MySQL的登錄和註冊

Question

我下面在Android上登錄的優秀教程，並註冊在http://www.androidhive.info/2012/01/android-login-and-registration-with-php-mysql-and-sqlite/

我已經實現了代碼爲我自己的項目，但我一直在得到錯誤。所以我決定嘗試一下，如果他的代碼正在工作，它確實沒問題。經過幾個小時的搜尋，我才決定複製他的代碼並從那裏出發。但即使只是將他的代碼複製粘貼到我的項目中，我仍然不斷收到錯誤。

這是我的logcat錯誤，如果任何人都可以指出我在正確的方向我會很高興。

01-15 10:12:26.822: E/AndroidRuntime(1935): FATAL EXCEPTION: main 
01-15 10:12:26.822: E/AndroidRuntime(1935): android.os.NetworkOnMainThreadException 
01-15 10:12:26.822: E/AndroidRuntime(1935): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)           
01-15 10:12:26.822: E/AndroidRuntime(1935):  at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at libcore.io.IoBridge.connectErrno(IoBridge.java:127) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at libcore.io.IoBridge.connect(IoBridge.java:112) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at java.net.Socket.connect(Socket.java:842) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at com.example.androidbasic12.library.JSONParser.getJSONFromUrl(JSONParser.java:42) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at com.example.androidbasic12.library.UserFunctions.loginUser(UserFunctions.java:38) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at com.example.androidbasic12.MainActivity$1.onClick(MainActivity.java:57) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at android.view.View.performClick(View.java:4202) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at android.view.View$PerformClick.run(View.java:17340) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at android.os.Handler.handleCallback(Handler.java:725) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at android.os.Handler.dispatchMessage(Handler.java:92) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at android.os.Looper.loop(Looper.java:137) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at android.app.ActivityThread.main(ActivityThread.java:5039) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at java.lang.reflect.Method.invokeNative(Native Method) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at java.lang.reflect.Method.invoke(Method.java:511) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 
01-15 10:12:26.822: E/AndroidRuntime(1935):  at dalvik.system.NativeStart.main(Native Method)` 

JSONParser.class：

public class JSONParser { 

static InputStream is = null; 
static JSONObject jObj = null; 
static String json = ""; 

// constructor 
public JSONParser() { 

} 

public JSONObject getJSONFromUrl(String url, List<NameValuePair> params) { 

    // Making HTTP request 
    try { 
     // defaultHttpClient 
     DefaultHttpClient httpClient = new DefaultHttpClient(); 
     HttpPost httpPost = new HttpPost(url); 
     httpPost.setEntity(new UrlEncodedFormEntity(params)); 

     HttpResponse httpResponse = httpClient.execute(httpPost); 
     HttpEntity httpEntity = httpResponse.getEntity(); 
     is = httpEntity.getContent(); 

    } catch (UnsupportedEncodingException e) { 
     e.printStackTrace(); 
    } catch (ClientProtocolException e) { 
     e.printStackTrace(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 

    try { 
     BufferedReader reader = new BufferedReader(new InputStreamReader(
       is, "iso-8859-1"), 8); 
     StringBuilder sb = new StringBuilder(); 
     String line = null; 
     while ((line = reader.readLine()) != null) { 
      sb.append(line + "\n"); 
     } 
     is.close(); 
     json = sb.toString(); 
     Log.e("JSON", json); 
    } catch (Exception e) { 
     Log.e("Buffer Error", "Error converting result " + e.toString()); 
    } 

    // try parse the string to a JSON object 
    try { 
     jObj = new JSONObject(json);    
    } catch (JSONException e) { 
     Log.e("JSON Parser", "Error parsing data " + e.toString()); 
    } 

    // return JSON String 
    return jObj; 

} 

}

Answer 1

你在你的主UI線程中執行網絡操作。如果您的目標SDK爲11（Honeycomb）或更高，則會拋出NetworkOnMainThreadException，因爲此行爲可能會阻止用戶界面並導致應用程序無響應。

您必須使用AsyncTask才能避免這種情況，方法是將數據加載到doInBackground(..)方法中。

Answer 2

您正在收到NetworkOnMainThreadException。這意味着網絡操作正在UI線程上完成。這是自API 11以來不允許的。

將網絡操作移至後臺Thread或使用AsyncTask代替。

本教程可以幫助：

http://www.vogella.com/articles/AndroidBackgroundProcessing/article.html