HttpURLConnection類返回-1作爲響應代碼

Question

我試圖從API獲取數據通過HttpURLConnection類，但得到IOException，使用一個消息：

Invalid Http response 

然而，當我粘貼URL請求到瀏覽器我」以200作爲響應代碼得到正確的響應。這裏是代碼有什麼失敗：

public static String sendRequest(String url) throws IOException { 
    HttpURLConnection urlConnection = null; 
    String out = null; 
    System.setProperty("http.keepAlive", "false"); 
    try { 
     URL serverAddress = new URL(url); 
     urlConnection = (HttpURLConnection) serverAddress.openConnection(); 
     urlConnection.setReadTimeout(TIME_OUT_LENGTH); 
     urlConnection.setRequestMethod(REQUEST_METHOD_GET); 
     InputStream in = new BufferedInputStream(urlConnection.getInputStream()); 
     out = Connection.readStream(in); 
    } catch (IOException e) { 
     System.out.println(e.getCause()); 
     InputStream is = new BufferedInputStream(urlConnection.getErrorStream()); 
     out = Connection.readStream(is); 
    } finally { 
     urlConnection.disconnect(); 
     System.out.println(out); 
     return out; 
    } 
} 

private static String readStream(InputStream in) throws IOException { 
    String line; 
    BufferedReader r = new BufferedReader(new InputStreamReader(in)); 
    StringBuilder sb = new StringBuilder(); 
    while((line = r.readLine()) != null) 
     sb.append(line); 
    return sb.toString(); 
} 

任何人看到我在做什麼錯？

---編輯----

堆棧跟蹤：

at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1341) 
at java.net.URL.openStream(URL.java:1037) 
at com.urhola.cheddar.connection.Connection.sendRequest(Connection.java:33) 
at com.urhola.cheddar.request.Request.execute(Request.java:63) 
at com.urhola.cheddar.request.LineInformationRequest.execute(LineInformationRequest.java:36) 
at tester.Client.main(Client.java:54) 

Answer 1

好吧，我切換到Apaches HTTP client，它拋出一個異常說URL參數無效。所以我檢查並注意到我發送了一個參數（通常包括空格）而沒有對它們進行編碼。編碼參數後（下面的例子）一切都很好。

URLEncoder.encode(parameter, "UTF-8");