HttpUrlConnection getOutputStream throws

Question

我试图让我的应用程序使用HttpUrlConnection与我的php服务器进行通信。我在我的电脑上写了一个很好的类，但是当我在手机上执行它时，它根本不工作。

这是我的代码：

            String data = "username=" + URLEncoder.encode(username, "UTF-8") + "&password=" + URLEncoder.encode(password, "UTF-8") + "&remember=1";
            connection = (HttpURLConnection) new URL(BASE_URL + "user/login/app").openConnection();
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            connection.setRequestProperty("Content-Length", String.valueOf(data.length()));
            connection.setDoInput(true);
            connection.setDoOutput(true);
            DataOutputStream out = new DataOutputStream(connection.getOutputStream());
            out.writeBytes(data);
            out.flush();
            out.close();

行DataOutputStream(connection.getOutputStream())；out = DataOutputStream引发此异常：

E/Cloud   (10393): java.io.IOException
E/Cloud   (10393):  at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:85)
E/Cloud   (10393):  at libcore.net.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:194)
E/Cloud   (10393):  at com.andryr.runningpal.data.cloud.Cloud.login(Cloud.java:139)
E/Cloud   (10393):  at com.andryr.runningpal.data.SessionList$2.onLogin(SessionList.java:177)
E/Cloud   (10393):  at com.andryr.runningpal.ui.dialog.LoginDialogFragment$2.onClick(LoginDialogFragment.java:56)
E/Cloud   (10393):  at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:169)
E/Cloud   (10393):  at android.os.Handler.dispatchMessage(Handler.java:99)
E/Cloud   (10393):  at android.os.Looper.loop(Looper.java:154)
E/Cloud   (10393):  at android.app.ActivityThread.main(ActivityThread.java:4624)
E/Cloud   (10393):  at java.lang.reflect.Method.invokeNative(Native Method)
E/Cloud   (10393):  at java.lang.reflect.Method.invoke(Method.java:511)
E/Cloud   (10393):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:809)
E/Cloud   (10393):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:576)
E/Cloud   (10393):  at dalvik.system.NativeStart.main(Native Method)

我在我的电脑上测试了这段代码，它不会抛出任何异常。我的舱单：

    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.INTERNET" />

谢谢

Answer 1

可能您试图在UI线程上执行网络操作，Android 3.0+设备不允许这样做。它们将引发一个异常，指示您正在UI线程上执行网络操作。

尝试使用AsyncTask或单独的Thread来执行网络操作。