无法在Java HTTP POST请求中发送JSON

Question

我收到了一个‘服务器返回的HTTP响应代码: 500’错误，尽管我已经检查了我发送的内容(我甚至尝试使用在线工具发送它，但它工作了)。API密钥和JSON是正确的。当我试图用'connection.getInputStream()‘读取输入流时，我得到了这个错误。这是从哪里来的呢？我是不是忘了什么？我正在尝试通过openrouteservice实现这个特性：https://openrouteservice.org/dev/#/api-docs/v2/directions/{/post}

    public static UPSRoute getRoute(Location start, Location end, String language) {
        if (language.equals("fr")) {
            JSONObject jsonObject = null;

            try {
                URL url = new URL("https://api.openrouteservice.org/v2/directions/foot-walking");
                String payload = "{\"coordinates\":[[" + start.getCoordinates() + "],[" + end.getCoordinates() + "]],\"language\":\"fr\"}";
                System.out.println(payload); //{"coordinates":[[1.463478,43.562038],[1.471717,43.560787]],"language":"fr"}
                byte[] postData = payload.getBytes(StandardCharsets.UTF_8);

                HttpURLConnection connection = (HttpURLConnection)url.openConnection();
                connection.setRequestMethod("POST");
                connection.setRequestProperty("Authorization", API_KEY);
                connection.setRequestProperty("Accept", "application/json, application/geo+json, application/gpx+xml, img/png; charset=utf-8");
                connection.setDoOutput(true);

                try (DataOutputStream wr = new DataOutputStream(connection.getOutputStream())) {
                    wr.write(postData);
                }

                BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream())); // Error is right here
                String inputLine;
                StringBuffer content = new StringBuffer();
                while ((inputLine = in.readLine()) != null) {
                    content.append(inputLine);
                }
                in.close();
                connection.disconnect();

                jsonObject = new JSONObject(content.toString());
            } catch (IOException | JSONException e) {
                e.printStackTrace();
            }

            return new UPSRoute(jsonObject);
        } else {
            return getRoute(start, end);
        }
    }

下面是错误：

java.io.IOException: Server returned HTTP response code: 500 for URL: https://api.openrouteservice.org/v2/directions/foot-walking/json
    at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1913)
    at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1509)
    at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:245)
    at UPSRouteService.getRoute(UPSRouteService.java:63)
    at Main.main(Main.java:5)

Answer 1

多亏了安德烈亚斯，它只是错过了这条线：

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

它现在运行得很好。