的Java HttpsURLConnection的

Question

我試圖從Java這種捲曲的要求執行：

curl -H 'Accept: application/vnd.twitchtv.v2+json' \ 
-d "channel[status]=testing+some+stuff" \ 
-X PUT https://api.twitch.tv/kraken/channels/testacc222?oauth_token=6e7b9cyfi8zk1gr8g06eecebnitlcvb 

我的解決辦法是這樣的：

public static void main(String args[]) throws IOException { 

    String uri = "https://api.twitch.tv/kraken/channels/testacc222?oauth_token=6e7b9cyfi8zk1gr8g06eecebnitlcvb"; 
    URL url = new URL(uri); 

    HttpsURLConnection conn = (HttpsURLConnection) url.openConnection(); 
    conn.setRequestMethod("PUT"); 
    conn.setDoOutput(true); 
    conn.setRequestProperty("Accept", "application/vnd.twitchtv.v2+json"); 

    String data = "channel[status]=testing"; 
    OutputStreamWriter out = new OutputStreamWriter(conn.getOutputStream()); 
    out.write(data); 
    out.flush(); 
    for (Entry<String, List<String>> header : conn.getHeaderFields().entrySet()) { 
     System.out.println(header.getKey() + "=" + header.getValue()); 
    } 
} 

我看不出有什麼問題，但所有的返回是：

Status=[400 Bad Request] 
null=[HTTP/1.1 400 Bad Request] 
Server=[nginx] 
X-Request-Id=[ccc7a9a4a327b18ea4bf496f1f314fb8] 
X-Runtime=[0.032328] 
Connection=[keep-alive] 
X-MH-Cache=[appcache1; M] 
Date=[Sun, 06 Jul 2014 14:07:49 GMT] 
Via=[1.1 varnish] 
Accept-Ranges=[bytes] 
X-Varnish=[2778442693] 
X-UA-Compatible=[IE=Edge,chrome=1] 
Cache-Control=[max-age=0, private, must-revalidate] 
Vary=[Accept-Encoding] 
Content-Length=[83] 
Age=[0] 
X-API-Version=[2] 
Content-Type=[application/json; charset=utf-8] 

我想弄清楚這一個多星期了，我只是沒有看到這個錯誤。任何幫助將不勝感激。

Answer 1

嘗試檢查響應正文，因爲它可能包含有關拒絕的詳細信息。由於內容類型指定utf-8，則可以使用該創建的InputStreamReader：

try (Reader response = 
    new InputStreamReader(conn.getErrorStream(), StandardCharsets.UTF_8)) { 

    int c; 
    while ((c = response.read()) >= 0) { 
     System.out.print((char) c); 
    } 
} 

更新：響應身體指出「通道」參數不存在。這是因爲curl會自動將POST數據編碼爲application/x-www-form-urlencoded，但您的代碼不會。您需要在您的數據上使用URLEncoder，並設置請求的內容類型：

HttpsURLConnection conn = (HttpsURLConnection) url.openConnection(); 
conn.setRequestMethod("PUT"); 
conn.setDoOutput(true); 
conn.setRequestProperty("Accept", "application/vnd.twitchtv.v2+json"); 
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); 

String data = "channel[status]=testing"; 
data = URLEncoder.encode(data, "UTF-8");