Question

我是Android开发的初学者。我正在尝试开发一个管理FB Event的小应用程序。当我尝试从Grapfh API获取事件时，我遇到了这个问题

这是日志：


11-07 18:40:22.785: D/dalvikvm(418): GC_CONCURRENT freed 634K, 51% free 3331K/6727K, external 1660K/2137K, paused 4ms+5ms
11-07 18:40:23.235: D/dalvikvm(418): GC_CONCURRENT freed 800K, 51% free 3320K/6727K, external 1660K/2137K, paused 4ms+3ms
11-07 18:40:23.595: D/dalvikvm(418): GC_CONCURRENT freed 686K, 52% free 3275K/6727K, external 1660K/2137K, paused 4ms+3ms
11-07 18:40:23.715: W/System.err(418): java.io.FileNotFoundException: https://graph.facebook.com/me
11-07 18:40:23.726: W/System.err(418):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:521)
11-07 18:40:23.726: W/System.err(418):  at org.apache.harmony.luni.internal.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:258)
11-07 18:40:23.726: W/System.err(418):  at it.unisannio.flash.mobile.MainFragment.onSessionStateChange(MainFragment.java:79)
11-07 18:40:23.726: W/System.err(418):  at it.unisannio.flash.mobile.MainFragment.access$0(MainFragment.java:68)
11-07 18:40:23.726: W/System.err(418):  at it.unisannio.flash.mobile.MainFragment$1.call(MainFragment.java:116)
11-07 18:40:23.726: W/System.err(418):  at com.facebook.Session$3$1.run(Session.java:1302)
11-07 18:40:23.726: W/System.err(418):  at android.os.Handler.handleCallback(Handler.java:587)
11-07 18:40:23.726: W/System.err(418):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-07 18:40:23.726: W/System.err(418):  at android.os.Looper.loop(Looper.java:130)
11-07 18:40:23.726: W/System.err(418):  at android.app.ActivityThread.main(ActivityThread.java:3683)
11-07 18:40:23.726: W/System.err(418):  at java.lang.reflect.Method.invokeNative(Native Method)
11-07 18:40:23.726: W/System.err(418):  at java.lang.reflect.Method.invoke(Method.java:507)
11-07 18:40:23.726: W/System.err(418):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
11-07 18:40:23.735: W/System.err(418):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
11-07 18:40:23.735: W/System.err(418):  at dalvik.system.NativeStart.main(Native Method)
11-07 18:40:25.314: D/dalvikvm(418): GC_CONCURRENT freed 621K, 52% free 3280K/6727K, external 2046K/2137K, paused 4ms+3ms
11-07 18:40:27.314: W/InputManagerService(60): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@40761408
11-07 18:40:29.314: D/dalvikvm(295): GC_EXPLICIT freed 637K, 40% free 7291K/12039K, external 1625K/2137K, paused 104ms
11-07 18:41:27.998: I/dalvikvm(295): Jit: resizing JitTable from 2048 to 4096

这是代码：

try {
          URL url = new URL("https://graph.facebook.com/me");
          HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
          BufferedReader read = new BufferedReader(new InputStreamReader(connection.getInputStream()));
          String line = read.readLine();

          String html = "";
          while(line!=null) {
            html += line;
            line = read.readLine();
          }
        userInfoTextView.setText(line);
        } catch(MalformedURLException ex) {
                ex.printStackTrace();
        } catch(IOException ioex) {
                ioex.printStackTrace();
        }

Answer 1

显然org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl，即运行时环境中使用的HttpURLConnection的实现，当响应status code为400及以上（错误）时，将抛出FileNotFoundException。<登记/> 您可以在此类的源代码中看到它：

/*
* if the requested file does not exist, throw an exception formerly the
* Error page from the server was returned if the requested file was
* text/html this has changed to return FileNotFoundException for all
* file types
*/
if (responseCode >= HTTP_BAD_REQUEST) {
   throw new FileNotFoundException(url.toString());
}

在您的情况下，如果您要检查从此URL返回的响应，您将看到获得400状态代码（错误请求），并显示以下错误：

{
   "error": {
      "message": "An active access token must be used to query information about the current user.",
      "type": "OAuthException",
      "code": 2500
   }
}

您可以致电getResponseCode()：

查看回复代码

int status = connection .getResponseCode();

您可以在Facebook API documentation

中详细了解需要完成的工作

当我在HTTP请求中使用Get Method时，java.io.FileNotFoundException

1 个答案: