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Java HTTP POST request code equivalent to curl call

curl -X POST --header "Content-Type: text/plain" --header "Accept: application/json" -d "HELLO THERE" "http://localhost:8080/rest/items/Echo_Living_Room_TTS"
I want to write Java code that does the same thing as this curl invocation. Here's what I've written so far:
URL myurl =new URL("http://localhost:8080/rest/items/Echo_Living_Room_TTS");
HttpURLConnection connection = (HttpURLConnection) myurl.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
connection.setRequestProperty("Content-Type","text/plain");
connection.connect();
String urlParameters = "HELLO THERE";
byte[] postData = urlParameters.getBytes( StandardCharsets.UTF_8 );
if(something happens) {
try( DataOutputStream wr = new DataOutputStream( connection.getOutputStream())) {
wr.write( postData );
}
}
connection.disconnect();
Have I done it right? Are there any mistakes or omissions?

Ok seems like I made it works:
URL myurl =new URL("http://localhost:8080/rest/items/Echo_Living_Room_TTS");
HttpURLConnection connection = (HttpURLConnection) myurl.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
connection.setRequestProperty("Content-Type","text/plain");
connection.setRequestProperty("Accept","application/json");
String mystring = "whatever";
byte[] postData = mystring.getBytes( StandardCharsets.UTF_8 );
int lenght = postData.length;
connection.setFixedLengthStreamingMode(lenght);
connection.connect();
try(OutputStream os = connection.getOutputStream()) {
os.write( postData );
}
connection.disconnect();
thank you all

Pass json object by navigator instead of java

I have a java application with this code :
URL url = new URL("http://myurl/");
HttURLConnection connection = (HttURLConnection) url.openConnection();
connection.setDoInput(true);
connection.setDoOutplut(true);
connection.setRequestProperty("Content-Type", "application/json");
BufferedWriter buffer = new BufferedWriter(new OutputStreamWriter(connection.getOutputStream()));
buffer.write("{\"foo:\"0}");
buffer.flush();
I just want to do the samething in my navigatour URL bar.
Edit
I found a tool to modifier headers. Here a screenshoot of the dev tool when I load my page.
Now where did I put my Json object?

If you need to send JSON data to your URL your code should be like this,
URL url = new URL("http://myurl/");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setDoOutput(true);
con.setRequestMethod("POST");
con.setRequestProperty("Content-Type", "application/json");
String input = "{\"foo\":\"bar\"}";
OutputStream ous = con.getOutputStream();
ous.write(input.getBytes());
ous.flush();
if (con.getResponseCode() != HttpURLConnection.HTTP_OK)
{
throw new RuntimeException("Failed : HTTP error code : " + con.getResponseCode());
}else
{
BufferedReader br = new BufferedReader(new InputStreamReader((con.getInputStream())));
String output;
System.out.println("Output from Server .... \n");
while ((output = br.readLine()) != null)
{
System.out.println(output);
}
}
con.disconnect();
If you need GET Method then you can place this,
con.setRequestMethod("GET");
con.setRequestProperty("Accept", "application/json");
If you need to send Request Body with the URL you can use CURL. And also you can use POSTMAN. By using this you can send requests and receive the response.
CURL will be like this,
curl -v -H "Content-Type: application/json" -X POST \
-d '{\"foo\":\"bar\"}' http://myurl/
You can use Firefox to perform what you need, Read the 2nd answer.

JSON POST Data via HttpURLConnection

I am trying to make a request to my RESTful API using Android and HttpURLConnection. The data must be sent in the JSON format via POST data.
Here is my code:
JSONObject check_request = new JSONObject();
check_request.put("username", username);
JSONObject request = BuildRequest(check_request, "username_check", false);
Log.i("DEBUG", request.toString());
// DEBUG OUTPUT: {"timestamp":1526900318,"request":{"username":"blubberfucken","type":"username_check"}}
URL request_url = new URL(apiURL);
HttpURLConnection connection = (HttpURLConnection)request_url.openConnection();
connection.setRequestProperty("User-Agent", "TheGameApp");
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-type", "application/json; charset=UTF-8");
connection.setDoOutput(true);
connection.setDoInput(true);
OutputStream os = connection.getOutputStream();
os.write(request.toString().getBytes("UTF-8"));
os.flush();
InputStream in = new BufferedInputStream(connection.getInputStream());
String result = "";
BufferedReader br = new BufferedReader(new InputStreamReader(in, "UTF8"));
String str;
while ((str = br.readLine()) != null)
{
result += str;
}
Log.i("DEBUG", result);
//JSONObject result_json = new JSONObject(result);
os.close();
in.close();
connection.disconnect();
You can see the Debug output as a Comment. The Problem is that the API does not receive any POST data. I have used PHPs var_dump to dump $_POST and $_REQUEST which both are empty arrays.
What am I missing here?
As the question popped up if the API work. This cURL command works fine with the correct result (it is the same JSON data as the debugger printed):
curl -d '{"timestamp":1526900318,"request":{"username":"blubberfucken","type":"username_check"}}' -H "Content-Type: application/json" -X POST http://localhost/v1/api.php

Just for the sake of completeness: The example above is working. The solution to the problem was pa part in PHP on the server side, where I checked the content type and used strpos to search for application/json in $_SERVER['CONTENT-TYPE'] and switched the needle and haystack (thus searching for application/json; charset=UTF8 in the string application/json instead of the other way around).

How to make same cURL request in android java?

I cannot understand request below for cURL:
curl -X POST -u "client_id:secret" \
https://bitbucket.org/site/oauth2/access_token -d grant_type=password \
-d username={username} -d password={password}
How can I make same request in java (Android)?
Now, I try so:
String auth = vcs.getKey() + ":" + vcs.getSecret();
byte[] authEncBytes = Base64.encode(auth.getBytes(), Base64.DEFAULT);
String authStringEnc = new String(authEncBytes);
URL url = new URL("https://bitbucket.org/site/oauth2/access_token");
HttpsURLConnection connection = (HttpsURLConnection)url.openConnection();
connection.setRequestProperty("Authorization", "Basic " + authStringEnc);
connection.setRequestMethod("POST");
connection.setRequestProperty("grant_type", "password");
connection.setRequestProperty("username", mLogin);
connection.setRequestProperty("password", mPassword);
But it doesn't work.

You are passing the post parameters with at request header. Remove the last three and replace with below:
String params = "grant_type=password&username=xyz&password="+ java.net.URLEncoder.encode("urp&^!ass", "UTF-8");
OutputStream os = connection.getOutputStream();
BufferedWriter writer = new BufferedWriter( new OutputStreamWriter(os, "UTF-8"));
writer.write(params);
writer.flush();
writer.close();
os.close();
int responseCode = connection.getResponseCode();

Java cURL alternative with HttpURLConnection

I was asked to port a PHP module I was writing to Java. I was previously using PHP's native cURL library, now trying to achieve the same action with HttpURLConnection.
Here's the call I want to do with cURL:
curl -u 'ExactID:Password' \
-H 'Content-Type: application/json; charset=UTF-8' \
-H 'Accept: application/json' \
-d '{
"transaction_type":"00",
"amount":"15.75",
"cardholder_name":"PaulTest",
"transarmor_token":"3000",
"credit_card_type":"Visa",
"cc_expiry":"0016",
}' \
https://api.demo.globalgatewaye4.firstdata.com/transaction/v11
Here's what I have in Java, which returns a HTTP 400 error. Any ideas?
public static void main(String[] args) {
URL url = new URL("https://api.demo.globalgatewaye4.firstdata.com/transaction/v11");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setDoInput(true);
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
conn.setRequestProperty("Accept", "application/json");
String userpass = "ExactID" + ":" + "Password";
String basicAuth = "Basic " + new String(new Base64().encode(userpass.getBytes()));
conn.setRequestProperty ("Authorization", basicAuth);
JSONObject obj = new JSONObject();
obj.put("transaction_type", "00");
obj.put("amount", "10");
obj.put("cardholder_name", "PaulTest");
obj.put("transarmor_token", "3000");
obj.put("cc_expiry", "0016");
obj.put("credit_card_type", "Visa");
String input = obj.toString();
System.out.println(input);
OutputStream os = conn.getOutputStream();
os.write(input.getBytes());
os.flush();
if (conn.getResponseCode() != HttpURLConnection.HTTP_CREATED) {
throw new RuntimeException("Failed : HTTP error code : "+ conn.getResponseCode() + conn.getResponseMessage());
}

One ambiguity in your java code is on string to byte array encoding. By default java will use your default platform encoding, but it's a good practice to express it explicitly because it often lead to hard to track bug
String basicAuth = "Basic " + new String(new Base64().encode(userpass.getBytes("ISO-8859-1")));
To be sure also check the encoded base 64 value generated by java on curl by using
-H 'Authorization: Basic ....`
Instead of -u
Also I'd try to cast the created URLConnection to HttpsURLConnection. Thay may/not make difference
HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();

After tinkering around, I made two mistakes:
For this POST method, basic authentication was not required. The user & pw goes into the JSON body along with the other parameters.
Also, my "transarmor_token" field needed to be 16 digits.
Conclusion: HttpURLConnection is a great cURL alternative. Forget about using the curl-java binding.
Thanks!