如何使用HttpURLConnection通过Java中的post发送参数？

Question

I am not able to send through a POST method in java parameters using the HttpURLConnection. I've been trying in a few ways and researched a lot, but no way worked for me. I will leave the code below for you to indicate possible modifications that can be made.

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

public class HttpTeste {

    private final String USER_AGENT = "Mozilla/5.0";

    public void sendPost(String url) throws Exception {

        URL obj = new URL(url);
        HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();

        //add request header
        con.setRequestMethod("POST");
        con.setRequestProperty("User-Agent", USER_AGENT);
        con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");

        String urlParameters = "idRoute=1";

        // Send post request
        con.setDoOutput(true);
        DataOutputStream wr = new DataOutputStream(con.getOutputStream());
        wr.writeBytes(urlParameters);
        wr.flush();
        wr.close();

        int responseCode = con.getResponseCode();
        System.out.println("\nSending 'POST' request to URL : " + url);
        System.out.println("Post parameters : " + urlParameters);
        System.out.println("Response Code : " + responseCode);

        BufferedReader in = new BufferedReader(
                new InputStreamReader(con.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();

        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();

        //print result
        System.out.println(response.toString());

    }
}

As you can see, I tried to send the parameters of my request through urlParameters , but it still did not work. The code runs and does not acknowledge any errors, but it does not return a response that should return. I also tried to send the parameters through String urlParameters = URLEncoder.encode ("idRoute", "UTF-8") + "=" + URLEncoder.encode ("1", "UTF-8"); wr.writeBytes(urlParameters); String urlParameters = URLEncoder.encode ("idRoute", "UTF-8") + "=" + URLEncoder.encode ("1", "UTF-8"); wr.writeBytes(urlParameters); But it also did not work, thank you for the collaboration of all!

Answer 1

Does it have to work with HttpURLConnection? If not and you just want to send a POST request I would recommend to use OkHttp3