Java GET HTTP openConnection()没有正确编码JSON输出字符串

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.StandardCharsets;

URL url = new URL("http://example.com/api/endpoint");

HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");

connection.setRequestProperty("Content-Type", "application/json");

int responseCode = connection.getResponseCode();

BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream(), StandardCharsets.UTF_8));
String line;
StringBuilder response = new StringBuilder();
while ((line = reader.readLine()) != null) {
    response.append(line);
}
reader.close();

connection.disconnect();