I want to send a message to LINE from the program I created on Android Studio.

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

public class Main {
  public static void main(String[]args) {
    HttpSendJSON httpSendJSON = new HttpSendJSON();
    String result = httpSendJSON.callPost();
    System.out.println(result);
  }
}

classHttpSendJSON{
  private String ACCESS_TOKEN = "access token";
  private String UID = "User ID";
  private String MESSAGE = "Messages you want to send";

  public String callPost() {
    HttpURLConnection con=null;
    StringBuffer result = new StringBuffer();

    try{
      URL url = new URL ("https://api.line.me/v2/bot/message/push");
      con=(HttpURLConnection) url.openConnection();

      con.setDoOutput(true);
      con.setRequestMethod("POST");
      con.setRequestProperty("Authorization", "Bearer" + ACCESS_TOKEN);
      con.setRequestProperty("Content-Type", "application/json; charset=utf-8");

      String parameters= 
                "{" +
                String.format("\"to\":\"%s\"",", UID)+ 
                "    \"messages\":[{"+
                "        \"type\":\"text\","+
                 String.format("\"text\":\"%s\"",MESSAGE)+ 
                "    }]" +
                "}";
      System.out.println(parameters);

      OutputStreamWriter out = new OutputStreamWriter(con.getOutputStream());
      out.write(parameters);
      out.flush();
      con.connect();

      final int status = con.getResponseCode();
      if(status==HttpURLConnection.HTTP_OK){
          final InputStream in=con.getInputStream();
          String encoding=con.getContentEncoding();
          if(null==encoding){
              encoding = "UTF-8";
          }
          final InputStreamReader inReader = new InputStreamReader (in, encoding);
          final BufferedReader buffReader = new BufferedReader (inReader);
          String line = null;

          while((line=bufReader.readLine())!=null){
              result.append(line);
          }
          bufReader.close();
          inReader.close();
          in.close();
      } else{
          System.out.println(status);
      }
    } catch(Exception e1){
      e1.printStackTrace();
    } US>finally
      if(con!=null){
        con.disconnect();
      }
    }
    return result.toString();
  }
}