在java中使用有效负载发送post请求

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

URL url = new URL("目标URL");

HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/json");
connection.setDoOutput(true);

String payload = "{\"key1\":\"value1\", \"key2\":\"value2\"}";

OutputStream outputStream = connection.getOutputStream();
outputStream.write(payload.getBytes());
outputStream.flush();
outputStream.close();

int responseCode = connection.getResponseCode();
BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
StringBuilder response = new StringBuilder();
while ((line = reader.readLine()) != null) {
    response.append(line);
}
reader.close();

System.out.println("Response Code: " + responseCode);
System.out.println("Response Body: " + response.toString());