如何设置Content-Type :application/json？

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

import requests

headers = {
    "Content-Type": "application/json"
}
response = requests.post(url, headers=headers)

connection.setRequestMethod("POST");
connection.setDoOutput(true);
String jsonInputString = "{\"key1\": \"value1\", \"key2\": \"value2\"}";
OutputStream outputStream = connection.getOutputStream();
outputStream.write(jsonInputString.getBytes());
outputStream.flush();
outputStream.close();

import json

data = {
    "key1": "value1",
    "key2": "value2"
}
json_data = json.dumps(data)
response = requests.post(url, headers=headers, data=json_data)