Ошибка синтаксического анализа XML

Question

Я пишу приложение для синтаксического анализатора XML в android Но когда я загружаю код и запускаю его, он отлично работает, Но я написал тот же код, но не работал. Почему так?

Есть ли какие-либо предпосылки для этого? Пожалуйста, помогите мне с этим

Я получаю сообщение об ошибке в XMLParser.java

package com.xmlparser; 
import java.io.IOException; 
import java.io.StringReader; 
import java.io.UnsupportedEncodingException; 

import javax.xml.parsers.DocumentBuilder; 
import javax.xml.parsers.DocumentBuilderFactory; 
import javax.xml.parsers.ParserConfigurationException; 

import org.apache.http.HttpEntity; 
import org.apache.http.HttpResponse; 
import org.apache.http.client.ClientProtocolException; 
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.impl.client.DefaultHttpClient; 
import org.apache.http.util.EntityUtils; 
import org.w3c.dom.Document; 
import org.w3c.dom.Element; 
import org.w3c.dom.Node; 
import org.w3c.dom.NodeList; 
import org.xml.sax.InputSource; 
import org.xml.sax.SAXException; 

import android.util.Log; 

public class XMLParser { 

    // constructor 
    public XMLParser() { 

    } 

    /** 
    * Getting XML from URL making HTTP request 
    * @param url string 
    * */ 
    public String getXmlFromUrl(String url) { 
     String xml = null; 

     try { 
      // defaultHttpClient 
      DefaultHttpClient httpClient = new DefaultHttpClient(); 
      HttpPost httpPost = new HttpPost(url); 

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

     } catch (UnsupportedEncodingException e) { 
      e.printStackTrace(); 
     } catch (ClientProtocolException e) { 
      e.printStackTrace(); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
     // return XML 
     return xml; 
    } 

    /** 
    * Getting XML DOM element 
    * @param XML string 
    * */ 
    public Document getDomElement(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) { 
       Log.e("Error: ", e.getMessage()); 
       return null; 
      } catch (SAXException e) { 
       Log.e("Error: ", e.getMessage()); 
       return null; 
      } catch (IOException e) { 
       Log.e("Error: ", e.getMessage()); 
       return null; 
      } 

      return doc; 
    } 

    /** Getting node value 
     * @param elem element 
     */ 
    public final String getElementValue(Node elem) { 
     Node child; 
     if(elem != null){ 
      if (elem.hasChildNodes()){ 
       for(child = elem.getFirstChild(); child != null; child = child.getNextSibling()){ 
        if(child.getNodeType() == Node.TEXT_NODE ){ 
         return child.getNodeValue(); 
        } 
       } 
      } 
     } 
     return ""; 
    } 

    /** 
     * Getting node value 
     * @param Element node 
     * @param key string 
     * */ 
    public String getValue(Element item, String str) {  
      NodeList n = item.getElementsByTagName(str);   
      return this.getElementValue(n.item(0)); 
     } 
} 

Мой журнал Cat

11-22 15:35:53.675: E/AndroidRuntime(19208): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.xmlparser/com.xmlparser.Xparser}: android.os.NetworkOnMainThreadException 
11-22 15:35:53.675: E/AndroidRuntime(19208): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2100) 
11-22 15:35:53.675: E/AndroidRuntime(19208): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2125) 
11-22 15:35:53.675: E/AndroidRuntime(19208): at android.app.ActivityThread.access$600(ActivityThread.java:140) 
11-22 15:35:53.675: E/AndroidRuntime(19208): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1227) 
11-22 15:35:53.675: E/AndroidRuntime(19208): at android.os.Handler.dispatchMessage(Handler.java:99) 
11-22 15:35:53.675: E/AndroidRuntime(19208): at android.os.Looper.loop(Looper.java:137) 
11-22 15:35:53.675: E/AndroidRuntime(19208): at android.app.ActivityThread.main(ActivityThread.java:4898) 
11-22 15:35:53.675: E/AndroidRuntime(19208): at java.lang.reflect.Method.invokeNative(Native Method) 
11-22 15:35:53.675: E/AndroidRuntime(19208): at java.lang.reflect.Method.invoke(Method.java:511) 
11-22 15:35:53.675: E/AndroidRuntime(19208): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1008) 
11-22 15:35:53.675: E/AndroidRuntime(19208): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:775) 
11-22 15:35:53.675: E/AndroidRuntime(19208): at dalvik.system.NativeStart.main(Native Method) 
11-22 15:35:53.675: E/AndroidRuntime(19208): Caused by: android.os.NetworkOnMainThreadException 
11-22 15:35:53.675: E/AndroidRuntime(19208): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1118) 

    11-22 15:19:21.500: E/AndroidRuntime(16631): at java.net.InetAddress.lookupHostByName(InetAddress.java:385) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at java.net.InetAddress.getAllByName(InetAddress.java:214) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:670) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:509) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at com.xmlparser.XMLParser.getXmlFromUrl(XMLParser.java:45) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at com.xmlparser.Xparser.onCreate(Xparser.java:37) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at android.app.Activity.performCreate(Activity.java:5206) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094) 
    11-22 15:19:21.500: E/AndroidRuntime(16631): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2064) 

это мой Xparser.java

package com.xmlparser; 

import java.util.ArrayList; 
import java.util.HashMap; 
import org.w3c.dom.Document; 
import org.w3c.dom.Element; 
import org.w3c.dom.NodeList; 

import android.app.ListActivity; 
import android.content.Intent; 
import android.os.Bundle; 
import android.view.Menu; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.ListAdapter; 
import android.widget.ListView; 
import android.widget.SimpleAdapter; 
import android.widget.TextView; 

public class Xparser extends ListActivity { 
    static final String URL = "http://api.androidhive.info/pizza/?format=xml"; 
    // XML key nodes 
    static final String KEY_ITEM = "item"; 
    static final String KEY_ID = "id"; 
    static final String KEY_NAME = "name"; 
    static final String KEY_COST = "cost"; 
    static final String KEY_DESC = "description"; 


    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_xmlparser); 
     ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>(); 
     XMLParser parser = new XMLParser(); 
     String xml = parser.getXmlFromUrl(URL);// getting XML 
     Document doc = parser.getDomElement(xml);// getting Dom Element 

     NodeList n1 = doc.getElementsByTagName(KEY_ITEM); 
     // looping through all item nodes <item> 
     for(int i=0 ; i < n1.getLength(); i++){ 
      HashMap<String,String> map = new HashMap<String,String>(); 
      Element e = (Element) n1.item(i); 
      //adding each child to Hashmap node key 
      map.put(KEY_ID, parser.getValue(e,KEY_ID)); 
      map.put(KEY_NAME, parser.getValue(e,KEY_NAME)); 
      map.put(KEY_COST, "Rs."+ parser.getValue(e,KEY_COST)); 
      map.put(KEY_DESC, parser.getValue(e,KEY_DESC)); 

      // adding HashList to ArrayList 
      menuItems.add(map); 
     } 

    // Adding menuItems to ListView 
     ListAdapter adapter = new SimpleAdapter(this, menuItems, 
       R.layout.list_select_item, 
       new String[] { KEY_NAME, KEY_DESC, KEY_COST }, new int[] { 
         R.id.name, R.id.desciption, R.id.cost }); 
    setListAdapter(adapter); 


    // selecting single ListView item 
    ListView lv = getListView(); 
    lv.setOnItemClickListener(new OnItemClickListener(){ 
    @Override 
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
     // TODO Auto-generated method stub 
     String name = ((TextView) view.findViewById(R.id.name)).getText().toString(); 
     String cost = ((TextView) view.findViewById(R.id.cost)).getText().toString(); 
     String desc = ((TextView) view.findViewById(R.id.desciption)).getText().toString(); 

     Intent in = new Intent(); 
     in.putExtra(KEY_NAME, name); 
     in.putExtra(KEY_DESC, desc); 
     in.putExtra(KEY_COST, cost); 
     startActivity(in); 
    } 

    }); 
    } 
    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.xmlparser, menu); 
     return true; 
     } 
} 

Answer 1

Исключение tells you everything вам нужно t o знать. Вы пытаетесь отправить данные в основной поток. Выполняйте сетевые операции в отдельном потоке.

There's a link in the docs that explains it, и this might help you to move on.