安卓如何post一个json并接收返回信息

安卓可以使用HttpURLConnection或者OkHttp库来发送POST请求并接收返回信息。

使用HttpURLConnection：

public void postData(String url, JSONObject jsonObj) {
    try {
        URL endpoint = new URL(url);
        HttpURLConnection connection = (HttpURLConnection) endpoint.openConnection();
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Content-Type", "application/json");
        connection.setDoOutput(true);

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

        int responseCode = connection.getResponseCode();
        if (responseCode == HttpURLConnection.HTTP_OK) {
            InputStream inputStream = connection.getInputStream();
            BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
            String line;
            StringBuilder response = new StringBuilder();
            while ((line = reader.readLine()) != null) {
                response.append(line);
            }
            reader.close();
            String result = response.toString();
            // 处理返回结果
        } else {
            // 处理错误情况
        }
        connection.disconnect();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

使用OkHttp：

public void postData(String url, JSONObject jsonObj) {
    OkHttpClient client = new OkHttpClient();
    RequestBody body = RequestBody.create(MediaType.parse("application/json"), jsonObj.toString());
    Request request = new Request.Builder()
            .url(url)
            .post(body)
            .build();

    try {
        Response response = client.newCall(request).execute();
        if (response.isSuccessful()) {
            String result = response.body().string();
            // 处理返回结果
        } else {
            // 处理错误情况
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}