Converting byte[] to JsonObject

import java.nio.charset.StandardCharsets;
import org.apache.commons.io.IOUtils;

JSONObject jsonObject = new JSONObject(IOUtils.toString(responseBody, StandardCharsets.UTF_8));

Try this :

String testV=new JSONObject(new String(responseBody)).toString();

or this if you need a JSONObject

JSONObject testV=new JSONObject(new String(responseBody));

The issue is that you declare a String variable and intent to store a JSONObjectinto it.