Error while sending data with POST request in Android - java

I always get the same error while sending username and password to server. I need to send data as content type:form-data, because server isn't responding on any other type. I tested in postman and it's ok, but when I am trying to send it in code, it's not working. Can someone help me, thanks!!
public class Login extends AsyncTask<String, Void, Void> {
String userName;
String password;
public Login(String user, String pass) {
userName = user;
password = pass;
}
protected void onPreExecute() {
super.onPreExecute();
}
protected Void doInBackground(String... params) {
OkHttpClient client = new OkHttpClient().newBuilder()
.build();
MediaType mediaType = MediaType.parse("text/plain");
RequestBody body = new MultipartBody.Builder().setType(MultipartBody.FORM)
.addFormDataPart("user",userName)
.addFormDataPart("pass",password)
.build();
Request request = new Request.Builder()
.url("http://www.autotrack.rs/android_juzna_backa/login.php")
.method("POST", body)
.build();
try {
Response response = client.newCall(request).execute();
System.out.println(response.body().string());
} catch (IOException e) {
e.printStackTrace();
}
try {
Call call = client.newCall(request);
Response response = call.execute();
System.out.println(response.body().string());
}catch (Exception m)
{
Log.d("Mytag", m.getMessage());
}
if(!response.isSuccessful())
{
try {
throw new IOException("Unexpected: "+response);
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean okhttp3.Response.isSuccessful()' on a null object reference

This code works perfectly fine for me:
OkHttpClient client = new OkHttpClient().newBuilder()
.build();
MediaType mediaType = MediaType.parse("text/plain");
RequestBody body = new MultipartBody.Builder().setType(MultipartBody.FORM)
.addFormDataPart("user","pera")
.addFormDataPart("pass","1111")
.build();
Request request = new Request.Builder()
.url("http://www.autotrack.rs/android_juzna_backa/login.php")
.method("POST", body)
.build();
Response response = client.newCall(request).execute();
In your code I see that you execute the same request twice, maybe this is the issue?

Related

Android java make call to url [duplicate]

I have searched everywhere but I couldn't find my answer, is there a way to make a simple HTTP request? I want to request a PHP page / script on one of my websites but I don't want to show the webpage.
If possible I even want to do it in the background (in a BroadcastReceiver)
UPDATE
This is a very old answer. I definitely won't recommend Apache's client anymore. Instead use either:
Retrofit
OkHttp
Volley
HttpUrlConnection
Original Answer
First of all, request a permission to access network, add following to your manifest:
<uses-permission android:name="android.permission.INTERNET" />
Then the easiest way is to use Apache http client bundled with Android:
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = httpclient.execute(new HttpGet(URL));
StatusLine statusLine = response.getStatusLine();
if(statusLine.getStatusCode() == HttpStatus.SC_OK){
ByteArrayOutputStream out = new ByteArrayOutputStream();
response.getEntity().writeTo(out);
String responseString = out.toString();
out.close();
//..more logic
} else{
//Closes the connection.
response.getEntity().getContent().close();
throw new IOException(statusLine.getReasonPhrase());
}
If you want it to run on separate thread I'd recommend extending AsyncTask:
class RequestTask extends AsyncTask<String, String, String>{
#Override
protected String doInBackground(String... uri) {
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response;
String responseString = null;
try {
response = httpclient.execute(new HttpGet(uri[0]));
StatusLine statusLine = response.getStatusLine();
if(statusLine.getStatusCode() == HttpStatus.SC_OK){
ByteArrayOutputStream out = new ByteArrayOutputStream();
response.getEntity().writeTo(out);
responseString = out.toString();
out.close();
} else{
//Closes the connection.
response.getEntity().getContent().close();
throw new IOException(statusLine.getReasonPhrase());
}
} catch (ClientProtocolException e) {
//TODO Handle problems..
} catch (IOException e) {
//TODO Handle problems..
}
return responseString;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
//Do anything with response..
}
}
You then can make a request by:
new RequestTask().execute("http://stackoverflow.com");
unless you have an explicit reason to choose the Apache HttpClient, you should prefer java.net.URLConnection. you can find plenty of examples of how to use it on the web.
we've also improved the Android documentation since your original post: http://developer.android.com/reference/java/net/HttpURLConnection.html
and we've talked about the trade-offs on the official blog: http://android-developers.blogspot.com/2011/09/androids-http-clients.html
Note: The Apache HTTP Client bundled with Android is now deprecated in favor of HttpURLConnection. Please see the Android Developers Blog for more details.
Add <uses-permission android:name="android.permission.INTERNET" /> to your manifest.
You would then retrieve a web page like so:
URL url = new URL("http://www.android.com/");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
try {
InputStream in = new BufferedInputStream(urlConnection.getInputStream());
readStream(in);
}
finally {
urlConnection.disconnect();
}
I also suggest running it on a separate thread:
class RequestTask extends AsyncTask<String, String, String>{
#Override
protected String doInBackground(String... uri) {
String responseString = null;
try {
URL url = new URL(myurl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
if(conn.getResponseCode() == HttpsURLConnection.HTTP_OK){
// Do normal input or output stream reading
}
else {
response = "FAILED"; // See documentation for more info on response handling
}
} catch (ClientProtocolException e) {
//TODO Handle problems..
} catch (IOException e) {
//TODO Handle problems..
}
return responseString;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
//Do anything with response..
}
}
See the documentation for more information on response handling and POST requests.
The most simple way is using the Android lib called Volley
Volley offers the following benefits:
Automatic scheduling of network requests. Multiple concurrent network
connections. Transparent disk and memory response caching with
standard HTTP cache coherence. Support for request prioritization.
Cancellation request API. You can cancel a single request, or you can
set blocks or scopes of requests to cancel. Ease of customization, for
example, for retry and backoff. Strong ordering that makes it easy to
correctly populate your UI with data fetched asynchronously from the
network. Debugging and tracing tools.
You can send a http/https request as simple as this:
// Instantiate the RequestQueue.
RequestQueue queue = Volley.newRequestQueue(this);
String url ="http://www.yourapi.com";
JsonObjectRequest request = new JsonObjectRequest(url, null,
new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
if (null != response) {
try {
//handle your response
} catch (JSONException e) {
e.printStackTrace();
}
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
}
});
queue.add(request);
In this case, you needn't consider "running in the background" or "using cache" yourself as all of these has already been done by Volley.
Use Volley as suggested above. Add following into build.gradle (Module: app)
implementation 'com.android.volley:volley:1.1.1'
Add following into AndroidManifest.xml:
<uses-permission android:name="android.permission.INTERNET" />
And add following to you Activity code:
public void httpCall(String url) {
RequestQueue queue = Volley.newRequestQueue(this);
StringRequest stringRequest = new StringRequest(Request.Method.GET, url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
// enjoy your response
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
// enjoy your error status
}
});
queue.add(stringRequest);
}
It replaces http client and it is very simple.
private String getToServer(String service) throws IOException {
HttpGet httpget = new HttpGet(service);
ResponseHandler<String> responseHandler = new BasicResponseHandler();
return new DefaultHttpClient().execute(httpget, responseHandler);
}
Regards
With a thread:
private class LoadingThread extends Thread {
Handler handler;
LoadingThread(Handler h) {
handler = h;
}
#Override
public void run() {
Message m = handler.obtainMessage();
try {
BufferedReader in =
new BufferedReader(new InputStreamReader(url.openStream()));
String page = "";
String inLine;
while ((inLine = in.readLine()) != null) {
page += inLine;
}
in.close();
Bundle b = new Bundle();
b.putString("result", page);
m.setData(b);
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
handler.sendMessage(m);
}
}
As none of the answers described a way to perform requests with OkHttp, which is very popular http client nowadays for Android and Java in general, I am going to provide a simple example:
//get an instance of the client
OkHttpClient client = new OkHttpClient();
//add parameters
HttpUrl.Builder urlBuilder = HttpUrl.parse("https://www.example.com").newBuilder();
urlBuilder.addQueryParameter("query", "stack-overflow");
String url = urlBuilder.build().toString();
//build the request
Request request = new Request.Builder().url(url).build();
//execute
Response response = client.newCall(request).execute();
The clear advantage of this library is that it abstracts us from some low level details, providing more friendly and secure ways to interact with them. The syntax is also simplified and permits to write nice code.
I made this for a webservice to requerst on URL, using a Gson lib:
Client:
public EstabelecimentoList getListaEstabelecimentoPorPromocao(){
EstabelecimentoList estabelecimentoList = new EstabelecimentoList();
try{
URL url = new URL("http://" + Conexao.getSERVIDOR()+ "/cardapio.online/rest/recursos/busca_estabelecimento_promocao_android");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
if (con.getResponseCode() != 200) {
throw new RuntimeException("HTTP error code : "+ con.getResponseCode());
}
BufferedReader br = new BufferedReader(new InputStreamReader((con.getInputStream())));
estabelecimentoList = new Gson().fromJson(br, EstabelecimentoList.class);
con.disconnect();
} catch (IOException e) {
e.printStackTrace();
}
return estabelecimentoList;
}
Look at this awesome new library which is available via gradle :)
build.gradle: compile 'com.apptakk.http_request:http-request:0.1.2'
Usage:
new HttpRequestTask(
new HttpRequest("http://httpbin.org/post", HttpRequest.POST, "{ \"some\": \"data\" }"),
new HttpRequest.Handler() {
#Override
public void response(HttpResponse response) {
if (response.code == 200) {
Log.d(this.getClass().toString(), "Request successful!");
} else {
Log.e(this.getClass().toString(), "Request unsuccessful: " + response);
}
}
}).execute();
https://github.com/erf/http-request
This is the new code for HTTP Get/POST request in android. HTTPClient is depricated and may not be available as it was in my case.
Firstly add the two dependencies in build.gradle:
compile 'org.apache.httpcomponents:httpcore:4.4.1'
compile 'org.apache.httpcomponents:httpclient:4.5'
Then write this code in ASyncTask in doBackground method.
URL url = new URL("http://localhost:8080/web/get?key=value");
HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection();
urlConnection.setRequestMethod("GET");
int statusCode = urlConnection.getResponseCode();
if (statusCode == 200) {
InputStream it = new BufferedInputStream(urlConnection.getInputStream());
InputStreamReader read = new InputStreamReader(it);
BufferedReader buff = new BufferedReader(read);
StringBuilder dta = new StringBuilder();
String chunks ;
while((chunks = buff.readLine()) != null)
{
dta.append(chunks);
}
}
else
{
//Handle else
}
For me, the easiest way is using library called Retrofit2
We just need to create an Interface that contain our request method, parameters, and also we can make custom header for each request :
public interface MyService {
#GET("users/{user}/repos")
Call<List<Repo>> listRepos(#Path("user") String user);
#GET("user")
Call<UserDetails> getUserDetails(#Header("Authorization") String credentials);
#POST("users/new")
Call<User> createUser(#Body User user);
#FormUrlEncoded
#POST("user/edit")
Call<User> updateUser(#Field("first_name") String first,
#Field("last_name") String last);
#Multipart
#PUT("user/photo")
Call<User> updateUser(#Part("photo") RequestBody photo,
#Part("description") RequestBody description);
#Headers({
"Accept: application/vnd.github.v3.full+json",
"User-Agent: Retrofit-Sample-App"
})
#GET("users/{username}")
Call<User> getUser(#Path("username") String username);
}
And the best is, we can do it asynchronously easily using enqueue method

get request is not working on android device however it's working on my pc

I've wrote this simple get request
OkHttpClient httpClient = new OkHttpClient();
StringBuilder url = new StringBuilder(serverURL);
String result = "init";
if(params!=null && params.size()!=0){
url = url.append("?"+prepareParam(params));
}
Request request = new Request.Builder().url(url.toString()).build();
Response response = null;
try {
response = httpClient.newCall(request).execute();
result = response.body().string();
} catch (IOException e) {
e.printStackTrace();
}
catch (Exception e){
e.printStackTrace();
}finally {
response.close();
}
when i tested it on my pc it worked just fine however when i tested it on my mobile it gave me the following exception
java.lang.NullPointerException: Attempt to invoke virtual method 'void okhttp3.Response.close()' on a null object reference
try{
response.close();
}
catch(NullPointerException e){
e.printStackTrace();
}
inside finally block.
Try this out rather then using this many try catch.
OkHttpClient client = new OkHttpClient();
String doGetRequest(String url) throws IOException {
Request request = new Request.Builder()
.url(url)
.build();
Response response = client.newCall(request).execute();
return response.body().string();
}
Then just call above method and pass your url whenever you need.
String response =doGetRequest(yourUrl);

Populating text fields on a website from android without showing a WebView

Is there a way to put values into text fields on a webpage from android without loading/showing a WebView? For example, I have two strings and would like to populate two fields on a webpage, is there a way to do this "in the background" or in other words, not having to open a window that the user sees?
Thanks
Update
Found a solution with the help of Tango
This is in my OkHttpHandler class:
public class OkHttpHandler extends AsyncTask<String, Void, String> {
OkHttpClient client = new OkHttpClient();
String cardNumber, privNumber;
public OkHttpHandler(String cardNumber, String privNumber) {
this.cardNumber = cardNumber;
this.privNumber = privNumber;
}
#Override
protected String doInBackground(String... strings) {
RequestBody formBody = new FormBody.Builder()
//Change .add first parameter to the text field you want to populate
.add("CardNbr", cardNumber)
.add("CardPin", privNumber).build();
Request request = new Request.Builder().url(strings[0])
.post(formBody).build();
try {
Response response = client.newCall(request).execute();
if (!response.isSuccessful())
throw new IOException("Unexpected code "+ request.toString());
return response.body().string();
} catch (Exception e) {
}
return null;
}
}
A snippet of my MainActivity Class and I print the response to the Log
OkHttpHandler handler = new OkHttpHandler(items.get(0).getNumber(), items.get(0).getPrivNumber());
String result = "";
try {
result = handler.execute("urlHere.com").get();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
Log.d("returned value", result);
Using OkHttp
final OkHttpClient client = new OkHttpClient();
RequestBody formBody = new FormBody.Builder()
.add("field to be filled", "content")
.build();
Request request = new Request.Builder()
.url("webpage url")
.post(formBody)
.build();
Response response = client.newCall(request).execute();
if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

Can't seem to get http get parameters sent from my Android app to display on my PHP page

I can't seem to get my PHP page to display the data I have sent using a http client in Android. All I need now is displaying it in PHP which seems to be a challenge, I know I have done something wrong.
Any guidance would be much appreciated. I have tried everything from var_dump($_SERVER) to json_decode to display it in PHP. Is it even possible to display it on a PHP page?
private class Connection extends AsyncTask{
#Override
protected Object doInBackground(Object[] objects){
try{
PostData(R.id.fullscreen_content, 3);
}
catch(IOException exception){
exception.printStackTrace();
}
return null;
}
}
protected void PostData(Integer Question_ID,Integer ResponseChosen_ID) {
URL url = new URL("http://10.0.2.2:443/SwlLogin.php");
HttpURLConnection conn =(HttpURLConnection)url.openConnection();
conn.setDoOutput(true);
HttpClient httpClient = new DefaultHttpClient();
HttpGet post = new HttpGet(conn.getURL().toString());
post.setHeader("Content-type","application/json");
conn.connect();
Date date = new Date();
SimpleDateFormat dt = new SimpleDateFormat("yyyy-MM-dd", Locale.UK);
SimpleDateFormat time = new SimpleDateFormat("HH:mm:ss",Locale.UK);
String nowDate = dt.format(date);
String nowTime = time.format(date);
String phpDate = nowDate;
String phpTime = nowTime;
ArrayList<NameValuePair> params = new ArrayList<>();
params.add(new BasicNameValuePair("Question ID", Question_ID.toString()));
params.add(new BasicNameValuePair("Response_Chosen_ID", ResponseChosen_ID.toString()));
params.add(new BasicNameValuePair("TimestampDate", phpDate));
params.add(new BasicNameValuePair("time", phpTime));
JSONArray array = new JSONArray();
array.put(params);
post.setHeader("postData", params.toString());
post.getParams().setParameter("JSON", params);
HttpParams var = httpClient.getParams();
var.setParameter("GET",params);
HttpResponse response = httpClient.execute(post);
OutputStreamWriter write = new OutputStreamWriter(conn.getOutputStream());
BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
StringBuilder builder = new StringBuilder();
String line = null;
while((line = reader.readLine()) != null){
builder.append(line);
}
Log.d("Response:", builder.toString());
builder.toString();
reader.close();
public void happy_click(View view) throws IOException {
try{
new Connection().execute();
report_success();
}
catch(Exception exception){
messageBox("Response was not successful","Failed to process response" + exception.getMessage());
}
}
you can not run this code on the UI thread or you will get a NetworkRequestOnUIThread exception. you have to do this on a different thread.
try using AsyncTask via
private class Uploader extends AsyncTask<Void,Void,Void>{
protected void doInBackground(){
// do network request here
}
private void onPostExecute(){
// handle UI updates here as is on ui Thread
}
}
or you could look at using OkHTTP library which I recommend highly. to do this download the jar from okHttp. add it to you libs folder then you can do network call like this
MediaType JSON = MediaType.parse("application/json; charset=utf-8");
JSONObject parcel = new JSONObject();
try{
parcel.put("email", emailEdit.getText().toString());
parcel.put("password", passwordEdit.getText().toString());
parcel.put("device", "Android");
parcel.put("hash", "1234");;
}catch (JSONException e ){
e.printStackTrace();
}
RequestBody body = RequestBody.create(JSON, parcel.toString());
Request request = new Request.Builder()
.header("Content-Type", "application/json")
.url("YOURURL")
.post(body)
.build();
client.newCall(request).enqueue(new Callback() {
#Override
public void onFailure(Call call, IOException e) {
if (null != e) {e.printStackTrace();}
}
#Override
public void onResponse(Call call, Response response) throws IOException {
if (null != response && response.message().equals(Constants.KEY_OK)) {
JSONObject serverResponse;
try{
serverResponse = new JSONObject(response.body().string());
if(serverResponse.getBoolean(Constants.KEY_SUCCESS)){
Constants.getInstance().setToken(serverResponse.getString(Constants.KEY_TOKEN));
moveToHomePage();
}else{
showLoginFail();
}
}catch (JSONException e ){
e.printStackTrace();
}
response.body().close();
} else {
showLoginFail();
}
}
});
also make sure you have
<uses-permission android:name="...permision.INTERNET">
in your manifest file

Android: send post that has no response

In my app, I need to send all sorts of POST requests to a server. some of those requests have responses and others don't.
this is the code I'm using to send the requests:
private static final String TAG = "Server";
private static final String PATH = "http://10.0.0.2:8001/data_connection";
private static HttpResponse response = null;
private static StringEntity se = null;
private static HttpClient client;
private static HttpPost post = null;
public static String actionKey = null;
public static JSONObject sendRequest(JSONObject req) {
try {
client = new DefaultHttpClient();
actionKey = req.getString("actionKey");
se = new StringEntity(req.toString());
se.setContentEncoding(new BasicHeader(HTTP.CONTENT_ENCODING, "application/json"));
se.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
post = new HttpPost(PATH);
post.setEntity(se);
Log.d(TAG, "http request is being sent");
response = client.execute(post);
Log.d(TAG, "http request was sent");
if (response != null) {
InputStream in = response.getEntity().getContent();
String a = convertFromInputStream(in);
in.close();
return new JSONObject(a);
}
} catch (UnsupportedEncodingException e) {
Log.d(TAG, "encoding request to String entity faild!");
e.printStackTrace();
} catch (ClientProtocolException e) {
Log.d(TAG, "executing the http POST didn't work");
e.printStackTrace();
} catch (IOException e) {
Log.d(TAG, "executing the http POST didn't work");
e.printStackTrace();
} catch (JSONException e) {
Log.d(TAG, "no ActionKey");
e.printStackTrace();
}
return null;
}
private static String convertFromInputStream(InputStream in)
throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(in));
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = br.readLine()) != null) {
sb.append(line);
}
return (sb.toString());
}
This is the code for the AsyncTask class that sends the request:
class ServerRequest extends AsyncTask<JSONObject, Void, JSONObject> {
#Override
protected JSONObject doInBackground(JSONObject... params) {
JSONObject req = params[0];
JSONObject response = Server.sendRequest(req);
return response;
}
#Override
protected void onPostExecute(JSONObject result) {
// HANDLE RESULT
super.onPostExecute(result);
}
}
my problem starts when the server doesn't return a response. the AsyncTask thread stays open even after the work is done because the HTTPClient never closes the connection.
Is there a way to not wait for a response? this is something that will definitely add a lot of overhead to the server since all the Android apps trying to connect to it will keep the connection alive, and will probably cause many problems on the app itself.
Basically, what I'm looking for is a method that will allow me to send to POST message and kill the connection right after the sending of the request since there is no response coming my way.
Just, Set ConnectionTimeOut with HttpClient Object, (Code is for your understanding in your case it may be different)
int TIMEOUT_MILLISEC = 30000;
HttpParams httpParams = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpParams, TIMEOUT_MILLISEC);
HttpConnectionParams.setSoTimeout(httpParams, TIMEOUT_MILLISEC);
HttpClient httpclient = new DefaultHttpClient(httpParams);
HttpPost httppost = new HttpPost(url);
httppost.addHeader("Content-Type", "application/json");
Now, It will terminate the Connection after TimeoOut you defined. But be sure this will throw TimeOutException so You have to handle this exception in your HttpRequest.. (Use Try -catch)
EDIT: Or you can use HttpRequestExecutor class.
From class HttpRequestExecutor of package org.apache.http.protocol
protected boolean canResponseHaveBody (HttpRequest request, HttpResponse response)
Decide whether a response comes with an entity. The implementation in this class is based on RFC 2616. Unknown methods and response codes are supposed to indicate responses with an entity.
Derived executors can override this method to handle methods and response codes not specified in RFC 2616.

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