How to fetch token from Token API using Java

Question

I am trying to fetch token by calling token API but unable to fetch the same. It is working in postman. Postman details are as follows

My code

import java.io.*;
import java.net.*;
public class GetToken {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        String accessToken = "";
        String tokenURL="https://test.iapsoftware.com/iap6/MobileServices/token";
        String grantType = "password";
        String userName="APITester";
        String password="password"; 
        String ClientCode ="iaptest1";
        String ClientInterface ="API";
        
                try {
                     URL url = new URL(tokenURL);
                    HttpURLConnection httpConn = (HttpURLConnection)url.openConnection();
                    // Set header
                    httpConn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
                    httpConn.setRequestProperty("ClientCode", ClientCode);
                    httpConn.setRequestProperty("ClientInterface", ClientInterface);
                    
                    //httpConn.setRequestBody();
                    httpConn.setDoOutput(true);
                    httpConn.setDoInput(true);
                    httpConn.setRequestMethod("POST"); 
                    //Set Request Body
                    String jsonInputString =("grant_type="+grantType+",username="+userName+",password="+password);
                            
                    OutputStream os = httpConn.getOutputStream();
                    byte[] input = jsonInputString.getBytes("utf-8");
                    os.write(input, 0, input.length);            
                     // Read the response.
                    InputStreamReader isr=null;
                        if (httpConn.getResponseCode() == 200) {
                     isr = new InputStreamReader(httpConn.getInputStream());
                    }
                            else
                         {
                                               isr = new InputStreamReader(httpConn.getErrorStream());
                   }
                    BufferedReader in = new BufferedReader(isr);
                    String responseString = "";
                    String outputString = "";
                   // Write response to a String.
                    while ((responseString = in.readLine()) != null) {
                     outputString = outputString + responseString;
                    }
                       accessToken = outputString;
                } 
                catch (Exception e) 
                {
                    accessToken = "Error"; //+ e.getMessage();            
                }

                System.out.println(accessToken);
        
    }

}

error

-As per my understanding I am not passing correct input. Input needs to be URL encoded and I am sending it as JSON. Kindly suggest and provide solution for the same.

Answer 1

After setting up the body correctly it worked

String urlParameters  = ("grant_type="+grantType+"&username="+userName+"&password="+password);
                                            
OutputStream os = httpConn.getOutputStream();
                    
byte[] postData = urlParameters.getBytes("utf-8");
int postDataLength = postData.length;
                    
os.write(postData, 0, postDataLength);