Question

当我从我的Activity调用HttpRequests类时，它会抛出NetworkOnMainThreadException，我无法理解为什么会这样做。我把所有网络处理都放在doInBackground方法中。有什么想法吗？

我的AsyncTask：

public class HttpRequests extends AsyncTask<Void, Void, String>{
    private List<NameValuePair> nameValuePairs;
    private String siteUrl;

    public HttpRequests(List<NameValuePair> nameValuePairs, String siteUrl){
        this.nameValuePairs = nameValuePairs;
        this.siteUrl = siteUrl;
    }
    @Override
    protected String doInBackground(Void... params) {

        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost(siteUrl);

        try {
            if (null != nameValuePairs)
                httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

            HttpResponse response = httpclient.execute(httppost);
            response = httpclient.execute(httppost);
            String responseStr = EntityUtils.toString(response.getEntity());

            return responseStr;
        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
        } catch (IOException e) {
            // TODO Auto-generated catch block
        }
        return "";
    }
}

MainActivity中的

：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    HttpRequests request = new HttpRequests(null, "http://google.com");
    request.execute();

}

抛出：

03-22 11:32:43.527    2516-2516/quiz.com.quizapp D/AndroidRuntime﹕ Shutting down VM
03-22 11:32:43.527    2516-2516/quiz.com.quizapp E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: quiz.com.quizapp, PID: 2516
    java.lang.RuntimeException: Unable to start activity ComponentInfo{quiz.com.quizapp/quiz.com.quizapp.MainActivity}: android.os.NetworkOnMainThreadException
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
     Caused by: android.os.NetworkOnMainThreadException
            at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1147)
            at java.net.InetAddress.lookupHostByName(InetAddress.java:418)
            at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
            at java.net.InetAddress.getAllByName(InetAddress.java:215)
            at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
            at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
            at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
            at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
            at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
            at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
            at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
            at quiz.com.quizapp.HttpRequests.makePostHttpRequest(HttpRequests.java:45)
            at quiz.com.quizapp.MainActivity.onCreate(MainActivity.java:23)
            at android.app.Activity.performCreate(Activity.java:5933)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)

Answer 1

从Asynctask扩展你的类，如下所示，

HttpRequests extends AsyncTask<List<NameValuePair> namValuePairs, Void, String> {

public void setUrl(String url) {
    //assign to request
}

@Override
protected JSONObject doInBackground(List<NameValuePair>... params) {

    //your logic
    return return responseStr;

@Override
protected void onPostExecute(String result) {
    // TODO Auto-generated method stub
    super.onPostExecute(result);

}

}

AsyncTask的NetworkOnMainThread问题

1 个答案: