在将数据从URL添加到android中的SQLite数据库时，记录在10点之后重复

Question

I was trying to add some fields from URL to SQLite Database.Here I am facing a problem like after adding 10 records the records are adding from the beginning. I am doing in getView() method of the CustomAdapter. Suggest me any solution or guide me if the way I am doing is wrong.

Here is my DatabaseHandler class

public class DatabaseHandler extends SQLiteOpenHelper {
// All Static variables
// Database Version
private static final int DATABASE_VERSION = 2;

// Database Name
private static final String DATABASE_NAME = "contactsManager";

// Contacts table name
private static final String TABLE_CONTACTS = "contacts";

// Contacts Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_PH_NO = "phone_number";

public DatabaseHandler(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
    String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("
            + KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
            + KEY_PH_NO + " TEXT" + ")";
    db.execSQL(CREATE_CONTACTS_TABLE);
}

// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // Drop older table if existed
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS);

    // Create tables again
    onCreate(db);
}

/**
 * All CRUD(Create, Read, Update, Delete) Operations
 */

// Adding new contact
void addContact(Contact contact) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(KEY_NAME, contact.getName()); // Contact Name
    values.put(KEY_PH_NO, contact.getPhoneNumber()); // Contact Phone

    // Inserting Row
    db.insert(TABLE_CONTACTS, null, values);
    db.close(); // Closing database connection
}


// Getting All Contacts
public List<Contact> getAllContacts() {
    List<Contact> contactList = new ArrayList<Contact>();
    // Select All Query
    String selectQuery = "SELECT  * FROM " + TABLE_CONTACTS;

    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = db.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (cursor.moveToFirst()) {
        do {
            Contact contact = new Contact();
            contact.setID(Integer.parseInt(cursor.getString(0)));
            contact.setName(cursor.getString(1));
            contact.setPhoneNumber(cursor.getString(2));
            // Adding contact to list
            contactList.add(contact);
        } while (cursor.moveToNext());
    }

    // return contact list
    return contactList;
}

and the getView() method of my Adapter class is.

public View getView(int i, View view, ViewGroup viewGroup) {
    view = inflater.inflate(R.layout.single_item,null);
    TextView tvName = (TextView)view.findViewById(R.id.txtName);
    TextView tvMobile = (TextView)view.findViewById(R.id.txtPhone);
    DatabaseHandler db = new DatabaseHandler(activity);
    db.addContact(new Contact(dataList.get(i).getName(),dataList.get(i).getPhoneNumber()));
    List<Contact> contacts = db.getAllContacts();
    Log.d("contacts",contacts.get(i).getName()+"");
    tvName.setText(contacts.get(i).getName());
    tvMobile.setText(contacts.get(i).getPhoneNumber());
    return view;
}

the logcat response is like

The actual data contains 14 records but last 4 are not coming

Answer 1

The getView method is a method that is called when the screen needs to be rendered. So getView method can be called more than once. For this reason, you should do database operations outside of this method.

For example in your activity class:

    ...
    contactListView (ListView)findViewById(R.id.lv_contacts_container);<-- your xml
    contactList = db.getAllContacts();
    adapter = new ContactListViewAdapter(this, contactList);
    contactListView.setAdapter(adapter);

    contactListView.setOnItemClickListener(new 
    AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                                int position, long id) {

            //Selected contact entity
            ContactEntity entity = adapter.getData().get(position);
            ...
        }

    });

and simply your adapter class might be like:

public class ContactListViewAdapter extends BaseAdapter {

Context context;
LayoutInflater inflater;
private List<ContactEntity> contactList;

public ContactListViewAdapter(Context context, List<ContactEntity> contactList) {
    this.context = context;
    this.contactList = new ArrayList<>();
    this.contactList.addAll(contactList);
}

@Override
public int getCount() {
    return contactList.size();
}

public List<ContactEntity> getData() {
    return this.contactList;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ContactRowViewHolder holder;
    if (convertView == null) {
        inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = inflater.inflate(R.layout.contact_list_row, parent, false); <--your row xml
        holder = new ContactRowViewHolder();
        holder.contactNameTextView = (TextView) convertView.findViewById(R.id.contact_text); <-- your text view in row 
        convertView.setTag(holder);
    } else {
        holder = (ContactRowViewHolder) convertView.getTag();
    }

    ContactEntity contact = contactList.get(position);
    if (contact == null || contact.getContactName() == null) {
        // error log
    }
    holder.contactNameTextView.setText(contact.getContactName());
    return convertView;
}

static class ContactRowViewHolder {
    private TextView contactNameTextView;
}
}

Note: The holder pattern is good for long lists