我正在尝试从服务器注销。但它返回“0”响应代码，但有此异常。我正在使用 GET 动词来执行此操作。

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，它工作得很好，但在 ICS 中 DefaultHTTPClient 不工作，所以我需要使用 HttpURLConnection。 POST 动词工作正常。

最佳答案

如果您在连接对象上第二次调用 .getResponseCode() ，您可以获得异常后的响应代码。这是因为您第一次调用 .getResponseCode() 时设置了一个内部状态，使 .getResponseCode() 能够返回而不抛出异常。

例子:

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(); 
}

我在这里也回答了这个问题:https://stackoverflow.com/a/15972969/816017

关于android - java.io.IOException : Received authentication challenge is null in ICS 4. 0.3，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/12931791/