Android中的HTTP POST，强制关闭？

问题描述：

我试图通过Android发送一个简单的HTTP请求，当我按下某个按钮时。但每次我这样做，我的应用程序部队就会关闭。为什么？顺便说一句，我是Android新手。Android中的HTTP POST，强制关闭？

我的代码：

HttpClient httpclient = new DefaultHttpClient(); 
HttpPost httppost = new HttpPost("http://www.office.school-blog.de/api/check-login.php"); 

try { 
    // Add your data 
    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2); 
    nameValuePairs.add(new BasicNameValuePair("User", "Steffen")); 
    nameValuePairs.add(new BasicNameValuePair("Password", "test1234")); 
    httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); 

    // Execute HTTP Post Request 
    HttpResponse response = httpclient.execute(httppost); 

} catch (ClientProtocolException e) { 
    // TODO Auto-generated catch block 
} catch (IOException e) { 
    // TODO Auto-generated catch block 
}

我的日志文件：

03-16 14:36:47.554: D/AndroidRuntime(449): Shutting down VM 
03-16 14:36:47.554: W/dalvikvm(449): threadid=1: thread exiting with uncaught exception (group=0x40014760) 
03-16 14:36:47.574: E/AndroidRuntime(449): FATAL EXCEPTION: main 
03-16 14:36:47.574: E/AndroidRuntime(449): android.os.NetworkOnMainThreadException 
03-16 14:36:47.574: E/AndroidRuntime(449): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1077) 
03-16 14:36:47.574: E/AndroidRuntime(449): at java.net.InetAddress.lookupHostByName(InetAddress.java:477) 
03-16 14:36:47.574: E/AndroidRuntime(449): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:277) 
03-16 14:36:47.574: E/AndroidRuntime(449): at java.net.InetAddress.getAllByName(InetAddress.java:249) 
03-16 14:36:47.574: E/AndroidRuntime(449): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:136) 
03-16 14:36:47.574: E/AndroidRuntime(449): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164) 
03-16 14:36:47.574: E/AndroidRuntime(449): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119) 
03-16 14:36:47.574: E/AndroidRuntime(449): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360) 
03-16 14:36:47.574: E/AndroidRuntime(449): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555) 
03-16 14:36:47.574: E/AndroidRuntime(449): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487) 
03-16 14:36:47.574: E/AndroidRuntime(449): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465) 
03-16 14:36:47.574: E/AndroidRuntime(449): at com.shr.khg.DashboardActivity$1.onClick(DashboardActivity.java:89) 
03-16 14:36:47.574: E/AndroidRuntime(449): at android.view.View.performClick(View.java:3110) 
03-16 14:36:47.574: E/AndroidRuntime(449): at android.view.View$PerformClick.run(View.java:11934) 
03-16 14:36:47.574: E/AndroidRuntime(449): at android.os.Handler.handleCallback(Handler.java:587) 
03-16 14:36:47.574: E/AndroidRuntime(449): at android.os.Handler.dispatchMessage(Handler.java:92) 
03-16 14:36:47.574: E/AndroidRuntime(449): at android.os.Looper.loop(Looper.java:132) 
03-16 14:36:47.574: E/AndroidRuntime(449): at android.app.ActivityThread.main(ActivityThread.java:4123) 
03-16 14:36:47.574: E/AndroidRuntime(449): at java.lang.reflect.Method.invokeNative(Native Method) 
03-16 14:36:47.574: E/AndroidRuntime(449): at java.lang.reflect.Method.invoke(Method.java:491) 
03-16 14:36:47.574: E/AndroidRuntime(449): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841) 
03-16 14:36:47.574: E/AndroidRuntime(449): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599) 
03-16 14:36:47.574: E/AndroidRuntime(449): at dalvik.system.NativeStart.main(Native Method) 
03-16 14:36:50.064: I/Process(449): Sending signal. PID: 449 SIG: 9

有谁知道什么是错？

首先，在任何情况下，如果出现错误，你应该读错误堆栈跟踪。 'android.os.NetworkOnMainThreadException' - 关于主线程异常的网络...如果你不明白这是什么来自异常类型，只是谷歌它。首先链接到developer.android.com。第一句话是：'应用程序试图在其主线程上执行联网操作时引发的异常。所以了解自己的错误非常简单。 – 2013-03-16 15:35:57

答

使用AsyncTask。

不要做在主线程中的网络操作：这是不允许的Android版本> = 3.0。在doInBackground方法

做网络操作。

阅读here。

答

Android不允许阻塞的任务，如在UI的网络接入（或主）线程。这是所有与用户交互操作有关的线程运行。因此，您需要创建（可能）和AsynTask类来运行查询并将信息反馈回来。见http://developer.android.com/reference/android/os/AsyncTask.html。一个的AsyncTask的一个例子也是在这里给出：http://www.javasrilankansupport.com/2012/11/asynctask-android-example-asynctask-in.html

答

You are trying to perform network operation on UI thread，尽量采取单独的线程或异步任务

答

这将解决你的问题：

class MyHttpPost extends AsyncTask<String, Void, Boolean> { 
@Override 
protected Boolean doInBackground(String... params) 
{ 

HttpClient httpclient = new DefaultHttpClient(); 
HttpPost httppost = new HttpPost("http://www.office.school-blog.de/api/check-login.php"); 

     try { 
     // Add your data 
     List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2); 
     nameValuePairs.add(new BasicNameValuePair("User", "Steffen")); 
     nameValuePairs.add(new BasicNameValuePair("Password", "test1234")); 
     httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); 

     // Execute HTTP Post Request 
     HttpResponse response = httpclient.execute(httppost); 
    HttpEntity httpEntity = response.getEntity(); 
       String result = httpEntity.getContent(); 


     } catch (ClientProtocolException e) { 
     // TODO Auto-generated catch block 
     } catch (IOException e) { 
     // TODO Auto-generated catch block 
     } 



return true; 
        } 

}

替换上述代码public class，因为MyHttpPost类是内部类，所以我们不会为它创建单独的.java文件。

要使用它：

所有的

new MyHttpPost().execute();

Android中的HTTP POST，强制关闭？

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