I have a database handler that I accidently made an activity and I deleted the code to just make it like a java class but I noticed in my manifest file it says 

'com.something.MyDBHandler' has no default constructor less... (Ctrl+F1) 
Validates resource references inside Android XML files.
 'com.something.MyDBHandler' is not assignable to 'android.app.Activity' less... (Ctrl+F1) 
Validates resource references inside Android XML files.

when I hover over "MyDBHandler" (sixth line from bottom).

and also I get 

Unresolved class 'HighScore' less... (Ctrl+F1) 
Validates resource references inside Android XML files.

when I hover over ".HighScore" (fourth line from bottom).

Manifest

```
<application
    android:allowBackup="true"
    android:icon="@mipmap/gamebutton"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <activity android:name=".GameScreen"
        android:label="@string/app_name" />

    <activity android:name="MyDBHandler" />

    <activity android:name=".HighScore"></activity>
</application>

```

MyDBHandler class

```
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class MyDBHandler extends SQLiteOpenHelper {

private static final int DATABASE_VERSION = 2;
private static final String DATABASE_NAME = "products.db";
public static final String TABLE_PRODUCTS = "products";
public static final String COLUMN_ID = "_id";
public static final String COLUMN_PRODUCTNAME = "productname";

public MyDBHandler(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
    super(context, DATABASE_NAME, factory, DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
    String query = "CREATE TABLE " + TABLE_PRODUCTS + "(" +
            COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
            COLUMN_PRODUCTNAME + " TEXT " +
            ");";
    db.execSQL(query);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_PRODUCTS);
    onCreate(db);
}

//add a new row to the database
public void addProduct(Products product){
    ContentValues values = new ContentValues();
    values.put(COLUMN_PRODUCTNAME, product.get_productname());
    SQLiteDatabase db = getWritableDatabase();
    db.insert(TABLE_PRODUCTS, null, values);
    db.close();
}

/*//delete a product from the database
public void deleteProduct(String productName){
    SQLiteDatabase db = getWritableDatabase();
    db.execSQL("DELETE FROM " + TABLE_PRODUCTS + " WHERE " + COLUMN_PRODUCTNAME + "=\"" + productName + "\";" );
}
*/

//print out the database as a string
public String databaseToString(){
    String dbString = "";
    SQLiteDatabase db = getWritableDatabase();
    String query = "SELECT * FROM " + TABLE_PRODUCTS + " WHERE 1";

    //Cursor point to location in your results

    Cursor c = db.rawQuery(query, null);
    //Move to the first row in your results
    c.moveToFirst();

    while(!c.isAfterLast()){
        if(c.getString(c.getColumnIndex("productname")) != null){
            dbString += c.getString(c.getColumnIndex("productname"));
            dbString += "\n";
        }
        c.moveToNext();
    }

    db.close();
    return dbString;

}

}

```