Android 3.0 访问WebService 出现 android.os.NetworkOnMainThreadException异常

以前用2.2 访问WebService没有问题，到3.0上访问出现android.os.NetworkOnMainThreadException

找了资料经过实践，解决方法是在activity类中的onCreate方法中添加strict代码，如下：

 

Java代码  

1. public void onCreate() {    
2.      .......  
3.      StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()       
4.             .detectDiskReads()       
5.             .detectDiskWrites()       
6.             .detectNetwork()   // or .detectAll() for all detectable problems       
7.             .penaltyLog()       
8.             .build());       
9.      StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()       
10.             .detectLeakedSqlLiteObjects()    
11.             .penaltyLog()       
12.             .penaltyDeath()       
13.             .build());    
14.      ......  
15. }    

 

 

似乎是3.0在网络上做了更加严格的限制

packageorg.sword.android;

importjava.util.ArrayList;

importjava.util.List;

importorg.apache.http.HttpResponse;

importorg.apache.http.client.entity.UrlEncodedFormEntity;

importorg.apache.http.client.methods.HttpPost;

importorg.apache.http.impl.client.DefaultHttpClient;

importorg.apache.http.message.BasicNameValuePair;

importorg.apache.http.protocol.HTTP;

importorg.apache.http.util.EntityUtils;

importandroid.app.Activity;

importandroid.os.Bundle;

importandroid.os.StrictMode;

importandroid.widget.Button;

public classInternetActivity extends Activity {

   

private staticfinal String SERVER_UTL ="http://www.webservicex.net/WeatherForecast.asmx/GetWeatherByZipCode";

private Buttonbutton;

   @Override

    public voidonCreate(Bundle savedInstanceState) {

       super.onCreate(savedInstanceState);

       setContentView(R.layout.main);

       

       StrictMode.setThreadPolicy(newStrictMode.ThreadPolicy.Builder()

       .detectDiskReads()

       .detectDiskWrites()

       .detectNetwork()   // or.detectAll() for all detectable problems

       .penaltyLog()

       .build());

       StrictMode.setVmPolicy(newStrictMode.VmPolicy.Builder()

       .detectLeakedSqlLiteObjects()

       .detectLeakedClosableObjects()

       .penaltyLog()

       .penaltyDeath()

       .build());

       getWeather();

    }

   

    private voidgetWeather(){

       try {

              final String SERVER_URL ="http://webservice.webxml.com.cn/WebServices/WeatherWS.asmx/getWeather";// 定义需要获取的内容来源地址

              HttpPost request = newHttpPost(SERVER_URL); // 根据内容来源地址创建一个Http请求

              List params = newArrayList();

              params.add(newBasicNameValuePair("theCityCode", "长沙")); // 添加必须的参数

              params.add(newBasicNameValuePair("theUserID", "")); // 添加必须的参数

              request.setEntity(newUrlEncodedFormEntity(params, HTTP.UTF_8)); // 设置参数的编码

              HttpResponse httpResponse =new DefaultHttpClient().execute(request); // 发送请求并获取反馈

              // 解析返回的内容

              if(httpResponse.getStatusLine().getStatusCode() != 404)

              {

                     Stringresult =EntityUtils.toString(httpResponse.getEntity());

                    System.out.println("result =" + result);

              }

       } catch (Exception e) {

       e.printStackTrace();

       }

}

}