我不知道如何解决（android.os.networkonmainthreadexception）_Android

我不知道如何解决（android.os.networkonmainthreadexception）

android

我不知道如何解决（android.os.networkonmainthreadexception）,android,Android,我总是犯这个错误 public class FlightAvailabityGoActivity extends ListActivity { String[] monthName = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" }; date userDate=new date();

我总是犯这个错误

   public class FlightAvailabityGoActivity extends ListActivity {
String[] monthName = {"Jan", "Feb",
          "Mar", "Apr", "May", "Jun", "Jul",
          "Aug", "Sep", "Oct", "Nov",
          "Dec"
          };


date userDate=new date();
int DepDay=userDate.getDays();
int DepMonth=userDate.getMonths();

bean beanz=new bean();
private TextView fromToTextView;
Calendar calendar = new GregorianCalendar();
  String am_pm;
  String TAG="from";
  private TextView from,to;
  languages lang=new languages();
  String En_Ar=lang.getLang();
  Element dest;

  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {

    try{
    Log.v(TAG, "in go activity       " +TAG);

    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
    setContentView(R.layout.listplaceholder_flightavailabity);
    if(En_Ar.equals("arabic"))
    {
    getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.window_title_flightavailabity_ar);
   // from=(TextView)findViewById(R.id.fromText);
   // from.setText("  من  ");
   // to=(TextView)findViewById(R.id.toText);
    //to.setText("  إلى  ");
    Log.v(TAG, "1       " +TAG);
    }
    else
    {
          Log.v(TAG, "1       " +TAG);
    getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE,  
     R.layout.window_title_flightavailabity);
    }






    ////
    Bundle extras = getIntent().getExtras();

    String FromCity = extras.getString("from");
    String ToCity = extras.getString("to");
    Log.v(TAG, "from city after moving   " +FromCity);
    Log.v(TAG, "to city after moving   " +ToCity);






    ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();
    ArrayList<HashMap<String, String>> mylist1 = new ArrayList<HashMap<String, String>>();

    Log.v(TAG, "2       " +TAG);
    //String xml = XMLfunctions.getXMLFlightAva(FromCity,ToCity);
    String xml=XMLfunctions.getXMLFlightAva(FromCity,ToCity);  // error is here
    Log.v(TAG, "3      " +TAG);  // this will not display
    xml=xml.trim();
    Log.v(TAG, "4       " +TAG);

这是一节课

             public class XMLfunctions {
             String TAG;



public final static Document XMLfromString(String xml){


    Document doc = null;

    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    try {

        DocumentBuilder db = dbf.newDocumentBuilder();

        InputSource is = new InputSource();
        is.setCharacterStream(new StringReader(xml));
        doc = db.parse(is); 

    } catch (ParserConfigurationException e) {
        System.out.println("XML parse error: " + e.getMessage());
        return null;
    } catch (SAXException e) {
        System.out.println("Wrong XML file structure: " + e.getMessage());
        return null;
    } catch (IOException e) {
        System.out.println("I/O exeption: " + e.getMessage());
        return null;
    }

    return doc;

}

/** Returns element value
  * @param elem element (it is XML tag)
  * @return Element value otherwise empty String
  */
 public final static String getElementValue( Node elem ) {
     Node kid;
     if( elem != null){
         if (elem.hasChildNodes()){
             for( kid = elem.getFirstChild(); kid != null; kid = kid.getNextSibling() ){
                 if( kid.getNodeType() == Node.TEXT_NODE  ){
                     return kid.getNodeValue();
                 }
             }
         }
     }
     return "";
 }
 ////////////////////////
 public static String getXMLFlightInfo(String Y_or_T){   
        String line = null;
        String TAG="TAG";
        date userDate=new date();
        int DepDay=userDate.getDays();
        int DepMonth=userDate.getMonths();



        try {

            DefaultHttpClient httpClient = new DefaultHttpClient();
        //  HttpPost httpPost = new HttpPost("http://p-xr.com/xml");
            //HttpGet httpPost=new HttpGet("http://10.128.11.206:9080/mobile/FlightSchdIphoneServlet?depCity="+fromCity+"&arrCity="+toCity+"&day="+DepDay+"&month="+DepMonth+"");
            //HttpGet httpPost=new HttpGet("http://mysv.net.sa/Web/mobile/FlightAvailIphoneServlet?depCity=JED&arrCity=RUH&day=29&month=11&submit=+GO+");
            HttpGet httpPost=new HttpGet("http://10.131.13.43:9080/onlineSMS/xmlFlightInfo.html");

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            line = EntityUtils.toString(httpEntity);



        } catch (UnsupportedEncodingException e) {
            line = "<array status=\"error\"><msg>Can't connect to server</msg></array>";
        } catch (MalformedURLException e) {
            line = "<array status=\"error\"><msg>Can't connect to server</msg></array>";
        } catch (IOException e) {
            line = "<array status=\"error\"><msg>Can't connect to server</msg></array>";
        }

        return line;

}

公共类函数{
字符串标签；
公共最终静态文档XMLfromString（字符串xml）{
单据单据=空；
DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance（）；
试一试{
DocumentBuilder db=dbf.newDocumentBuilder（）；
InputSource is=新的InputSource（）；
is.setCharacterStream（新的StringReader（xml））；
doc=db.parse（is）；
}捕获（ParserConfiguration异常e）{
System.out.println（“XML解析错误：+e.getMessage（））；
返回null；
}捕获（SAXE异常）{
System.out.println（“错误的XML文件结构：+e.getMessage（））；
返回null；
}捕获（IOE异常）{
System.out.println（“I/O验证：+e.getMessage（））；
返回null；
}
退货单；
}
/**返回元素值
*@param elem元素（它是XML标记）
*@返回元素值，否则为空字符串
*/
公共最终静态字符串getElementValue（节点元素）{
节点儿童；
if（elem！=null）{
if（elem.hasChildNodes（））{
for（kid=elem.getFirstChild（）；kid！=null；kid=kid.getNextSibling（））{
if（kid.getNodeType（）==Node.TEXT\u节点）{
return kid.getNodeValue（）；
}
}
}
}
返回“”；
}
////////////////////////
公共静态字符串getXMLFlightInfo（字符串Y_或T）{
字符串行=null；
String TAG=“TAG”；
date userDate=新日期（）；
int DepDay=userDate.getDays（）；
int depmount=userDate.getMonths（）；
试一试{
DefaultHttpClient httpClient=新的DefaultHttpClient（）；
//HttpPost HttpPost=新的HttpPost（“http://p-xr.com/xml");
//HttpGet httpPost=新的HttpGet（“http://10.128.11.206:9080/mobile/FlightSchdIphoneServlet?depCity=“+fromCity+”&arrCity=“+toCity+”&day=“+DepDay+”&month=“+DepMonth+”）；
//HttpGet httpPost=新的HttpGet（“http://mysv.net.sa/Web/mobile/FlightAvailIphoneServlet?depCity=JED&arrCity=RUH&day=29&month=11&submit=+GO+”；
HttpGet httpPost=新的HttpGet（“http://10.131.13.43:9080/onlineSMS/xmlFlightInfo.html");
HttpResponse HttpResponse=httpClient.execute（httpPost）；
HttpEntity HttpEntity=httpResponse.getEntity（）；
line=EntityUtils.toString（httpEntity）；
}捕获（不支持的编码异常e）{
line=“无法连接到服务器”；
}捕获（格式错误）{
line=“无法连接到服务器”；
}捕获（IOE异常）{
line=“无法连接到服务器”；
}
回流线；
}

是从API级别9开始引入的，默认行为已在API级别11中更改，简而言之，API级别11不允许在UI线程上执行网络操作（包括HttpClient和HttpUrlConnection）

正确的策略是将网络操作移出UI线程，例如使用

希望对您有所帮助。

我是否只在oncreate（）下添加上述代码，以及xmlfunction方法如何？我是否将其保留在if语句中，或者对我的问题表示歉意，但我是新来的this@user950003，此代码只需要在应用程序启动后运行一次，最好的位置是在MainActivity.onCreate（）中在调用super.onCreate（）之后和执行网络操作的任何调用之前。

             public class XMLfunctions {
             String TAG;



public final static Document XMLfromString(String xml){


    Document doc = null;

    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    try {

        DocumentBuilder db = dbf.newDocumentBuilder();

        InputSource is = new InputSource();
        is.setCharacterStream(new StringReader(xml));
        doc = db.parse(is); 

    } catch (ParserConfigurationException e) {
        System.out.println("XML parse error: " + e.getMessage());
        return null;
    } catch (SAXException e) {
        System.out.println("Wrong XML file structure: " + e.getMessage());
        return null;
    } catch (IOException e) {
        System.out.println("I/O exeption: " + e.getMessage());
        return null;
    }

    return doc;

}

/** Returns element value
  * @param elem element (it is XML tag)
  * @return Element value otherwise empty String
  */
 public final static String getElementValue( Node elem ) {
     Node kid;
     if( elem != null){
         if (elem.hasChildNodes()){
             for( kid = elem.getFirstChild(); kid != null; kid = kid.getNextSibling() ){
                 if( kid.getNodeType() == Node.TEXT_NODE  ){
                     return kid.getNodeValue();
                 }
             }
         }
     }
     return "";
 }
 ////////////////////////
 public static String getXMLFlightInfo(String Y_or_T){   
        String line = null;
        String TAG="TAG";
        date userDate=new date();
        int DepDay=userDate.getDays();
        int DepMonth=userDate.getMonths();



        try {

            DefaultHttpClient httpClient = new DefaultHttpClient();
        //  HttpPost httpPost = new HttpPost("http://p-xr.com/xml");
            //HttpGet httpPost=new HttpGet("http://10.128.11.206:9080/mobile/FlightSchdIphoneServlet?depCity="+fromCity+"&arrCity="+toCity+"&day="+DepDay+"&month="+DepMonth+"");
            //HttpGet httpPost=new HttpGet("http://mysv.net.sa/Web/mobile/FlightAvailIphoneServlet?depCity=JED&arrCity=RUH&day=29&month=11&submit=+GO+");
            HttpGet httpPost=new HttpGet("http://10.131.13.43:9080/onlineSMS/xmlFlightInfo.html");

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            line = EntityUtils.toString(httpEntity);



        } catch (UnsupportedEncodingException e) {
            line = "<array status=\"error\"><msg>Can't connect to server</msg></array>";
        } catch (MalformedURLException e) {
            line = "<array status=\"error\"><msg>Can't connect to server</msg></array>";
        } catch (IOException e) {
            line = "<array status=\"error\"><msg>Can't connect to server</msg></array>";
        }

        return line;

}