Question

我正在尝试从服务器注销。但是它会返回“0”响应代码并带有此异常。我正在使用GET动词来做这件事。

的logcat

10-17 14:54:13.261: W/System.err(868): java.io.IOException: Received authentication challenge is null
10-17 14:54:13.284: W/System.err(868):  at libcore.net.http.HttpURLConnectionImpl.processAuthHeader(HttpURLConnectionImpl.java:397)
10-17 14:54:13.284: W/System.err(868):  at libcore.net.http.HttpURLConnectionImpl.processResponseHeaders(HttpURLConnectionImpl.java:345)
10-17 14:54:13.304: W/System.err(868):  at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:276)
10-17 14:54:13.324: W/System.err(868):  at libcore.net.http.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:479)
10-17 14:54:13.324: W/System.err(868):  at com.remote.synchronizer.haris.CustomHttpClient.executeGet(CustomHttpClient.java:131)
10-17 14:54:13.354: W/System.err(868):  at com.remote.synchronizer.haris.OptionsActivity$1$3$1.run(OptionsActivity.java:87)
10-17 14:54:13.364: W/System.err(868):  at android.os.Handler.handleCallback(Handler.java:605)
10-17 14:54:13.384: W/System.err(868):  at android.os.Handler.dispatchMessage(Handler.java:92)
10-17 14:54:13.384: W/System.err(868):  at android.os.Looper.loop(Looper.java:137)
10-17 14:54:13.404: W/System.err(868):  at android.app.ActivityThread.main(ActivityThread.java:4424)
10-17 14:54:13.424: W/System.err(868):  at java.lang.reflect.Method.invokeNative(Native Method)
10-17 14:54:13.424: W/System.err(868):  at java.lang.reflect.Method.invoke(Method.java:511)
10-17 14:54:13.454: W/System.err(868):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
10-17 14:54:13.474: W/System.err(868):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
10-17 14:54:13.474: W/System.err(868):  at dalvik.system.NativeStart.main(Native Method)
10-17 14:54:13.484: E/HTTP Response(868): java.io.IOException: Received authentication challenge is null

CustomHttpClient.java

public class CustomHttpClient {

    static HttpClient client = new DefaultHttpClient();
    static HttpURLConnection connection = null; 

    public static int executePost(String url, String postParameters)
    {
        int response=0;

        OutputStream output = null;
        try
        {
            connection = (HttpURLConnection)new URL(url).openConnection();
            System.setProperty("http.keepAlive", "false");
            connection.setDoOutput(true);
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Accept-Charset", "UTF-8");
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8");

            connection.connect();

            output = connection.getOutputStream();
            output.write(postParameters.getBytes("UTF-8"));

            response=connection.getResponseCode();
        }
        catch(Exception e)
        {
            e.printStackTrace();
            Log.e("HTTP Response", e.toString());
        }
        finally {
            if(connection != null) {
                //  connection.disconnect(); 
                if (output != null) 
                    try { output.close(); } 
                catch (IOException logOrIgnore) {}
            }
        }

        return response;
    }

    public static int executeGet(String url)
    {
        int response=0;

        //HttpURLConnection connection = null;
        try
        {
            connection = (HttpURLConnection) new URL(url).openConnection();
            System.setProperty("http.keepAlive", "false");
            //connection.setRequestProperty("Accept-Charset", "UTF-8");
            connection.setDoInput(true);
            connection.setRequestMethod("GET");
            connection.connect();
            response=connection.getResponseCode();
        } 
        catch(Exception e)
        {
            e.printStackTrace();
            Log.e("HTTP Response", e.toString());
        }
        finally {
            if(connection != null) {
                //  connection.disconnect();
            }
        }
        return response;
    }

}

在此之前，我在Gingerbird 2.3中使用DefaultHTTPClient，它的工作完美但在ICS DefaultHTTPClient中不起作用，所以我需要使用HttpURLConnection。 POST动词工作正常。

Answer 1

如果在连接对象上第二次调用.getResponseCode（），则可以在异常后获取响应代码。这是因为第一次调用.getResponseCode（）时，会设置一个内部状态，使得.getResponseCode（）能够返回而不会抛出异常。

示例：

HttpURLConnection connection = ...;
try {
    // Will throw IOException if server responds with 401.
    connection.getResponseCode(); 
} catch (IOException e) {
    // Will return 401, because now connection has the correct internal state.
    int responsecode = connection.getResponseCode(); 
}

我也在这里回答了这个问题：https://stackoverflow.com/a/15972969/816017

Answer 2

HttpURLConnection.getResponseCode()在遇到格式错误的HTTP 401标头时抛出java.io.IOException: Received authentication challenge is null。除WWW-Authenticate标头外，您是否从服务器收到Content-Length和HTTP/1.1 401 Unauthorized标头？见IOException: "Received authentication challenge is null" (Apache Harmony/Android)

如果您无法对服务器进行更改，那么您可以捕获该异常（感谢https://stackoverflow.com/a/10904318/262462）

try {
    response=connection.getResponseCode();
}
catch (java.io.IOException e) {
    if (e.getMessage().contains("authentication challenge")) {
        response = HttpsURLConnection.HTTP_UNAUTHORIZED;
    } else { throw e; }
}

Answer 3

此错误发生在服务器发送401（未授权）但未提供“WWW-Authenticate”，这是客户端下一步操作的提示。 “WWW-Authenticate”标题告诉客户端需要哪种身份验证（Basic或Digest）。这在无头http客户端中通常不是很有用，但这就是标准的定义方式。发生此错误是因为lib尝试解析“WWW-Authenticate”标头但不能解析。

如果您可以更改服务器，可能的解决方案：

添加假的“WWW-Authenticate”标题，如：WWW-Authenticate: Basic realm="fake"。这仅仅是一种解决方法而不是解决方案，但它应该可以工作并且http客户端很满意。
使用HTTP状态代码403代替401。它的语义不一样，通常在使用登录401时是正确的响应（see here for detailed discussion），但它足够接近。

如果您无法更改服务器，可能的解决方案：

正如@ErikZ在他的post中写道，你可以试试看＆amp; catch

HttpURLConnection connection = ...;
try {
    // Will throw IOException if server responds with 401.
    connection.getResponseCode(); 
} catch (IOException e) {
    // Will return 401, because now connection has the correct internal state.
    int responsecode = connection.getResponseCode(); 
}

我也在这里发布了这个：java.io.IOException : No authentication challenges found

java.io.IOException：ICS 4.0.3中收到的身份验证质询为null

3 个答案: