " + e.getLocalizedMessage()); } catch (Exception e) { e.printStackTrace(); JSONObject jsonObject=new JSONObject(); try { jsonObject.put("status","false"); jsonObject.put("message",e.getLocalizedMessage()); } catch (JSONException e1) { e1.printStackTrace(); } Log.e(TAG, "Other Error: " + e.getLocalizedMessage()); } return null; } 

I higly recomend http-request built on apache http api.

For your case you can see example:

private static final HttpRequest<String.class> HTTP_REQUEST = HttpRequestBuilder.createPost("http://example.com/index.php", String.class) .responseDeserializer(ResponseDeserializer.ignorableDeserializer()) .build(); public void sendRequest(String request){ String parameters = request.split("\\?")[1]; ResponseHandler<String> responseHandler = HTTP_REQUEST.executeWithQuery(parameters); System.out.println(responseHandler.getStatusCode()); System.out.println(responseHandler.get()); //prints response body } 

If you are not interested in the response body

private static final HttpRequest<?> HTTP_REQUEST = HttpRequestBuilder.createPost("http://example.com/index.php").build(); public void sendRequest(String request){ ResponseHandler<String> responseHandler = HTTP_REQUEST.executeWithQuery(parameters); } 

For general sending post request with http-request: Read the documentation and see my answers HTTP POST request with JSON String in JAVA, Sending HTTP POST Request In Java, HTTP POST using JSON in Java

I took Boann's answer and used it to create a more flexible query string builder that supports lists and arrays, just like php's http_build_query method:

public static byte[] httpBuildQueryString(Map<String, Object> postsData) throws UnsupportedEncodingException { StringBuilder postData = new StringBuilder(); for (Map.Entry<String,Object> param : postsData.entrySet()) { if (postData.length() != 0) postData.append('&'); Object value = param.getValue(); String key = param.getKey(); if(value instanceof Object[] || value instanceof List<?>) { int size = value instanceof Object[] ? ((Object[])value).length : ((List<?>)value).size(); for(int i = 0; i < size; i++) { Object val = value instanceof Object[] ? ((Object[])value)[i] : ((List<?>)value).get(i); if(i>0) postData.append('&'); postData.append(URLEncoder.encode(key + "[" + i + "]", "UTF-8")); postData.append('='); postData.append(URLEncoder.encode(String.valueOf(val), "UTF-8")); } } else { postData.append(URLEncoder.encode(key, "UTF-8")); postData.append('='); postData.append(URLEncoder.encode(String.valueOf(value), "UTF-8")); } } return postData.toString().getBytes("UTF-8"); } 

Appears that you also have to callconnection.getOutputStream() "at least once" (as well as setDoOutput(true)) for it to treat it as a POST.

So the minimum required code is:

 URL url = new URL(urlString); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); //connection.setRequestMethod("POST"); this doesn't seem to do anything at all..so not useful connection.setDoOutput(true); // set it to POST...not enough by itself however, also need the getOutputStream call... connection.connect(); connection.getOutputStream().close(); 

You can even use "GET" style parameters in the urlString, surprisingly. Though that might confuse things.

You can also use NameValuePair apparently.

For those having trouble receiving the request on a php page using $_POST because you expect key-value pairs:

While all the answers where very helpful, I lacked some basic understanding on which string actually to post, since in the old apache HttpClient I used

new UrlEncodedFormEntity(nameValuePairs); (Java) 

and then could use $_POST in php do get the key-value pairs.

To my understanding now one has build that string manually before posting. So the string needs to look like

val data = "key1=val1&key2=val2" 

but instead just adding it to the url it is posted (in the header).

The alternative would be to use a json-string instead:

val data = "{\"key1\":\"val1\",\"key2\":\"val2\"}" // {"key1":"val1","key2":"val2"} 

and pull it in php without $_POST:

$json_params = file_get_contents('php://input'); // echo_p("Data: $json_params"); $data = json_decode($json_params, true); 

Here you find a sample code in Kotlin:

class TaskDownloadTest : AsyncTask<Void, Void, Void>() { override fun doInBackground(vararg params: Void): Void? { var urlConnection: HttpURLConnection? = null try { val postData = JsonObject() postData.addProperty("key1", "val1") postData.addProperty("key2", "val2") // reformat json to key1=value1&key2=value2 // keeping json because I may change the php part to interpret json requests, could be a HashMap instead val keys = postData.keySet() var request = "" keys.forEach { key -> // Log.i("data", key) request += "$key=${postData.get(key)}&" } request = request.replace("\"", "").removeSuffix("&") val requestLength = request.toByteArray().size // Warning in Android 9 you need to add a line in the application part of the manifest: android:usesCleartextTraffic="true" // https://stackoverflow.com/questions/45940861/android-8-cleartext-http-traffic-not-permitted val url = URL("http://10.0.2.2/getdata.php") urlConnection = url.openConnection() as HttpURLConnection // urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded") // apparently default // Not sure what these are for, I do not use them // urlConnection.setRequestProperty("Content-Type", "application/json") // urlConnection.setRequestProperty("Key","Value") urlConnection.readTimeout = 5000 urlConnection.connectTimeout = 5000 urlConnection.requestMethod = "POST" urlConnection.doOutput = true // urlConnection.doInput = true urlConnection.useCaches = false urlConnection.setFixedLengthStreamingMode(requestLength) // urlConnection.setChunkedStreamingMode(0) // if you do not want to handle request length which is fine for small requests val out = urlConnection.outputStream val writer = BufferedWriter( OutputStreamWriter( out, "UTF-8" ) ) writer.write(request) // writer.write("{\"key1\":\"val1\",\"key2\":\"val2\"}") // {"key1":"val1","key2":"val2"} JsonFormat or just postData.toString() for $json_params=file_get_contents('php://input'); json_decode($json_params, true); in php // writer.write("key1=val1&key2=val2") // key=value format for $_POST in php writer.flush() writer.close() out.close() val code = urlConnection.responseCode if (code != 200) { throw IOException("Invalid response from server: $code") } val rd = BufferedReader( InputStreamReader( urlConnection.inputStream ) ) var line = rd.readLine() while (line != null) { Log.i("data", line) line = rd.readLine() } } catch (e: Exception) { e.printStackTrace() } finally { urlConnection?.disconnect() } return null } } 

Now I had to do an HTTP request class, it is probably not the most efficient class, but it works. I collected some codes from this page and made it more dynamic.

Anyone who needs a complete code, I attached it below. For an example of how to use it, you can look at the main method.

Also, if you are willing to improve classes online, you are more than welcome to help me make this class better.

import java.net.*; import java.util.*; import java.nio.charset.*; import java.io.*; public class HttpRequest { String result = ""; HttpRequest(String _url, String _method, Map<String, String> _postData, String _contentType) { try { URL url = new URL( _url ); URLConnection con = url.openConnection(); HttpURLConnection http = (HttpURLConnection)con; http.setRequestMethod(_method); // PUT is another valid option http.setDoOutput(true); StringJoiner sj = new StringJoiner("&"); for(Map.Entry<String,String> entry : _postData.entrySet()) sj.add(URLEncoder.encode(entry.getKey(), "UTF-8") + "=" + entry.getValue()); //sj.add(URLEncoder.encode(entry.getKey(), "UTF-8") + "=" + URLEncoder.encode(entry.getValue())); byte[] out = sj.toString().getBytes(StandardCharsets.UTF_8); int length = out.length; http.setFixedLengthStreamingMode(length); http.setRequestProperty("Content-Type", _contentType); http.setRequestProperty( "charset", "utf-8"); http.setRequestProperty( "Content-Length", Integer.toString( length )); http.setInstanceFollowRedirects( false ); http.setUseCaches( false ); http.connect(); try(OutputStream os = http.getOutputStream()) { os.write(out); } if (http.getResponseCode() == HttpURLConnection.HTTP_OK) { try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(http.getInputStream()))) { String line; while ((line = bufferedReader.readLine()) != null) { result = result + line; } } } else { System.out.println("Bad response!"); } }catch (IOException e) { // writing exception to log e.printStackTrace(); } } HttpRequest(String _url, String _method, Map<String, String> _postData) { this(_url, _method, _postData, "text/html"); } HttpRequest(String _url, String _method) { this(_url, _method, new HashMap<String, String>()); } HttpRequest(String _url) { this(_url, "GET"); } public String toString() { return result; } public static void main(String[] args) { // TODO Auto-generated method stub Map<String, String> postData = new HashMap<String, String>(); postData.putIfAbsent("email", "[email protected]"); postData.putIfAbsent("password", "test"); HttpRequest result = new HttpRequest("https://httpbin.org/anything", "POST", postData, "application/x-www-form-urlencoded"); System.out.println(result.toString()); } } 

We can use the new HTTP Client API available in Java 11 and higher (except on Android).

var myData = "{ myParam1: 'This is cool' }"; // OR, "myParam1=abc&myParam2=xxx" var uri = URI.create("https://httpbin.org/post"); var client = HttpClient.newHttpClient(); var request = HttpRequest .newBuilder() .uri(uri) .version(HttpClient.Version.HTTP_2) .timeout(Duration.ofMinutes(1)) .header("Content-Type", "application/json") // OR text/plain .POST(HttpRequest.BodyPublishers.ofString(myData)) .build(); var response = client.send(request, HttpResponse.BodyHandlers.ofString()); 

The same request executed asynchronously:

var responseAsync = client .sendAsync(request, HttpResponse.BodyHandlers.ofString()) .thenApply(HttpResponse::body) .thenAccept(System.out::println); // responseAsync.join(); // Wait for completion 

To send data as multipart (multipart/form-data) format, see this solution.
To send data as url-encoded (application/x-www-form-urlencoded) format, see this solution.

See this article for examples and more information about HTTP Client API.

For Java standard library HTTP server, see this post.

Post a JSONObject:

//Create connection URL url = new URL(targetURL); connection = (HttpURLConnection) url.openConnection(); connection.setRequestMethod("POST"); //Set headers connection.setRequestProperty("Content-Type", "application/json;charset=UTF-8"); connection.setRequestProperty("Content-Language", "en-US"); connection.setRequestProperty("Accept", "application/json"); connection.setUseCaches(false); connection.setDoOutput(true); //Make the JSONObject JSONObject parent=new JSONObject(); parent.put("val1", "value1"); parent.put("val2", "value2"); parent.put("val3", 0); parent.put("val4", 1); //Send request OutputStream os = connection.getOutputStream(); os.write(parent.toString().getBytes("UTF-8")); os.close(); 

Read a JSONObject response:

public static String readInputStreamAsString(InputStream in) throws IOException { BufferedInputStream bis = new BufferedInputStream(in); ByteArrayOutputStream buf = new ByteArrayOutputStream(); int result = bis.read(); while(result != -1) { byte b = (byte)result; buf.write(b); result = bis.read(); } return buf.toString(); } //Get Response InputStream in = new BufferedInputStream(connection.getInputStream()); String result = readInputStreamAsString(in); jsonObject = new JSONObject(result); in.close();