Develop Reference

Switch to POST method in java doesn't work

I can't understand how to switch to POST method in my HttpsURLConnection. On the debugger the request method is GET also after the setRequestMethod method. Can you tell me where is my mistake?
try {
URL url=new URL("https://smartmates.herokuapp.com");
HttpsURLConnection connection= (HttpsURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setDoInput(true);
connection.setDoOutput(true);
//I'll add some params here
connection.disconnect();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
Thank you very much.

This is a piece of code that I use to POST the String mensaje and receiving rta.ToString(). I think that DoSetInput(true) is a mistake, because you want to send a POST (output) and, eventually, get a response.
`
String urlParametros = "<?xml version=\"1.0\"?>";
urlParametros = urlParametros + mensaje;
byte[] postDatos = urlParametros.getBytes(StandardCharsets.UTF_8);
try {
URL miurl = new URL(url);
con = (HttpURLConnection) miurl.openConnection();
con.setDoOutput(true);
con.setRequestMethod("POST");
//******…………..
con.setRequestProperty("User-Agent", "Java client");
con.setRequestProperty("Content-Type", "text/xml");
try (DataOutputStream datos = new DataOutputStream(con.getOutputStream())) {
datos.write(postDatos);
}
StringBuilder rta;
try (BufferedReader entrada = new BufferedReader(
new InputStreamReader(con.getInputStream()))) {
String linea;
rta = new StringBuilder();
while ((linea = entrada.readLine()) != null) {
rta.append(linea);
rta.append(System.lineSeparator());
}
}
return rta.toString();
} finally {
con.disconnect();
}´
Hope it helps
Daniel

HttpURLConnection Post issues

I have the following code in my program, used for inserting record -
private Void downloadUrl() throws IOException {
String postParameters;
HttpURLConnection urlConnection = null;
postParameters = "name="+ URLEncoder.encode(user.name,"UTF-8")
+"&age="+URLEncoder.encode(user.age+"","UTF-8")
+"&username="+URLEncoder.encode(user.username,"UTF-8")
+"&password="+URLEncoder.encode(user.password,"UTF-8");
if (postParameters != null) {
Log.i("Post", "POST parameters: " + postParameters);
try {
URL urlToRequest = new URL(SERVER_ADDRESS);
urlConnection = (HttpURLConnection) urlToRequest.openConnection();
urlConnection.setReadTimeout(30000 /* milliseconds */);
urlConnection.setConnectTimeout(30000 /* milliseconds */);
urlConnection.setDoOutput(true);
urlConnection.setRequestMethod("POST");
urlConnection.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded");
urlConnection.setFixedLengthStreamingMode(
postParameters.getBytes().length);
PrintWriter out = new PrintWriter(urlConnection.getOutputStream());
out.print(postParameters.getBytes());
out.close();
// handle issues
int statusCode = urlConnection.getResponseCode();
Log.e("Response", "The response is: " + statusCode);
} catch (MalformedURLException e) {
// handle invalid URL
Log.e("Response", "invalid URL");
} catch (SocketTimeoutException e) {
// hadle timeout
Log.e("Response", "handle timeout");
} catch (IOException e) {
// handle I/0
Log.e("Response", "handle IO problem");
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
}
}
return null;
}
The code is showing no errors and the logged entries are
09-27 12:24:17.944 5006-5039/? E/Response﹕ The response is: 200
09-27 12:24:33.729 5006-5118/? I/Post﹕ POST parameters: name=vibha&age=25&username=vib&password=1234
But when I check the database, the new record is not created.
But if I use PHP code in a file and post the same parameters,the records are getting inserted.
My requirement for help and guidance is how to pass the post parameter in the HttpURLConnection class

POST Android json data

I'm trying to POST some data to my server, but I don't know why, I always get 400 messages from it.
I want to send this POST structure:
POST /api/v0.1/observations/3 HTTP/1.1
Host: 54.154.117.132`
Content-Type: application/json
Cache-Control: no-cache
{
"data" :
{
"field1" : 1111111
},
"timestamp": "2015-05-13T12:23:42.648738"
}
If I send that with curl, or wget, I get a 200 Http status.
I'm doing this on android:
public void POST(String json) throws MalformedURLException {
int httpResult;
//URL url = new URL(getString(R.string.URL));
URL url = new URL(getString(R.string.URL_test2));
HttpURLConnection con;
JSONObject obj1 = new JSONObject();
JSONObject obj2 = new JSONObject();
try {
obj1.put("field1",222);
obj2.put("data", obj1);
obj2.put("timestamp", "2015-06-8T12:05:42.648738");
} catch (JSONException e) {
e.printStackTrace();
}
try {
con = (HttpURLConnection) url.openConnection();
con.setDoOutput(true);
con.setRequestMethod("POST");
con.setUseCaches(false);
con.setConnectTimeout(10000);
con.setReadTimeout(10000);
con.setRequestProperty("Content-Type","application/json");
con.setRequestProperty("Host", "54.154.117.132");
con.connect();
OutputStreamWriter out = new OutputStreamWriter(con.getOutputStream());
out.write(obj2.toString());
out.close();
httpResult = con.getResponseCode();
Log.i("Request","--> "+httpResult);
if (httpResult == HttpURLConnection.HTTP_OK) Log.i("HTTP"," --> all ok");
else Log.i("HTTP", " --> smthg wrong!");
} catch (IOException e) {
Log.i("ERROR"," !!! Interrupcion a la hora de conectarse");
}
}
I don't know if this is exactly the same structure, that's is my conclusion, because using Postman on chrome, and curl or wget, get 200 status.
Someone can help me?
The URL if you want to try is on POST method on the top.

Add your params in JSONObject like below:
JSONObject jsonObject = new JSONObject();
jsonObject .put("field", 222);
JSONObject mainObject = new JSONObject();
try {
mainObject .put("data",jsonObject);
mainObject .put("timestamp","2015-05-13T12:23:42.648738");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
And change here in code:
OutputStreamWriter out = new OutputStreamWriter(con.getOutputStream());
out.write(mainObject.toString()); //change to mainObject from obj2
out.close();

HttpUrlConnection is freezing my AsyncTask

In the "doInBackground" function of a AsyncTask, I got the following piece of code :
try
{
URL url = new URL(myUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(10000);
conn.setConnectTimeout(15000);
conn.setRequestMethod("POST");
conn.setDoInput(true);
Authenticator.setDefault(new Authenticator(){
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication ("myUsername", "myPassword".toCharArray());
}
});
conn.connect();
int response = conn.getResponseCode();
inputStream = conn.getInputStream();
String content = convertInputStreamToString(inputStream);
return content;
catch (Exception e) {
e.printStackTrace();
return null;
}
When the credentials are ok, everything works fine and the ResponseCode is 200. But if I put the wrong credentials, getResponseCode() makes the AsyncTask wait for an answer indefinitely (timeout won't work). Looking at HttpUrlConnection object tells me that the ResponseCode is -1.
I need to handle every situation, even if the user provides a bad credential. How can I get an usable answer? Should I use another class than HttpUrlConnection?

Are you returning String back from this function and are you handling exceptions? Did you write onPostExecute?
Here is the code that works perfectly for me:
URL url = new URL(strUrl);
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setRequestProperty("Host", "myhost.com");
conn.setRequestProperty("Authorization", "Basic " + Base64.encodeToString(toencode, Base64.DEFAULT));
conn.setRequestProperty("User-Agent", "Mozilla/5.0 (Macintosh; U; PPC; en-US; rv:1.3.1)");
conn.setRequestProperty("Accept-Charset", "UTF-8");
conn.setConnectTimeout (5000) ;
conn.setDoOutput(true);
conn.setDoInput(true);
BufferedInputStream in = new BufferedInputStream(conn.getInputStream());
result = Utilities.readStream(in);
status_code = conn.getResponseCode();
return result;
} catch (MalformedURLException e) {
return e.getMessage();
} catch (ProtocolException e) {
try {
status_code = conn.getResponseCode();
} catch (IOException e1) {
status_code = -1;
}
return e.getMessage();
} catch (IOException e) {
try {
status_code = conn.getResponseCode();
} catch (IOException e1) {
status_code = -1;
}
return e.getMessage();
} catch ( Exception e ) {
try {
status_code = conn.getResponseCode();
} catch (IOException e1) {
status_code = -1;
}
return e.getMessage();
}
finally
{
conn = null;
}

Java http post: values arent added

I try to send post request, but webserver returns that I added no post-values. I spent a lot of time trying to solve this issue, but no result. Here is the code:
public static String post(String url, String postParams)
{
URLConnection connection = null;
try
{
connection = initializeConnection(url);
connection.setDoOutput(true);
((HttpURLConnection) connection).setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "text/xml");
connection.setRequestProperty("Accept", "text/xml");
connection.setUseCaches(false);
connection.setDoInput(true);
DataOutputStream wr = new DataOutputStream(connection.getOutputStream());
wr.write(postParams.getBytes());
wr.flush();
wr.close();
// Get Response
InputStream is = connection.getInputStream();
return inputStreamToString(is);
}
catch (Exception e)
{
e.printStackTrace();
return null;
}
}
protected static HttpURLConnection initializeConnection(String stringUrl)
{
HttpURLConnection connection;
URL url = null;
try
{
url = new URL(stringUrl);
}
catch (MalformedURLException e1)
{
e1.printStackTrace();
}
try
{
connection = (HttpURLConnection) url.openConnection();
connection.setConnectTimeout(5000);
}
catch (Exception e)
{
e.printStackTrace();
return null;
}
return connection;
}
public static String inputStreamToString(InputStream is)
{
BufferedReader r = new BufferedReader(new InputStreamReader(is));
StringBuilder total = new StringBuilder();
String line;
try
{
while ((line = r.readLine()) != null)
{
total.append(line);
}
}
catch (IOException e)
{
e.printStackTrace();
}
return total.toString();
}
I receive a message from webserver where it is told that no post-values are added. As far as I understand from the code, the values are added. I'm stuck.

It turned out that all I had to do was to replace
connection.setRequestProperty("Content-Type", "text/xml");
with
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
So simple and so much time spent to clear it out...
By the way, how could I know that server requires this header? I thought that all the work that is essential to the request would be automatically done by java..
P.S. Installing fiddler helped to solve the issue, thanks for that.

debug the 'postParams' parameter and check what been sent.