执行URL get，执行url get时出错

Question

我想执行一个简单的urlget，我用了这个里面的代码link http://developer.android.com/reference/java/net/HttpURLConnection.html

我想运行点击事件中的这段代码：

URL url = new URL("http://www.android.com/");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
try {
    InputStream in = new BufferedInputStream(urlConnection.getInputStream());
    readStream(in);}
finally {
    urlConnection.disconnect();
}

当我运行应用程序时，我收到这么长的错误：

E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.soma.smsserver1, PID: 20664 java.lang.IllegalStateException: Could not execute method for android:onClick at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:289) at android.view.View.performClick(View.java:5198) at android.view.View$PerformClick.run(View.java:21147) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5417) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) Caused by: java.lang.reflect.InvocationTargetException at java.lang.reflect.Method.invoke(Native Method) at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:284) at android.view.View.performClick(View.java:5198) at android.view.View$PerformClick.run(View.java:21147) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5417) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) Caused by: android.os.NetworkOnMainThreadException at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1273) at java.net.InetAddress.lookupHostByName(InetAddress.java:431) at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252) at java.net.InetAddress.getAllByName(InetAddress.java:215) at com.android.okhttp.internal.Network.resolveInetAddresses(Network.java:29) at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:188) at com.android.okhttp.internal.http.RouteSelector.nextProxy(RouteSelector.java:157) at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:100) at com.android.okhttp.internal.http.HttpEngine.createNextConnection(HttpEngine.java:357) at com.android.okhttp.internal.http.HttpEngine.nextConnection(HttpEngine.java:340) at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:330) at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:248) at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:433) at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:384) at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:231) at com.example.soma.smsserver1.MainActivity$override.clickMe(MainActivity.java:28) at com.example.soma.smsserver1.MainActivity$override.access$dispatch(MainActivity.java) at com.example.soma.smsserver1.MainActivity.clickMe(MainActivity.java:0) at java.lang.reflect.Method.invoke(Native Method) at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:284) at android.view.View.performClick(View.java:5198) at android.view.View$PerformClick.run(View.java:21147) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5417) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

Answer 1

android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1273)

您无法在主线程上处理网络，这是对 Android 的安全限制，请尝试将您的调用包装在 AsyncTask 后台服务或线程中。

请阅读有关 Processes and Threads

的文档

Answer 2

您正在 MainThread 上执行网络请求，这是被禁止的，因为它会在此调用期间阻塞 UI。您应该使用另一个 Thread 来执行此调用，您有不同的选择：Thread、AsyncTask 等...

这里有一些例子： http://android-developers.blogspot.com/2010/07/multithreading-for-performance.html

Answer 3

您正在主线程上处理网络，这会使您的应用程序挂起，因此您需要在 AsyncTask 等后台服务上处理长运行任务检查这个 link https://www.upwork.com/hiring/mobile/why-you-should-use-asynctask-in-android-development/

执行URL get，执行url get时出错

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