Java HttpsURLConnection - Spotify 授权 API

Question

几天来我一直在努力让它发挥作用。我正在尝试使用 Java 使用客户端凭据授权流程向 Spotify 进行授权。但是，尽管有 Content-Length 属性.

，我仍然收到 411 Length Required HTTP 错误

HttpsURLConnection spotifyAccounts = null;
            try {
                spotifyAccounts = (HttpsURLConnection) new URL("https://accounts.spotify.com/api/token?grant_type=client_credentials").openConnection();
                spotifyAccounts.setDoOutput(true);
                spotifyAccounts.setDoInput(true);
                spotifyAccounts.setRequestMethod("POST");
                String unencodedAuthorizationKey = "Basic " + "42f48d16044a4c79b5168c5784889827" + ":" + "d6bb7a72e99342319e6b6d8c6fd3cedd";
                String encodedKey = Base64.getEncoder().encodeToString(unencodedAuthorizationKey.getBytes());
                spotifyAccounts.setRequestProperty("Authorization", encodedKey);
                spotifyAccounts.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
                spotifyAccounts.setRequestProperty("User-Agent", "Mozilla/5.0");
                int totalLength = 0;
                for(Entry<String, List<String>> entry : spotifyAccounts.getRequestProperties().entrySet()) {
                    for(String string : entry.getValue()) {
                        totalLength += string.getBytes().length;
                    }
                }
                spotifyAccounts.setRequestProperty("Content-Length", String.valueOf(totalLength));
                spotifyAccounts.connect();
            } catch(IOException ex) {}

每次遇到411错误，我都会输出Content-Length请求属性的值，像这样：

int code = 0;
            try {
                code = spotifyAccounts.getResponseCode();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
            if(code != 200) {
                if(code == 411) {
                    System.out.println("Spotify Accounts - Content-Length: " + spotifyAccounts.getContentLength());
                    System.out.println("Spotify Accounts - Connecting User Agent: " + spotifyAccounts.getRequestProperty("User-Agent"));
                }
                // Other error code handling
            }

输出 Content-Length 总是 return 值 1564。

我尝试了很多方法，例如将 HttpsURLConnection 更改为 HttpURLConnection，更改 Content-Type header，并直接将 Content-Length 设置为 0。但是所有这些解决方案仍然return 411 要求长度错误。还有什么我想念的，还是我误解了什么？

Answer 1

Spotify 文档说您需要在请求正文中设置 grant_type，但是 ?grant_type=client_credentials 这不起作用。相反，您可以像这样提交正文：

    byte[] input = "grant_type=client_credentials".getBytes(StandardCharsets.UTF_8);
    try (OutputStream os = connection.getOutputStream()) {
        os.write(input);
    }

Java HttpsURLConnection - Spotify 授权 API

Java HttpsURLConnection - Authorization with Spotify API

java

api

authorization

spotify