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Convert Jersey Client to HttpUrlConnection

I have a Jersey client that retrieves a jwt token from an API.
This is the code
public static final String INFO_ENDPOINT = "http://10.1.9.10:7100/Info/";
private static final String INFO_USERNAME = "user";
private static final String INFO_PASSWORD = "password";
private static final String AUTH_PATH = "auth";
private String token;
private final Client client;
public JerseyClient() {
ClientConfig cc = new DefaultClientConfig();
cc.getClasses().add(MultiPartWriter.class);
client = Client.create(cc);
}
public void authenticate() {
try {
WebResource resource = client.resource(INFO_ENDPOINT + AUTH_PATH);
StringBuilder sb = new StringBuilder();
sb.append("{\"username\":\"" + INFO_USERNAME + "\",");
sb.append("\"password\":\"" + INFO_PASSWORD + "\"}");
ClientResponse clientResp = resource.type("application/json")
.post(ClientResponse.class, sb.toString());
String content = clientResp.getEntity(String.class);
System.out.println("Response:" + content);
token = content.substring(content.indexOf("\"token\":") + 9,
content.lastIndexOf("\""));
System.out.println("token " + token);
} catch (ClientHandlerException | UniformInterfaceException e) {
}
}
The above code returns a jwt token that is then used as a key for another call.
I am trying to convert it to use HttpUrlConnection. But that does not seem to work
This is what I have tried. It does not give an error, but does not return the token either. The response is empty
try {
URL url = new URL("http://10.1.9.10:7100/Info/auth");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json");
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty("accept", "application/json");
String input = "{\"username\":user,\"password\":\"password\"}";
OutputStream os = conn.getOutputStream();
os.write(input.getBytes());
os.flush();
if (conn.getResponseCode() != 200) {
throw new RuntimeException("Failed : HTTP error code : "
+ conn.getResponseCode());
}
BufferedReader br = new BufferedReader(new InputStreamReader(
(conn.getInputStream())));
String output;
System.out.println("Output from Server .... \n");
while ((output = br.readLine()) != null) {
System.out.println(output);
}
conn.disconnect();
} catch (IOException e) {
}
My problem is I am not able to translate .post(ClientResponse.class, sb.toString()) to HttpUrlConnection.
What am I missing, or what am I doing wrong?
Thanks

The issue is resolved. The code works as is.
The problem was I was missing quotes for json value String
Should have been
String input = "{\"username\":\"user\",\"password\":\"password\"}";

Request to web services restful with pojo object and method post

I created a restful web service:
#POST
#Path("grd")
#Consumes("application/json")
#Produces("text/plain")
public String guardarDato(PostParams jsonObject) {
/*
something here
}
PostParams is a pojo:
public class PostParams {
private final Map<String, String> postParamsList;
public PostParams() {
postParamsList = new HashMap<>();
}
public void addParameter(String name, String value) {
postParamsList.put(name, value);
}
public String getPostParamsList(String name) {
return postParamsList.get(name);
}
public void getPostParamsMap() {
if (postParamsList.isEmpty()) {
System.out.println("Parametros vacios");
} else {
for (String key : postParamsList.keySet()) {
System.out.println("Clave: " + key + " -> Valor: " + postParamsList.get(key));
}
}
}
}
I am trying to call this web service from android with HttpUrlConnection,
but my object is null pojo in my web services.
try {
URL url = new URL("http://localhost:8080/VfqCh/hgt/opli/grd");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json");
// conn.setRequestProperty("Accept", "application/json");
PostParams postParams = new PostParams();
postParams.addParameter("h", "51rt3");
postParams.addParameter("x", "dsfsd8698sdfs");
postParams.addParameter("ax", "Dairon");
postParams.addParameter("tf", "D");
// String input = "{\"qty\":100,\"name\":\"iPad 4\"}";
Gson gson = new Gson();
String gString = gson.toJson(postParams, PostParams.class);
try (OutputStreamWriter printout = new OutputStreamWriter(conn.getOutputStream())) {
printout.write(gString);
printout.flush();
}
if (conn.getResponseCode() != HttpURLConnection.HTTP_OK) {
throw new RuntimeException("Failed : HTTP error code : "
+ conn.getResponseCode());
}
BufferedReader br = new BufferedReader(new InputStreamReader(
(conn.getInputStream())));
String output;
System.out.println("Output from Server .... \n");
while ((output = br.readLine()) != null) {
System.out.println(output);
}
conn.disconnect();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
The information is send to web services but the object is null.
if I change the type of object that is receive in the web services if it works!:
#POST
#Path("grd")
#Consumes("application/json")
#Produces("text/plain")
public String guardarDato(String jsonObject) {
/*
something here
}
But i need receive an object in the web services! It is possible?

You made a POJO for a HashMap, but you could have just used a JsonObject that is already provided by Gson and basically acts like a HashMap. Then, you toString it, and you have a JSON string you can send to a server. There is no need for Gson.toJson and worrying if it was converted correctly.
Your server is accepting a JSON string, as defined by
#Consumes("application/json")
Therefore, this should be the method
public String guardarDato(String jsonObject) {
You will need to add Gson as a dependency for your server, then you should be able to get the JSON to an object with something like PostParams params = Gson.fromJson(jsonObject, PostParams.class) assuming the data was sent correctly from the client side, but as stated earlier, your POJO doesn't add much functionality on top of just a JsonObject or plain HashMap

POST to Google Cloud Messaging with Retrofit

I am using HttpURLConnection for POST message to GCM like:
try {
URL url = new URL(GCM_SERVER_URL);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json");
conn.setRequestProperty("Authorization", "key=" + apiKey);
conn.setDoOutput(true);
ObjectMapper mapper = new ObjectMapper();
mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
DataOutputStream dataOutputStream = new DataOutputStream(conn.getOutputStream());
mapper.writeValue(dataOutputStream, content);
dataOutputStream.flush();
dataOutputStream.close();
// Get the response
int responseCode = conn.getResponseCode();
System.out.println("\nSending 'POST' request to URL : " + url);
System.out.println("Response Code : " + responseCode);
BufferedReader in = new BufferedReader(
new InputStreamReader(conn.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
System.out.println(response.toString());
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
And now i want to use Retrofit for POST message to GCM
I tried:
#Headers("Content-Type: application/json")
#FormUrlEncoded
#POST("/")
public GCMObject GCMAuthorization(#Header("Authorization") String apiKey,
#Body String data
);
I sent json string in data, But it always failed with this error:
#Body parameters cannot be used with form or multi-part encoding.
I did't found any solution, how can i fix it?

#FormUrlEncoded is used when you want to send form parameters. These parameters are encoded as the body, you can have your own. It does not look like you are using and form parameters, so remove #FormUrlEncoded. Also, I recommend using GSON to convert your POJO to JSON for the #Body. It looks like you are using retrofit 1 and trying to send a raw String. Retrofit will try to JSON encode that for you, which means you'll end up with the object you send wrapped in "...". If you want to send a raw string, take a look at this answer for your options in retrofit 1.

Java - sending HTTP parameters via POST method easily

I am successfully using this code to send HTTP requests with some parameters via GET method
void sendRequest(String request)
{
// i.e.: request = "http://example.com/index.php?param1=a&param2=b&param3=c";
URL url = new URL(request);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setInstanceFollowRedirects(false);
connection.setRequestMethod("GET");
connection.setRequestProperty("Content-Type", "text/plain");
connection.setRequestProperty("charset", "utf-8");
connection.connect();
}
Now I may need to send the parameters (i.e. param1, param2, param3) via POST method because they are very long.
I was thinking to add an extra parameter to that method (i.e. String httpMethod).
How can I change the code above as little as possible to be able to send paramters either via GET or POST?
I was hoping that changing
connection.setRequestMethod("GET");
to
connection.setRequestMethod("POST");
would have done the trick, but the parameters are still sent via GET method.
Has HttpURLConnection got any method that would help?
Is there any helpful Java construct?
Any help would be very much appreciated.

In a GET request, the parameters are sent as part of the URL.
In a POST request, the parameters are sent as a body of the request, after the headers.
To do a POST with HttpURLConnection, you need to write the parameters to the connection after you have opened the connection.
This code should get you started:
String urlParameters = "param1=a&param2=b&param3=c";
byte[] postData = urlParameters.getBytes( StandardCharsets.UTF_8 );
int postDataLength = postData.length;
String request = "http://example.com/index.php";
URL url = new URL( request );
HttpURLConnection conn= (HttpURLConnection) url.openConnection();
conn.setDoOutput( true );
conn.setInstanceFollowRedirects( false );
conn.setRequestMethod( "POST" );
conn.setRequestProperty( "Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty( "charset", "utf-8");
conn.setRequestProperty( "Content-Length", Integer.toString( postDataLength ));
conn.setUseCaches( false );
try( DataOutputStream wr = new DataOutputStream( conn.getOutputStream())) {
wr.write( postData );
}

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", "fishie#seamail.example.com");
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","me#example.com");
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");
}

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", "test#test.com");
postData.putIfAbsent("password", "test");
HttpRequest result = new HttpRequest("https://httpbin.org/anything", "POST", postData, "application/x-www-form-urlencoded");
System.out.println(result.toString());
}
}

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.

How do I make an http request using cookies on Android?

I'd like to make an http request to a remote server while properly handling cookies (eg. storing cookies sent by the server, and sending those cookies when I make subsequent requests). It'd be nice to preserve any and all cookies, but really the only one I care about is the session cookie.
With java.net, it appears that the preferred way to do this is using java.net.CookieHandler (abstract base class) and java.net.CookieManager (concrete implementation). Android has java.net.CookieHandler, but it does not seem to have java.net.CookieManager.
I could code it all by hand by inspecting http headers, but it seems like there must be an easier way.
What is the proper way to make http requests on Android while preserving cookies?

It turns out that Google Android ships with Apache HttpClient 4.0, and I was able to figure out how to do it using the "Form based logon" example in the HttpClient docs:
https://github.com/apache/httpcomponents-client/blob/master/httpclient5/src/test/java/org/apache/hc/client5/http/examples/ClientFormLogin.java
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.cookie.Cookie;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
/**
* A example that demonstrates how HttpClient APIs can be used to perform
* form-based logon.
*/
public class ClientFormLogin {
public static void main(String[] args) throws Exception {
DefaultHttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet("https://portal.sun.com/portal/dt");
HttpResponse response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
System.out.println("Login form get: " + response.getStatusLine());
if (entity != null) {
entity.consumeContent();
}
System.out.println("Initial set of cookies:");
List<Cookie> cookies = httpclient.getCookieStore().getCookies();
if (cookies.isEmpty()) {
System.out.println("None");
} else {
for (int i = 0; i < cookies.size(); i++) {
System.out.println("- " + cookies.get(i).toString());
}
}
HttpPost httpost = new HttpPost("https://portal.sun.com/amserver/UI/Login?" +
"org=self_registered_users&" +
"goto=/portal/dt&" +
"gotoOnFail=/portal/dt?error=true");
List <NameValuePair> nvps = new ArrayList <NameValuePair>();
nvps.add(new BasicNameValuePair("IDToken1", "username"));
nvps.add(new BasicNameValuePair("IDToken2", "password"));
httpost.setEntity(new UrlEncodedFormEntity(nvps, HTTP.UTF_8));
response = httpclient.execute(httpost);
entity = response.getEntity();
System.out.println("Login form get: " + response.getStatusLine());
if (entity != null) {
entity.consumeContent();
}
System.out.println("Post logon cookies:");
cookies = httpclient.getCookieStore().getCookies();
if (cookies.isEmpty()) {
System.out.println("None");
} else {
for (int i = 0; i < cookies.size(); i++) {
System.out.println("- " + cookies.get(i).toString());
}
}
// When HttpClient instance is no longer needed,
// shut down the connection manager to ensure
// immediate deallocation of all system resources
httpclient.getConnectionManager().shutdown();
}
}

A cookie is just another HTTP header. You can always set it while making a HTTP call with the apache library or with HTTPUrlConnection. Either way you should be able to read and set HTTP cookies in this fashion.
You can read this article for more information.
I can share my peace of code to demonstrate how easy you can make it.
public static String getServerResponseByHttpGet(String url, String token) {
try {
HttpClient client = new DefaultHttpClient();
HttpGet get = new HttpGet(url);
get.setHeader("Cookie", "PHPSESSID=" + token + ";");
Log.d(TAG, "Try to open => " + url);
HttpResponse httpResponse = client.execute(get);
int connectionStatusCode = httpResponse.getStatusLine().getStatusCode();
Log.d(TAG, "Connection code: " + connectionStatusCode + " for request: " + url);
HttpEntity entity = httpResponse.getEntity();
String serverResponse = EntityUtils.toString(entity);
Log.d(TAG, "Server response for request " + url + " => " + serverResponse);
if(!isStatusOk(connectionStatusCode))
return null;
return serverResponse;
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}

Since Apache library is deprecated, for those who want to use HttpURLConncetion , I wrote this class to send Get and Post Request with the help of this answer:
public class WebService {
static final String COOKIES_HEADER = "Set-Cookie";
static final String COOKIE = "Cookie";
static CookieManager msCookieManager = new CookieManager();
private static int responseCode;
public static String sendPost(String requestURL, String urlParameters) {
URL url;
String response = "";
try {
url = new URL(requestURL);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(15000);
conn.setConnectTimeout(15000);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json; charset=utf-8");
if (msCookieManager.getCookieStore().getCookies().size() > 0) {
//While joining the Cookies, use ',' or ';' as needed. Most of the server are using ';'
conn.setRequestProperty(COOKIE ,
TextUtils.join(";", msCookieManager.getCookieStore().getCookies()));
}
conn.setDoInput(true);
conn.setDoOutput(true);
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(os, "UTF-8"));
if (urlParameters != null) {
writer.write(urlParameters);
}
writer.flush();
writer.close();
os.close();
Map<String, List<String>> headerFields = conn.getHeaderFields();
List<String> cookiesHeader = headerFields.get(COOKIES_HEADER);
if (cookiesHeader != null) {
for (String cookie : cookiesHeader) {
msCookieManager.getCookieStore().add(null, HttpCookie.parse(cookie).get(0));
}
}
setResponseCode(conn.getResponseCode());
if (getResponseCode() == HttpsURLConnection.HTTP_OK) {
String line;
BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
while ((line = br.readLine()) != null) {
response += line;
}
} else {
response = "";
}
} catch (Exception e) {
e.printStackTrace();
}
return response;
}
// HTTP GET request
public static String sendGet(String url) throws Exception {
URL obj = new URL(url);
HttpURLConnection con = (HttpURLConnection) obj.openConnection();
// optional default is GET
con.setRequestMethod("GET");
//add request header
con.setRequestProperty("User-Agent", "Mozilla");
/*
* https://stackoverflow.com/questions/16150089/how-to-handle-cookies-in-httpurlconnection-using-cookiemanager
* Get Cookies form cookieManager and load them to connection:
*/
if (msCookieManager.getCookieStore().getCookies().size() > 0) {
//While joining the Cookies, use ',' or ';' as needed. Most of the server are using ';'
con.setRequestProperty(COOKIE ,
TextUtils.join(";", msCookieManager.getCookieStore().getCookies()));
}
/*
* https://stackoverflow.com/questions/16150089/how-to-handle-cookies-in-httpurlconnection-using-cookiemanager
* Get Cookies form response header and load them to cookieManager:
*/
Map<String, List<String>> headerFields = con.getHeaderFields();
List<String> cookiesHeader = headerFields.get(COOKIES_HEADER);
if (cookiesHeader != null) {
for (String cookie : cookiesHeader) {
msCookieManager.getCookieStore().add(null, HttpCookie.parse(cookie).get(0));
}
}
int responseCode = con.getResponseCode();
BufferedReader in = new BufferedReader(
new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
return response.toString();
}
public static void setResponseCode(int responseCode) {
WebService.responseCode = responseCode;
Log.i("Milad", "responseCode" + responseCode);
}
public static int getResponseCode() {
return responseCode;
}
}

I do not work with google android but I think you'll find it's not that hard to get this working. If you read the relevant bit of the java tutorial you'll see that a registered cookiehandler gets callbacks from the HTTP code.
So if there is no default (have you checked if CookieHandler.getDefault() really is null?) then you can simply extend CookieHandler, implement put/get and make it work pretty much automatically. Be sure to consider concurrent access and the like if you go that route.
edit: Obviously you'd have to set an instance of your custom implementation as the default handler through CookieHandler.setDefault() to receive the callbacks. Forgot to mention that.