Sqliteデータベースにデータを格納する問題

Question

私はあなたの助けが必要です。 broadcastreceiverを使用し、そのnoを私のデータベースに保存したいのですが、私がそれを示すときは： - ヌルオブジェクト参照で仮想メソッド 'android.content.Context.getResources（）'を呼び出そうとしました。事前に私...ありがとう...

ServiceReceiver.java

public class ServiceReceiver extends BroadcastReceiver { 

MyReceiver receiver = new MyReceiver(); 

@Override 
public void onReceive(final Context context, Intent intent) { 


    TelephonyManager telephony = (TelephonyManager)context.getSystemService(Context.TELEPHONY_SERVICE); 
    telephony.listen(new PhoneStateListener(){ 
     @Override 
     public void onCallStateChanged(int state, String incomingNumber) { 
      super.onCallStateChanged(state, incomingNumber); 


       System.out.println("incomingNumber :" + incomingNumber); 
       receiver.setData(incomingNumber, context); 


     } 
    }, PhoneStateListener.LISTEN_CALL_STATE); 
}} 

DataBaseHelper.java

public class DataBaseHelper extends SQLiteOpenHelper { 

public static final String DATABASE_NAME = "callinfo.db"; 
public static final String TABLE_NAME = "misscall"; 
public static final String COL_1 = "ID"; 
public static final String COL_2 = "MOBILE"; 

public DataBaseHelper(Context context) { 
    super(context, DATABASE_NAME, null, 1); 

    SQLiteDatabase sqLiteDatabase = this.getWritableDatabase(); 
} 

@Override 
public void onCreate(SQLiteDatabase sqLiteDatabase) { 

    sqLiteDatabase.execSQL("create table " + TABLE_NAME +" (ID INTEGER PRIMARY KEY AUTOINCREMENT,MOBILE VARCHAR(20));"); 
} 

@Override 
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) { 

    sqLiteDatabase.execSQL("DROP TABLE IF EXITS"+ TABLE_NAME); 
    onCreate(sqLiteDatabase); 
} 
public boolean insertData(String mobile) { 
    SQLiteDatabase db = this.getWritableDatabase(); 
    ContentValues contentValues = new ContentValues(); 
    contentValues.put(COL_2,mobile); 
    long result = db.insert(TABLE_NAME,null ,contentValues); 
    if(result == -1) 
     return false; 
    else 
     return true; 
}} 

MyReceiver.java

public class MyReceiver extends AppCompatActivity { 

DataBaseHelper myDB; 

public MyReceiver(){ 


} 

public void setData(String incomingNumber, Context context){ 


    myDB = new DataBaseHelper(context);//i think here i get that error 
    Toast.makeText(context, incomingNumber, Toast.LENGTH_LONG).show(); 
    save(incomingNumber,context); 

} 


public void save(String number,Context context){ 

    if(number!=null){ 
     AddData(number); 

    } 

} 

public void AddData(String number) { 

    boolean isInserted = myDB.insertData(number); 

    if(isInserted == true) 
     Toast.makeText(MyReceiver.this, "Data Inserted", Toast.LENGTH_LONG).show(); 

    else 
     Toast.makeText(MyReceiver.this,"Data not Inserted", Toast.LENGTH_LONG).show(); 
} } 

エラー明らか

java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference 
                         at android.content.ContextWrapper.getResources(ContextWrapper.java:90) 
                         at android.view.ContextThemeWrapper.getResources(ContextThemeWrapper.java:74) 
                         at android.support.v7.app.AppCompatActivity.getResources(AppCompatActivity.java:551) 
                         at android.widget.Toast.<init>(Toast.java:122) 
                         at android.widget.Toast.makeText(Toast.java:290) 
                         at com.example.abhijeetsingh.recievecall.MyReceiver.setData(MyReceiver.java:51) 
                         at com.example.abhijeetsingh.recievecall.ServiceReceiver$1.onCallStateChanged(ServiceReceiver.java:37) 
                         at android.telephony.PhoneStateListener$2.handleMessage(PhoneStateListener.java:404) 
                         at android.os.Handler.dispatchMessage(Handler.java:102) 
                         at android.os.Looper.loop(Looper.java:145) 
                         at android.app.ActivityThread.main(ActivityThread.java:5951) 
                         at java.lang.reflect.Method.invoke(Native Method) 
                         at java.lang.reflect.Method.invoke(Method.java:372) 
                         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1388) 
                         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1183) 

Answer 1

、あなたはAppCompatActivityクラスの間違った実装を持っています。 Toast.makeText(MyReceiver.this, "Data Inserted", Toast.LENGTH_LONG).show();

私は意味正しく生成されcontext変数が必要Toast.makeText：

このコードは正しくないポイントがあります。

public class MyReceiver { 

DataBaseHelper myDB; 

public MyReceiver(){ 


} 

public void setData(String incomingNumber, Context context){ 


    myDB = new DataBaseHelper(context);//i think here i get that error 
    Toast.makeText(context, incomingNumber, Toast.LENGTH_LONG).show(); 
    save(incomingNumber,context); 

} 


public void save(String number,Context context){ 

    if(number!=null){ 
     AddData(number, context); 

    } 

} 

public void AddData(String number, Context context) { 

    boolean isInserted = myDB.insertData(number); 

    if(isInserted == true) 
     Toast.makeText(context, "Data Inserted", Toast.LENGTH_LONG).show(); 

    else 
     Toast.makeText(context,"Data not Inserted", Toast.LENGTH_LONG).show(); 
} } 

は正しく、あなたが直接ウィンドウを起動startActivityメソッドを介してで初期化する必要がありActivityクラスを使用します。