如何通过Java swing GUI发出Post请求

Question

I have made a GUI in Java Swing and want to hit an API (POST method) On a button click like

http://www.myapi.domain/v1

I have to send a JSON object as a request parameter along with the header ie (Headers["custom-Header"] == "AXYZ") I have converted my Strings to a JSON object like

{"machineKey":"","serialNumber":"","name":"","mobile":"","productKey":"","email":""}

What I simply did is

public void actionPerformed(ActionEvent e) 
 {
    if (e.getSource() == Submit)
     {

        dispose();
        new Otp().setVisible(true);
     }
      else
   {
        name.setText("");
        email.setText("");
        mobile.setText("");
        machineKey.setText("");
        productKey.setText("");
        serialNumber.setText("");
    }
  String Sname=   name.getText();
  String Semail=  email.getText();
  String Smobile=   mobile.getText();
  String SmachineKey=  machineKey.getText();
  String SproductKey=  productKey.getText();
  String SserialNumber=  serialNumber.getText();    

    JSONObject abc=prepareReqJsonObj(Sname,Semail,Smobile,SmachineKey,SproductKey,SserialNumber);
    System.out.println(abc);

 }

Now, how can I make request directly from my GUI button to Hit the API, what way I can achieve this and get a response.

Thanks for your help in advance :)

Answer 1

Have a look at this example on how to use HttpClient to POST your data.

Basically you create an HttpClient, create a POST request, fill that request with your data and then submit it.

Answer 2

Added this as a generic Utility class for all post requests

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class Utility {

public static String excutePost(String targetURL, String urlParameters)
  {
    URL url;
    HttpURLConnection connection = null;  
    try {
      //Create connection
      url = new URL(targetURL);
      connection = (HttpURLConnection)url.openConnection();
      connection.setRequestMethod("POST");
      connection.setRequestProperty("Content-Type", 
           "application/json");
      connection.setRequestProperty("custom-Header", "XYZ");

      connection.setRequestProperty("Content-Length", "" + 
               Integer.toString(urlParameters.getBytes().length));
      connection.setRequestProperty("Content-Language", "en-US");  

      connection.setUseCaches (false);
      connection.setDoInput(true);
      connection.setDoOutput(true);


      //Send request
      DataOutputStream wr = new DataOutputStream (
                  connection.getOutputStream ());
      wr.writeBytes (urlParameters);
      wr.flush ();
      wr.close ();

      //Get Response    
      InputStream is = connection.getInputStream();
      BufferedReader rd = new BufferedReader(new InputStreamReader(is));
      String line;
      StringBuffer response = new StringBuffer(); 
      while((line = rd.readLine()) != null) {
        response.append(line);
        response.append('\r');
      }
      rd.close();
      return response.toString();

    } catch (Exception e) {

      e.printStackTrace();
      return null;

    } finally {

      if(connection != null) {
        connection.disconnect(); 
      }
    }
  }
 }

and this one in Action listener ->

 String Sname=   name.getText();
  String Semail=  emailid.getText();
  String Smobile=   mobile.getText();
  String SmachineKey=  machineKey.getText();
  String SproductKey=  productkey.getText();
  String SserialNumber=  serialNo.getText();    

    JSONObject reqObj=prepareReqJsonObj(Sname,Semail,Smobile,SmachineKey,SproductKey,SserialNumber);

    String reqString= reqObj.toString();
    String APIUrl=  "http://example.com/v1/api";

   String response=  Utility.excutePost(APIUrl, reqString);

   System.out.println(reqObj);
   System.out.println(reqString);
   System.out.println(response);

 }

@SuppressWarnings("unchecked")
public JSONObject prepareReqJsonObj(String s1,String s2,String s3,String s4,String s5,String s6){
 JSONObject jsonobj = new JSONObject();



    jsonobj.put("name", s1);
    jsonobj.put("emailid", s2);
    jsonobj.put("mobile",s3 );
    jsonobj.put("machineKey",s4 );
    jsonobj.put("productkey", s5);
    jsonobj.put("serialNo", s6);

    return jsonobj;