java.lang.ClassCastException: android.app.Application - литье

Question

java.lang.ClassCastException: android.app.Application не может быть приведен к com.example.project.DataDevice

Мой код:

public class Project extends Activity{ 

private boolean connection = false; 
public Tag tagFromIntent = null; 

private Button textRead; 
private NFCForegroundUtil nfcForegroundUtil; 



@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.project);  

    nfcForegroundUtil = new NFCForegroundUtil(this); 

    this.textRead= (Button) findViewById(R.id.button2); 

    initListeners(); 
} 


private void initListeners() { 


    textRead.setOnClickListener(new OnClickListener() 
    { 

     public void onClick(View v) 
     { 

      if (connection == true) 
      { 
       DataDevice dataDevice = (DataDevice) getApplication(); 
       dataDevice.setCurrentTag(tagFromIntent); 

       IsoDep nfca = IsoDep.get(dataDevice.getCurrentTag()); 

       try 
       { 
        byte[] read= new byte[] { 0x00}; 

        byte[] ans = null; 

        nfca.setTimeout(2000); 
        nfca.connect(); 
        nfca.setTimeout(2000); 
        if (nfca.isConnected()) 
        { 

         nfca.setTimeout(2000); 
         ans = nfca.transceive(read); 

         try 
         { 
          Thread.sleep(1500); 
         } 
         catch (InterruptedException e) 
         { 
          e.printStackTrace(); 
         } 

        } 

        nfca.close(); 
        String textRead = HexBin.encode(ans); 

       } 

       catch (IOException e) 
       { 
        Log.i("A", "IOException is: " + e.getMessage()); 
        e.printStackTrace(); 
       } 

       if (nfca.isConnected()) 
       { 
        try 
        { 
         nfca.close(); 
        } 
        catch (IOException e) 
        { 
         e.printStackTrace(); 
        } 
       } 

      } 

     } 
    }); 


} 

@Override 
protected void onNewIntent(Intent intent) 
{ 

    super.onNewIntent(intent); 
    action = intent.getAction(); 
    tagFromIntent = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG); 
    connection = true; 

} 

public void onPause() 
{ 
    super.onPause(); 
    nfcForegroundUtil.disableForeground(); 
} 

public void onResume() 
{ 
    super.onResume(); 

    nfcForegroundUtil.enableForeground(); 

    if (!nfcForegroundUtil.getNfc().isEnabled()) 
    { 
     Toast.makeText(
       getApplicationContext(), 
       "Please activate NFC and press Back to return to the application!", 
       Toast.LENGTH_LONG).show(); 
     startActivity(new Intent(
       android.provider.Settings.ACTION_WIRELESS_SETTINGS)); 
    } 
} 
} 

Мой манифест код:

<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.example.project" 
android:versionCode="1" 
android:versionName="1.0" > 

<uses-sdk 
    android:minSdkVersion="8" 
    android:targetSdkVersion="15" /> 

<uses-permission android:name="android.permission.NFC" /> 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 

<uses-feature 
    android:name="android.hardware.nfc" 
    android:required="true" /> 

<application 
    android:icon="@drawable/ic_launcher" 
    android:label="@string/app_name" 
    android:theme="@style/AppTheme" 
    android:name="android.app.Application"> 
    <activity 
     android:name=".StartActivity" 
     android:label="@string/title_activity_main" > 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 
      <category android:name="android.intent.category.DEFAULT" /> 
      <action android:name="android.nfc.action.TECH_DISCOVERED" /> 
      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 

    <activity 
     android:screenOrientation="portrait" 
     android:name=".Project" 
     android:label="@string/title_activity_main" /> 

</application> 

Моя ошибка:

FATAL EXCEPTION: main 
java.lang.ClassCastException: android.app.Application cannot be cast to com.example.Project.DataDevice 
at com.example.project.Project$1.onClick(Project.java:67) 
at android.view.View.performClick(View.java:3511) 
at android.view.View$PerformClick.run(View.java:14105) 
at android.os.Handler.handleCallback(Handler.java:605) 
at android.os.Handler.dispatchMessage(Handler.java:92) 
at android.os.Looper.loop(Looper.java:137) 
at android.app.ActivityThread.main(ActivityThread.java:4424) 
at java.lang.reflect.Method.invokeNative(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:511) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
at dalvik.system.NativeStart.main(Native Method) 

DataDevice класс:

public class DataDevice extends Application 
{ 
    private Tag currentTag; 

    public void setCurrentTag(Tag currentTag) { 
     this.currentTag = currentTag; 
    } 

    public Tag getCurrentTag() { 
     return currentTag; 
    } 

    //(...) 
} 

Я искал ответ на StackOverflow, ничего не помогало. Кто-нибудь знает, что происходит? DataDevice и NFCUtilForeground работают хорошо (в других приложениях).

Answer 1

Атрибут android:name в теге application в вашем файле манифеста должен указывать на ваш класс DataDevice. Нравится:

<application 
android:icon="@drawable/ic_launcher" 
android:label="@string/app_name" 
android:theme="@style/AppTheme" 
android:name="your.package.DataDevice"> 

......... 
.......... 
</application>