HttpResponse執行只適用於Android API 8和API 10

Question

我有一個xml解析器，可以在模擬器的Android api 8和10上正常工作（我的設備上有api 10，並且工作效果很好），但嘗試模擬更高的api，我錯誤的HTTP請求。這裏是Parser.class：

package com.muc.horoscop; 

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.auth.UsernamePasswordCredentials; 
import org.apache.http.client.ClientProtocolException; 
import org.apache.http.client.HttpClient; 
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.impl.auth.BasicScheme; 
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 { 


public XMLParser() { 

} 

/** 
* Getting XML from URL making HTTP request 
* @param url string 
* */ 


public String getXmlFromUrl(String url) { 
    String xml = new String(); 

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

//   httpPost.addHeader(BasicScheme.authenticate(
//   new UsernamePasswordCredentials("client_ro", "+_lklklkl*/544pF"),"UTF-8", false)); 


     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)); 
    } 
} 

這裏是logcat的

12-31 11:23:31.223: D/AndroidRuntime(442): Shutting down VM 
12-31 11:23:31.223: W/dalvikvm(442): threadid=1: thread exiting with uncaught exception (group=0x40014760) 
12-31 11:23:31.243: E/AndroidRuntime(442): FATAL EXCEPTION: main 
12-31 11:23:31.243: E/AndroidRuntime(442): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.muc.horoscop/com.muc.horoscop.AfisareHoroscop}: android.os.NetworkOnMainThreadException 
12-31 11:23:31.243: E/AndroidRuntime(442): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1815) 
12-31 11:23:31.243: E/AndroidRuntime(442): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1831) 
12-31 11:23:31.243: E/AndroidRuntime(442): at android.app.ActivityThread.access$500(ActivityThread.java:122) 
12-31 11:23:31.243: E/AndroidRuntime(442): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1024) 
12-31 11:23:31.243: E/AndroidRuntime(442): at android.os.Handler.dispatchMessage(Handler.java:99) 
12-31 11:23:31.243: E/AndroidRuntime(442): at android.os.Looper.loop(Looper.java:132) 
12-31 11:23:31.243: E/AndroidRuntime(442): at android.app.ActivityThread.main(ActivityThread.java:4123) 
12-31 11:23:31.243: E/AndroidRuntime(442): at java.lang.reflect.Method.invokeNative(Native Method) 
12-31 11:23:31.243: E/AndroidRuntime(442): at java.lang.reflect.Method.invoke(Method.java:491) 
12-31 11:23:31.243: E/AndroidRuntime(442): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841) 
12-31 11:23:31.243: E/AndroidRuntime(442): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599) 
12-31 11:23:31.243: E/AndroidRuntime(442): at dalvik.system.NativeStart.main(Native Method) 
12-31 11:23:31.243: E/AndroidRuntime(442): Caused by: android.os.NetworkOnMainThreadException 
12-31 11:23:31.243: E/AndroidRuntime(442): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1077) 
12-31 11:23:31.243: E/AndroidRuntime(442): at java.net.InetAddress.lookupHostByName(InetAddress.java:477) 
12-31 11:23:31.243: E/AndroidRuntime(442): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:277) 
12-31 11:23:31.243: E/AndroidRuntime(442): at java.net.InetAddress.getAllByName(InetAddress.java:249) 
12-31 11:23:31.243: E/AndroidRuntime(442): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:136) 
12-31 11:23:31.243: E/AndroidRuntime(442): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164) 
12-31 11:23:31.243: E/AndroidRuntime(442): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119) 
12-31 11:23:31.243: E/AndroidRuntime(442): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360) 
12-31 11:23:31.243: E/AndroidRuntime(442): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555) 
12-31 11:23:31.243: E/AndroidRuntime(442): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487) 
12-31 11:23:31.243: E/AndroidRuntime(442): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465) 
12-31 11:23:31.243: E/AndroidRuntime(442): at com.muc.horoscop.XMLParser.getXmlFromUrl(XMLParser.java:52) 
12-31 11:23:31.243: E/AndroidRuntime(442): at com.muc.horoscop.AfisareHoroscop.onCreate(AfisareHoroscop.java:111) 
12-31 11:23:31.243: E/AndroidRuntime(442): at android.app.Activity.performCreate(Activity.java:4397) 
12-31 11:23:31.243: E/AndroidRuntime(442): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1048) 
12-31 11:23:31.243: E/AndroidRuntime(442): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1779) 
12-31 11:23:31.243: E/AndroidRuntime(442): ... 11 more 

而且在其中創建列表活動類：

public class AfisareHoroscop extends ListActivity { 


    static final String KEY_ITEM = "item"; // parent node 
    static final String KEY_ID = "id"; 
    static final String KEY_DATA = "data"; 
    static final String KEY_SCURT = "scurt"; 
    static final String KEY_DESC = "descriere"; 

    @Override 
    public void onBackPressed() { 
     finish(); 
    } 

    public boolean isOnline() { 
     ConnectivityManager cm = 
      (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); 
     NetworkInfo netInfo = cm.getActiveNetworkInfo(); 
     if (netInfo != null && netInfo.isConnectedOrConnecting()) { 
      return true; 
     } 
     return false; 
    } 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     requestWindowFeature(Window.FEATURE_CUSTOM_TITLE); 

     final String lala = getSharedPreferences("zodialui", MODE_PRIVATE).getString("zodia_consumator", ""); 
     final String url = "http://calina.mucomputers.eu/"+lala+".xml"; 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_afisare_horoscop); 
     //afisare titlu 
     getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.window_title); 
     final String tit_gen = getApplicationContext().getResources().getString(R.string.titlu_gen); 
     final TextView myTitleText = (TextView) findViewById(R.id.titlu); 
     String titlul = new String(tit_gen+" "+lala); 
     SpannableString spanString = new SpannableString(titlul); 
     spanString.setSpan(new StyleSpan(Typeface.BOLD), 0, spanString.length(), 0); 
     myTitleText.setText(spanString); 
     ImageView semn_titlu = (ImageView) findViewById(R.id.imageView2); 
     if (lala.equals("Balanta")) { 
      semn_titlu.setImageResource(R.drawable.balanta); 
     }else if (lala.equals("Berbec")){ 
      semn_titlu.setImageResource(R.drawable.berbec); 
     }else if (lala.equals("Capricorn")){ 
      semn_titlu.setImageResource(R.drawable.capricorn); 
     }else if (lala.equals("Fecioara")){ 
      semn_titlu.setImageResource(R.drawable.fecioara); 
     }else if (lala.equals("Gemeni")){ 
      semn_titlu.setImageResource(R.drawable.gemeni); 
     }else if (lala.equals("Leu")){ 
      semn_titlu.setImageResource(R.drawable.leu); 
     }else if (lala.equals("Pesti")){ 
      semn_titlu.setImageResource(R.drawable.pesti); 
     }else if (lala.equals("Rac")){ 
      semn_titlu.setImageResource(R.drawable.rac); 
     }else if (lala.equals("Sagetator")){ 
      semn_titlu.setImageResource(R.drawable.sagetator); 
     }else if (lala.equals("Scorpion")){ 
      semn_titlu.setImageResource(R.drawable.scorpion); 
     }else if (lala.equals("Taur")){ 
      semn_titlu.setImageResource(R.drawable.taur); 
     }else if (lala.equals("Varsator")){ 
      semn_titlu.setImageResource(R.drawable.varsator); 
     } 
     //afisare titlu 

     if (isOnline() == true) { 

     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 nl = doc.getElementsByTagName(KEY_ITEM); 
     // looping through all item nodes <item> 
     for (int i = 0; i < nl.getLength(); i++) { 
      // creating new HashMap 
      HashMap<String, String> map = new HashMap<String, String>(); 
      Element e = (Element) nl.item(i); 

      // adding each child node to HashMap key => value 
      map.put(KEY_DATA, parser.getValue(e, KEY_DATA)); 
      map.put(KEY_SCURT, parser.getValue(e, KEY_SCURT)); 
      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_item, 
       new String[] { KEY_SCURT, KEY_DATA, KEY_DESC }, new int[] { 
         R.id.scurt, R.id.data, R.id.descriere }); 

     setListAdapter(adapter); 
     Collections.reverse(menuItems); 

     // selecting single ListView item 
     ListView lv = getListView(); 


     lv.setOnItemClickListener(new OnItemClickListener() { 


      @Override 
      public void onItemClick(AdapterView<?> parent, View view, 
        int position, long id) { 
       // getting values from selected ListItem 

       String scurt = ((TextView) view.findViewById(R.id.scurt)).getText().toString(); 
       String data = ((TextView) view.findViewById(R.id.data)).getText().toString(); 
       String descriere = ((TextView) view.findViewById(R.id.descriere)).getText().toString(); 

       // Starting new intent 
       Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class); 
       in.putExtra(KEY_SCURT, scurt); 
       in.putExtra(KEY_DATA, data); 

       in.putExtra(KEY_DESC, descriere); 
       startActivity(in); 

      } 

     }); 
     } else { 

      Button btn = new Button(this); 
      View.OnClickListener myhandler = new View.OnClickListener() { 
       public void onClick(View v) { 
        Intent i = new Intent(AfisareHoroscop.this, AfisareHoroscop.class); //your class 
        startActivity(i); 
        finish(); 
       } 
       }; 
       btn.setOnClickListener(myhandler); 
      btn.setText("Refresh"); 
      RelativeLayout.LayoutParams paramsd = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT ,LayoutParams.WRAP_CONTENT); 
      paramsd.addRule(RelativeLayout.CENTER_IN_PARENT); 
      paramsd.height = 60; 
      paramsd.width = 60; 
      btn.setLayoutParams(paramsd); 
      addContentView(btn,paramsd); 
      Context context = getApplicationContext(); 
      String no_con = getResources().getString(R.string.no_connection); 
      CharSequence text = no_con; 
      int duration = Toast.LENGTH_SHORT; 

      Toast toast = Toast.makeText(context, text, duration); 
      toast.show(); 
     } 

    } 


    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.activity_afisare_horoscop, menu); 
     return true; 
    } 
    public boolean onOptionsItemSelected(MenuItem item) { 
     switch (item.getItemId()) { 
     case R.id.menu_settings: 
      Intent menu_set = new Intent (this, MainActivity.class); 
      finish(); 
      startActivity(menu_set); 
     return true; 
     case R.id.menu_despre: 
     startActivity(new Intent(this, DespreActivity.class)); 
     return true; 
     default: 
     return super.onOptionsItemSelected(item); 
     } 
    } 
} 

我花了2天時間找出什麼發生，那可能是因爲我是初學者。 謝謝！

Answer 1

這個問題有兩個解決方案，但第一個是很好的解決方案。

1）不要在主UI線程中使用異步任務編寫網絡調用。

2）在setContentView（R.layout.activity_main）之後將代碼寫入MainActivity文件中;但這不是正確的方法。

if (android.os.Build.VERSION.SDK_INT > 9) { 
    StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build(); 
    StrictMode.setThreadPolicy(policy); 
} 

和下面的import語句放到你的java文件中。

import android.os.StrictMode; 

並參見下面的鏈接瞭解更多信息。

Caused by: android.os.NetworkOnMainThreadException