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Send HTTPS request with JSON through Java [duplicate]

I would like to make a simple HTTP POST using JSON in Java.
Let's say the URL is www.site.com
and it takes in the value {"name":"myname","age":"20"} labeled as 'details' for example.
How would I go about creating the syntax for the POST?
I also can't seem to find a POST method in the JSON Javadocs.

Here is what you need to do:
Get the Apache HttpClient, this would enable you to make the required request
Create an HttpPost request with it and add the header application/x-www-form-urlencoded
Create a StringEntity that you will pass JSON to it
Execute the call
The code roughly looks like (you will still need to debug it and make it work):
// #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();
}

You can make use of Gson library to convert your java classes to JSON objects.
Create a pojo class for variables you want to send
as per above Example
{"name":"myname","age":"20"}
becomes
class pojo1
{
String name;
String age;
//generate setter and getters
}
once you set the variables in pojo1 class you can send that using the following code
String postUrl = "www.site.com";// put in your url
Gson gson = new Gson();
HttpClient httpClient = HttpClientBuilder.create().build();
HttpPost post = new HttpPost(postUrl);
StringEntity postingString = new StringEntity(gson.toJson(pojo1));//gson.tojson() converts your pojo to json
post.setEntity(postingString);
post.setHeader("Content-type", "application/json");
HttpResponse response = httpClient.execute(post);
and these are the imports
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClientBuilder;
and for GSON
import com.google.gson.Gson;

#momo's answer for Apache HttpClient, version 4.3.1 or later. I'm using JSON-Java to build my JSON object:
JSONObject json = new JSONObject();
json.put("someKey", "someValue");
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
try {
HttpPost request = new HttpPost("http://yoururl");
StringEntity params = new StringEntity(json.toString());
request.addHeader("content-type", "application/json");
request.setEntity(params);
httpClient.execute(request);
// handle response here...
} catch (Exception ex) {
// handle exception here
} finally {
httpClient.close();
}

It's probably easiest to use HttpURLConnection.
http://www.xyzws.com/Javafaq/how-to-use-httpurlconnection-post-data-to-web-server/139
You'll use JSONObject or whatever to construct your JSON, but not to handle the network; you need to serialize it and then pass it to an HttpURLConnection to POST.

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();
}

Try this code:
HttpClient httpClient = new DefaultHttpClient();
try {
HttpPost request = new HttpPost("http://yoururl");
StringEntity params =new StringEntity("details={\"name\":\"myname\",\"age\":\"20\"} ");
request.addHeader("content-type", "application/json");
request.addHeader("Accept","application/json");
request.setEntity(params);
HttpResponse response = httpClient.execute(request);
// handle response here...
}catch (Exception ex) {
// handle exception here
} finally {
httpClient.getConnectionManager().shutdown();
}

I found this question looking for solution about how to send post request from java client to Google Endpoints. Above answers, very likely correct, but not work in case of Google Endpoints.
Solution for Google Endpoints.
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.

You can use the following code with Apache HTTP:
String payload = "{\"name\": \"myname\", \"age\": \"20\"}";
post.setEntity(new StringEntity(payload, ContentType.APPLICATION_JSON));
response = client.execute(request);
Additionally you can create a json object and put in fields into the object like this
HttpPost post = new HttpPost(URL);
JSONObject payload = new JSONObject();
payload.put("name", "myName");
payload.put("age", "20");
post.setEntity(new StringEntity(payload.toString(), ContentType.APPLICATION_JSON));

For Java 11 you can use the new HTTP client:
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create("http://localhost/api"))
.header("Content-Type", "application/json")
.POST(ofInputStream(() -> getClass().getResourceAsStream(
"/some-data.json")))
.build();
client.sendAsync(request, BodyHandlers.ofString())
.thenApply(HttpResponse::body)
.thenAccept(System.out::println)
.join();
You can use publishers from InputStream, String, File. Converting JSON to a String or IS can be done with Jackson.

Java 11 standardization of HTTP client API that implements HTTP/2 and Web Socket, and can be found at java.net.HTTP.*:
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 with 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();
}

I recomend http-request built on apache http api.
HttpRequest<String> httpRequest = HttpRequestBuilder.createPost(yourUri, String.class)
.responseDeserializer(ResponseDeserializer.ignorableDeserializer()).build();
public void send(){
ResponseHandler<String> responseHandler = httpRequest.execute("details", yourJsonData);
int statusCode = responseHandler.getStatusCode();
String responseContent = responseHandler.orElse(null); // returns Content from response. If content isn't present returns null.
}
If you want send JSON as request body you can:
ResponseHandler<String> responseHandler = httpRequest.executeWithBody(yourJsonData);
I higly recomend read documentation before use.

Upload File from GWT to another domain , response is always null

I am uploading a File from GWT to a different domain
File Uploads well , But the response i sent from the server always reaches as "null" at the client side
response.setContentType("text/html");
response.setHeader("Access-Control-Allow-Origin", "*");
response.getWriter().print("TEST");
response is NULL only when i upload the file on a different domain ... (on same domain all is OK)
I also see this in GWT documentation
Tip:
The result html can be null as a result of submitting a form to a different domain.
http://www.gwtproject.org/javadoc/latest/com/google/gwt/user/client/ui/FormPanel.SubmitCompleteEvent.html
Is there any way I can receive back a response at my client side when i am uploading file to a different domain

There are 2 possible answer:
Use JSONP Builder
JsonpRequestBuilder requestBuilder = new JsonpRequestBuilder();
requestBuilder.requestObject(url, new AsyncCallback<FbUser>() {
#Override
public void onFailure(Throwable ex) {
throw SOMETHING_EXCEPTION(ex);
}
#Override
public void onSuccess(ResponseModel resp) {
if (resp.isError()) {
// on response error on something
log.error(resp.getError().getMessage())
log.error(resp.getError().getCode())
}
log.info(resp.getAnyData())
}
Not to use GWT to upload, rather use other client like apache HttpClient
public uploadFile() {
HttpClient httpClient = new DefaultHttpClient();
HttpContext localContext = new BasicHttpContext();
HttpPost httpPost = new HttpPost(url);
FileBody bin = new FileBody(new File(UPLOADED_FILE));
long size = bin.getContentLength();
MultipartEntity reqEntity = new MultipartEntity();
reqEntity.addPart("PART", bin);
String content = "-";
try {
httpPost.setEntity(reqEntity);
HttpResponse response = httpClient.execute(httpPost, localContext);
HttpEntity ent = response.getEntity();
InputStream st = ent.getContent();
StringWriter writer = new StringWriter();
IOUtils.copy(st, writer);
content = writer.toString();
} catch (IOException e) {
return "false";
}
return content;
}
Hope it helps

Java REST API: POST Method gets NULL parameters

I'm sending parameters from my android app to the backend and trying to retrieve the parameters sent by my android clients in my POST Method but I keep getting null parameters even though the clients are sending parameters which are not null.
Java POST Method:
#POST
#Produces({ "application/json" })
#Path("/login")
public LoginResponse Login(#FormParam("email") String email, #FormParam("password") String password) {
LoginResponse response = new LoginResponse();
if(email != null && password != null && email.length() != 0 && password.length() != 0){
//Detect if null or empty
//Code
}
return response;
}
Android Client:
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://MY_APP_NAME.appspot.com/user/login");
String json = "";
JSONObject jsonObject = new JSONObject();
try {
jsonObject.accumulate("email", "roger#gmail.com");
jsonObject.accumulate("password", "123");
json = jsonObject.toString();
StringEntity se = new StringEntity(json);
httppost.setEntity(se);
httppost.setHeader("Content-Type", "application/json");
httppost.setHeader("ACCEPT", "application/json");
HttpResponse httpResponse = httpclient.execute(httppost);
}
catch(Exception ex) { }
I believe the Content-Type of the method and the client is the same as well. Why am I not receiving the parameters from the Java Backend Method?
CHECKED:
The URL is correct and the connection is working
The Parameters sent by the app are not null

We hope i got you, try NameValuePair
public void postData() {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://www.yoursite.com/yourscript.php");
try {
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("id", "123"));
nameValuePairs.add(new BasicNameValuePair("string", "Hey"));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
} catch (ClientProtocolException e) {
// Catch Protocol Exception
} catch (IOException e) {
// Catch IOException
}
}

Just in case you have similar problems, I'd suggest using Fiddler
which is a free http inspector and debugger by which you can see the http request your app is sending to the backend server and the backend answer.
Best of luck

HTTPPOST returns 404 ANDROID

Im trying to post to a REST API json object but i keep getting responce 404 but the url is working fine. Can anyone tell me why is this happeninig?
Here is my code:
new AsyncTask<Void, Void, Void>() {
#Override
protected Void doInBackground(Void... params) {
HttpPost request = new HttpPost(
"http://grpsvil-webservice.si2001.it/RestChannelApp.svc/CheckCoupon");
// request.setHeader("Accept", "application/json");
request.setHeader("Accept", "application/json");
request.setHeader("Content-type", "application/json");
try {
// Build JSON string
JSONStringer vehicle = new JSONStringer()
.object()
.key("CouponVerificationCode")
.value("adf")
.key("ApiKey")
.value("adfadf123")
.key("Token")
.value("fgsg342==")
.endObject();
Log.v("--", vehicle.toString());
StringEntity entity = new StringEntity(vehicle.toString());
request.setEntity(entity);
// Send request to WCF service
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(request);
int resCode = response.getStatusLine().getStatusCode();
Log.v("--", response.getStatusLine().getStatusCode() + "");
if (resCode == 200) {
Toast.makeText(getApplicationContext(),
response.getStatusLine().getStatusCode() + "",
Toast.LENGTH_LONG).show();
BufferedReader in = new BufferedReader(
new InputStreamReader(response.getEntity()
.getContent()));
String line = "";
StringBuffer returnFromServer = new StringBuffer();
while ((line = in.readLine()) != null) {
returnFromServer.append(line);
}
// Toast what we got from server
Log.v("--", "!## " + returnFromServer.toString());
if (entity != null) {
entity.consumeContent();
}
}
} catch (Exception e) {
// TODO: handle exception
}
Intent i = new Intent(Splash.this, Login.class);
startActivity(i);
finish();
return null;
}

Endpoint not found.
Probably you write wrong methode url for this api

If you get all the WSDL from http://grpsvil-webservice.si2001.it/RestChannelApp.svc?WSDL you can see all the operations that you have defined.
CheckCoupon is not there, BUT there's a CheckPromotionalCode.
Could be that one?

The URL returns 404 not found. Just because it shows some fancy error text in the browser, doesn't mean the status code is 200 OK. This is the HTTP response that I get:
Status Code: 404 Not Found
Access-Control-Allow-Headers: Content-Type
Access-Control-Allow-Methods: GET,PUT,POST,DELETE
Age: 0
Cache-Control: private
Connection: Keep-Alive
Content-Length: 1565
Content-Type: text/html; charset=UTF-8
Date: Thu, 27 Feb 2014 14:58:03 GMT
Server: Microsoft-IIS/7.5
X-AspNet-Version: 4.0.30319
access-control-allow-origin: *
x-powered-by: ASP.NET

Try sending the verification code like this
ArrayList<NameValuePair> parms = new ArrayList<NameValuePair>();
parms.add(new BasicNameValuePair("CouponVerificationCode", adf));
parms.add(new BasicNameValuePair("ApiKey", adfadf123));
parms.add(new BasicNameValuePair("Token", fgsg342==));
httppost.setEntity(new UrlEncodedFormEntity(parms));
So your overall code will be
HttpPost request = new HttpPost(
"http://grpsvil-webservice.si2001.it/RestChannelApp.svc/CheckCoupon");
// request.setHeader("Accept", "application/json");
request.setHeader("Accept", "application/json");
request.setHeader("Content-type", "application/json");
try {
ArrayList<NameValuePair> parms = new ArrayList<NameValuePair>();
parms.add(new BasicNameValuePair("CouponVerificationCode", adf));
parms.add(new BasicNameValuePair("ApiKey", adfadf123));
parms.add(new BasicNameValuePair("Token", fgsg342==));
request.setEntity(new UrlEncodedFormEntity(parms));
request.setEntity(entity);
// Send request to WCF service
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(request);
int resCode = response.getStatusLine().getStatusCode();
Log.v("--", response.getStatusLine().getStatusCode() + "");

Android, Java: HTTP POST Request

I have to do a http post request to a web-service for authenticating the user with username and password. The Web-service guy gave me following information to construct HTTP Post request.
POST /login/dologin HTTP/1.1
Host: webservice.companyname.com
Content-Type: application/x-www-form-urlencoded
Content-Length: 48
id=username&num=password&remember=on&output=xml
The XML Response that i will be getting is
<?xml version="1.0" encoding="ISO-8859-1"?>
<login>
<message><![CDATA[]]></message>
<status><![CDATA[true]]></status>
<Rlo><![CDATA[Username]]></Rlo>
<Rsc><![CDATA[9L99PK1KGKSkfMbcsxvkF0S0UoldJ0SU]]></Rsc>
<Rm><![CDATA[b59031b85bb127661105765722cd3531==AO1YjN5QDM5ITM]]></Rm>
<Rl><![CDATA[username#company.com]]></Rl>
<uid><![CDATA[3539145]]></uid>
<Rmu><![CDATA[f8e8917f7964d4cc7c4c4226f060e3ea]]></Rmu>
</login>
This is what i am doing HttpPost postRequest = new HttpPost(urlString); How do i construct the rest of the parameters?

Here's an example previously found at androidsnippets.com (the site is currently not maintained anymore).
// Create a new HttpClient and Post Header
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://www.yoursite.com/script.php");
try {
// Add your data
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("id", "12345"));
nameValuePairs.add(new BasicNameValuePair("stringdata", "AndDev is Cool!"));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
} catch (IOException e) {
// TODO Auto-generated catch block
}
So, you can add your parameters as BasicNameValuePair.
An alternative is to use (Http)URLConnection. See also Using java.net.URLConnection to fire and handle HTTP requests. This is actually the preferred method in newer Android versions (Gingerbread+). See also this blog, this developer doc and Android's HttpURLConnection javadoc.

to #BalusC answer I would add how to convert the response in a String:
HttpResponse response = client.execute(request);
HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream instream = entity.getContent();
String result = RestClient.convertStreamToString(instream);
Log.i("Read from server", result);
}
Here is an example of convertStramToString.

Please consider using HttpPost. Adopt from this: http://www.javaworld.com/javatips/jw-javatip34.html
URLConnection connection = new URL("http://webservice.companyname.com/login/dologin").openConnection();
// Http Method becomes POST
connection.setDoOutput(true);
// Encode according to application/x-www-form-urlencoded specification
String content =
"id=" + URLEncoder.encode ("username") +
"&num=" + URLEncoder.encode ("password") +
"&remember=" + URLEncoder.encode ("on") +
"&output=" + URLEncoder.encode ("xml");
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
// Try this should be the length of you content.
// it is not neccessary equal to 48.
// content.getBytes().length is not neccessarily equal to content.length() if the String contains non ASCII characters.
connection.setRequestProperty("Content-Length", content.getBytes().length);
// Write body
OutputStream output = connection.getOutputStream();
output.write(content.getBytes());
output.close();
You will need to catch the exception yourself.

I'd rather recommend you to use Volley to make GET, PUT, POST... requests.
First, add dependency in your gradle file.
compile 'com.he5ed.lib:volley:android-cts-5.1_r4'
Now, use this code snippet to make requests.
RequestQueue queue = Volley.newRequestQueue(getApplicationContext());
StringRequest postRequest = new StringRequest( com.android.volley.Request.Method.POST, mURL,
new Response.Listener<String>()
{
#Override
public void onResponse(String response) {
// response
Log.d("Response", response);
}
},
new Response.ErrorListener()
{
#Override
public void onErrorResponse(VolleyError error) {
// error
Log.d("Error.Response", error.toString());
}
}
) {
#Override
protected Map<String, String> getParams()
{
Map<String, String> params = new HashMap<String, String>();
//add your parameters here as key-value pairs
params.put("username", username);
params.put("password", password);
return params;
}
};
queue.add(postRequest);

Try HttpClient for Java:
http://hc.apache.org/httpclient-3.x/

You can reuse the implementation I added to ACRA:
http://code.google.com/p/acra/source/browse/tags/REL-3_1_0/CrashReport/src/org/acra/HttpUtils.java?r=236
(See the doPost(Map, Url) method, working over http and https even with self signed certs)

I used the following code to send HTTP POST from my android client app to C# desktop app on my server:
// Create a new HttpClient and Post Header
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://www.yoursite.com/script.php");
try {
// Add your data
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("id", "12345"));
nameValuePairs.add(new BasicNameValuePair("stringdata", "AndDev is Cool!"));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
} catch (IOException e) {
// TODO Auto-generated catch block
}
I worked on reading the request from a C# app on my server (something like a web server little application).
I managed to read request posted data using the following code:
server = new HttpListener();
server.Prefixes.Add("http://*:50000/");
server.Start();
HttpListenerContext context = server.GetContext();
HttpListenerContext context = obj as HttpListenerContext;
HttpListenerRequest request = context.Request;
StreamReader sr = new StreamReader(request.InputStream);
string str = sr.ReadToEnd();

HTTP request POST in java does not dump the answer?
public class HttpClientExample
{
private final String USER_AGENT = "Mozilla/5.0";
public static void main(String[] args) throws Exception
{
HttpClientExample http = new HttpClientExample();
System.out.println("\nTesting 1 - Send Http POST request");
http.sendPost();
}
// HTTP POST request
private void sendPost() throws Exception {
String url = "http://www.wmtechnology.org/Consultar-RUC/index.jsp";
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(url);
// add header
post.setHeader("User-Agent", USER_AGENT);
List<NameValuePair> urlParameters = new ArrayList<>();
urlParameters.add(new BasicNameValuePair("accion", "busqueda"));
urlParameters.add(new BasicNameValuePair("modo", "1"));
urlParameters.add(new BasicNameValuePair("nruc", "10469415177"));
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()));
StringBuilder result = new StringBuilder();
String line = "";
while ((line = rd.readLine()) != null)
{
result.append(line);
System.out.println(line);
}
}
}
This is the web: http://www.wmtechnology.org/Consultar-RUC/index.jsp,from you can consult Ruc without captcha. Your opinions are welcome!