get response body

app/src/main/java/asgardius/page/r3forumtest/MainScreen.java

@@ -4,15 +4,90 @@ import androidx.appcompat.app.AppCompatActivity;
 
 import android.content.Intent;
 import android.os.Bundle;
+import android.widget.Toast;
+
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.net.URL;
+
+import javax.net.ssl.HttpsURLConnection;
 
 public class MainScreen extends AppCompatActivity {
     String username;
+    HttpsURLConnection myConnection;
+    String myData;
+    URL endpoint;
+    boolean success;
+    BufferedReader br;
+    StringBuilder sb;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main_screen);
         username = getIntent().getStringExtra("username");
+        Thread login = new Thread(new Runnable() {
+
+            @Override
+            public void run() {
+                try  {
+                    //Your code goes here
+                    endpoint = new URL("https://desktop.asgardius.company/test/restful/items/read.php");
+                    myConnection = (HttpsURLConnection) endpoint.openConnection();
+                    myConnection.setRequestProperty("User-Agent", "r3-forum-test");
+                    myConnection.setRequestMethod("POST");
+                    // Create the data
+                    myData = "{\n" +
+                            "\"id\": \""+username+"\"\n" +
+                            "}";
+                    // Enable writing
+                    myConnection.setDoOutput(true);
+                    // Write the data
+                    myConnection.getOutputStream().write(myData.getBytes());
+                    System.out.println(myConnection.getResponseCode());
+                    if (myConnection.getResponseCode() == 200) {
+                        success = true;
+                        br = new BufferedReader(new InputStreamReader((myConnection.getInputStream())));
+                        sb = new StringBuilder();
+                        String output;
+                        while ((output = br.readLine()) != null) {
+                            sb.append(output);
+                        }
+                        System.out.println(sb.toString());
+                    } else {
+                        success = false;
+                    }
+
+                    runOnUiThread(new Runnable() {
+
+                        @Override
+                        public void run() {
+                            //Test
+                            if (success) {
+                                Toast.makeText(getApplicationContext(), "Credenciales correctas", Toast.LENGTH_SHORT).show();
+
+                            } else {
+                                Toast.makeText(getApplicationContext(), "Credenciales incorrectas", Toast.LENGTH_SHORT).show();
+                            }
+                        }
+                    });
+
+                } catch (Exception e) {
+                    e.printStackTrace();
+                    runOnUiThread(new Runnable() {
+
+                        @Override
+                        public void run() {
+                            Toast.makeText(getApplicationContext(), "Conexión fallida", Toast.LENGTH_SHORT).show();
+                        }
+                    });
+                    //Toast.makeText(getApplicationContext(),getResources().getString(R.string.media_list_fail), Toast.LENGTH_SHORT).show();
+                    //finish();
+                }
+            }
+        });
+
+        login.start();
     }
 
     public void onBackPressed(){