嘗試使用HtmlCleaner和XPath解析html

Question

我試圖從某個網站獲取表數據（this is the website），並試圖通過嘗試獲取某個節點來嘗試它。這裏是我的嘗試：

public class ScheudeleWithDesign extends Activity { 

static final String urlToParse = "https://www.easistent.com/urniki/263/razredi/18221"; 
static final String xpathTableContents = "//div[@id='text11']/td/tr"; 
TextView tw1; 

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

    tw1 = (TextView) findViewById(R.id.urnikText); 

    String value = ""; 

    try { 
     value = getScheudele(); 
     tw1.setText(value); 
    } catch (IOException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } catch (XPatherException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 

}//End of onCreate 

public String getScheudele() throws IOException, XPatherException{ 
    String stats = null; 

    //cleaner properties 
    HtmlCleaner cleaner = new HtmlCleaner(); 
    CleanerProperties props = cleaner.getProperties(); 
    props.setAllowHtmlInsideAttributes(false); 
    props.setAllowMultiWordAttributes(false); 
    props.setRecognizeUnicodeChars(true); 
    props.setOmitComments(true); 

    //URL object 
    URL url = new URL(urlToParse); 

    //HTML page root node 
    TagNode root = cleaner.clean(url); 

    //query XPath 
    Object[] node = root.evaluateXPath(xpathTableContents); 

    //Vzemi podatke če najdeš element 
    if (node.length > 0) { 
     TagNode resultNode = (TagNode)node[0]; 
     stats = resultNode.getText().toString(); 
    } 

    return stats; 
} 

這不起作用，應用程序崩潰，這它的logcat：

09-22 11:22:08.632: E/AndroidRuntime(29385): FATAL EXCEPTION: main 
09-22 11:22:08.632: E/AndroidRuntime(29385): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.whizzapps.stpsurniki/com.whizzapps.stpsurniki.ScheudeleWithDesign}: android.os.NetworkOnMainThreadException 
09-22 11:22:08.632: E/AndroidRuntime(29385): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at android.app.ActivityThread.access$600(ActivityThread.java:141) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at android.os.Handler.dispatchMessage(Handler.java:99) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at android.os.Looper.loop(Looper.java:137) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at android.app.ActivityThread.main(ActivityThread.java:5103) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at java.lang.reflect.Method.invokeNative(Native Method) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at java.lang.reflect.Method.invoke(Method.java:525) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at dalvik.system.NativeStart.main(Native Method) 
09-22 11:22:08.632: E/AndroidRuntime(29385): Caused by: android.os.NetworkOnMainThreadException 
09-22 11:22:08.632: E/AndroidRuntime(29385): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1133) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at java.net.InetAddress.lookupHostByName(InetAddress.java:385) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at java.net.InetAddress.getAllByName(InetAddress.java:214) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at libcore.net.http.HttpConnection.connect(HttpConnection.java:128) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.makeSslConnection(HttpsURLConnectionImpl.java:461) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.connect(HttpsURLConnectionImpl.java:433) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:282) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:177) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at libcore.net.http.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:271) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at java.net.URL.openStream(URL.java:462) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at org.htmlcleaner.Utils.readUrl(Utils.java:63) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at org.htmlcleaner.HtmlCleaner.clean(HtmlCleaner.java:373) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at org.htmlcleaner.HtmlCleaner.clean(HtmlCleaner.java:387) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at com.whizzapps.stpsurniki.ScheudeleWithDesign.getScheudele(ScheudeleWithDesign.java:63) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at com.whizzapps.stpsurniki.ScheudeleWithDesign.onCreate(ScheudeleWithDesign.java:36) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at android.app.Activity.performCreate(Activity.java:5133) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
09-22 11:22:08.632: E/AndroidRuntime(29385): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175) 
09-22 11:22:08.632: E/AndroidRuntime(29385): ... 11 more 

Answer 1

當應用程序試圖執行 網絡操作時引發的異常在其主線上。

這僅適用於針對Honeycomb SDK或 的應用程序。應用針對早期SDK版本被允許這樣做 他們的主事件循環線程聯網，但它是沉重 氣餒

來源：http://developer.android.com/reference/android/os/NetworkOnMainThreadException.html

解決方案＃1：

執行在網絡通話一個分離的線程，嘗試使用AsyncTask。

解決方案2：

您可以使用StrictMode對象允許 '在主線程上網絡'。

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

P.S：使用它，只有你完全理解這個解決方案的副作用。 你可以找到更多關於StrictMode here的信息。