What is the purpose of FeedReaderContract and how to define inner class in OpenHelper Class [closed]

Answer 1

I understand as:

public static class FeedReaderContract{

    // Prevents the FeedReaderContract class from being instantiated.
    private FeedReaderContract() {} 

    //The FeedEntry table definition
    public static abstract class FeedEntry implements BaseColumns {
        public static final String TABLE_NAME = "entry";
        public static final String COLUMN_NAME_ENTRY_ID = "entryid";
        public static final String COLUMN_NAME_TITLE = "title";
        public static final String COLUMN_NAME_SUBTITLE = "subtitle";
        ...
    }

    //more tables definition
}

So you can't instatiate the contract but can access all the inner classes Constants. Like the example line:

private static final String SQL_CREATE_ENTRIES =
"CREATE TABLE " + FeedReaderContract.FeedEntry.TABLE_NAME + " (" +
FeedReaderContract.FeedEntry._ID + " INTEGER PRIMARY KEY," //continues

Access the FeedEntry constants (TABLE_NAME and _ID) of the inner class in FeedReaderContract class.

Hope it helps.