Create a separate Database class android -

i new android.in application need created 4-5 tables. wanted know if can create separate database class , separate class tables? because of code looks clean instead of using

public dbadapter extends sqliteopenhelper{   //all crud operations 4-5 tables in same class  } 

can suggest how make separate initiate db , use crud operations different tables classes?

import java.util.arraylist;  import android.content.contentvalues; import android.content.context; import android.database.cursor; import android.database.sqlite.sqlitedatabase; import android.database.sqlite.sqliteopenhelper; import android.util.log;  public class databasehandler extends sqliteopenhelper {      // static variables     // database version     private static final int database_version = 1;      // 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";     private static final string key_email = "email";     private final arraylist<contact> contact_list = new arraylist<contact>();      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," + key_email + " 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);     }      /**      * crud(create, read, update, delete) operations      */      // adding new contact     public void add_contact(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     values.put(key_email, contact.getemail()); // contact email     // inserting row     db.insert(table_contacts, null, values);     db.close(); // closing database connection     }      // getting single contact     contact get_contact(int id) {     sqlitedatabase db = this.getreadabledatabase();      cursor cursor = db.query(table_contacts, new string[] { key_id,         key_name, key_ph_no, key_email }, key_id + "=?",         new string[] { string.valueof(id) }, null, null, null, null);     if (cursor != null)         cursor.movetofirst();      contact contact = new contact(integer.parseint(cursor.getstring(0)),         cursor.getstring(1), cursor.getstring(2), cursor.getstring(3));     // return contact     cursor.close();     db.close();      return contact;     }      // getting contacts     public arraylist<contact> get_contacts() {     try {         contact_list.clear();          // select query         string selectquery = "select  * " + table_contacts;          sqlitedatabase db = this.getwritabledatabase();         cursor cursor = db.rawquery(selectquery, null);          // looping through rows , adding list         if (cursor.movetofirst()) {         {             contact contact = new contact();             contact.setid(integer.parseint(cursor.getstring(0)));             contact.setname(cursor.getstring(1));             contact.setphonenumber(cursor.getstring(2));             contact.setemail(cursor.getstring(3));             // adding contact list             contact_list.add(contact);         } while (cursor.movetonext());         }          // return contact list         cursor.close();         db.close();         return contact_list;     } catch (exception e) {         // todo: handle exception         log.e("all_contact", "" + e);     }      return contact_list;     }      // updating single contact     public int update_contact(contact contact) {     sqlitedatabase db = this.getwritabledatabase();      contentvalues values = new contentvalues();     values.put(key_name, contact.getname());     values.put(key_ph_no, contact.getphonenumber());     values.put(key_email, contact.getemail());      // updating row     return db.update(table_contacts, values, key_id + " = ?",         new string[] { string.valueof(contact.getid()) });     }      // deleting single contact     public void delete_contact(int id) {     sqlitedatabase db = this.getwritabledatabase();     db.delete(table_contacts, key_id + " = ?",         new string[] { string.valueof(id) });     db.close();     }      // getting contacts count     public int get_total_contacts() {     string countquery = "select  * " + table_contacts;     sqlitedatabase db = this.getreadabledatabase();     cursor cursor = db.rawquery(countquery, null);     cursor.close();      // return count     return cursor.getcount();     }  }