我尝试使用HttpUrlConnection使我的应用程序与我的php服务器通信.我写了一个在我的电脑上工作正常的课程但是当我在手机上执行它时根本不起作用.

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 out = new DataOutputStream(connection.getOutputStream());抛出此异常：

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)

我在我的计算机上测试了这段代码,并没有抛出任何异常.
我的清单：

    <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

解决方法:

您可能正在尝试在UI线程上执行网络操作,而Android 3.0设备将不允许这样做.它们将抛出异常,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.