com.erudika.para.persistence

Interface DAO

All Known Implementing Classes:

MockDAO

public interface DAO

The core persistence interface. Stores and retrieves domain objects to/from a data store.

Author:

Alex Bogdanovski [alex@erudika.com]

Method Summary

Modifier and Type	Method and Description
<P extends ParaObject> String	create(P object) Persists an object to the data store.
<P extends ParaObject> String	create(String appid, P object) Persists an object to the data store.
<P extends ParaObject> void	createAll(List<P> objects) Saves multiple objects to the data store.
<P extends ParaObject> void	createAll(String appid, List<P> objects) Saves multiple objects to the data store.
<P extends ParaObject> void	delete(P object) Deletes an object permanently.
<P extends ParaObject> void	delete(String appid, P object) Deletes an object permanently.
<P extends ParaObject> void	deleteAll(List<P> objects) Deletes multiple objects.
<P extends ParaObject> void	deleteAll(String appid, List<P> objects) Deletes multiple objects.
<P extends ParaObject> P	read(String key) Retrieves an object from the data store.
<P extends ParaObject> P	read(String appid, String key) Retrieves an object from the data store.
<P extends ParaObject> Map<String,P>	readAll(List<String> keys, boolean getAllColumns) Retrieves multiple objects from the data store.
<P extends ParaObject> Map<String,P>	readAll(String appid, List<String> keys, boolean getAllColumns) Retrieves multiple objects from the data store.
<P extends ParaObject> List<P>	readPage(Pager pager) Reads a fixed number of objects.
<P extends ParaObject> List<P>	readPage(String appid, Pager pager) Reads a fixed number of objects.
<P extends ParaObject> void	update(P object) Updates an object permanently.
<P extends ParaObject> void	update(String appid, P object) Updates an object permanently.
<P extends ParaObject> void	updateAll(List<P> objects) Updates multiple objects.
<P extends ParaObject> void	updateAll(String appid, List<P> objects) Updates multiple objects.

Method Detail

create

<P extends ParaObject> String create(String appid,
                                     P object)

Persists an object to the data store.

Type Parameters:

P - the type of object

Parameters:

appid - name of the App

object - the domain object

Returns:

the object's id or null if not created.

create

<P extends ParaObject> String create(P object)

Persists an object to the data store.

Type Parameters:

P - the type of object

Parameters:

object - the domain object

Returns:

the object's id or null if not created.

read

<P extends ParaObject> P read(String appid,
                              String key)

Retrieves an object from the data store.

Type Parameters:

P - the type of object

Parameters:

appid - name of the App

key - an object id

Returns:

the object or null if not found

read

<P extends ParaObject> P read(String key)

Retrieves an object from the data store.

Type Parameters:

P - the type of object

Parameters:

key - an object id

Returns:

the object or null if not found

update

<P extends ParaObject> void update(String appid,
                                   P object)

Updates an object permanently.

Type Parameters:

P - the type of object

Parameters:

appid - name of the App

object - the domain object

update

<P extends ParaObject> void update(P object)

Updates an object permanently.

Type Parameters:

P - the type of object

Parameters:

object - the domain object

delete

<P extends ParaObject> void delete(String appid,
                                   P object)

Deletes an object permanently.

Type Parameters:

P - the type of object

Parameters:

appid - name of the App

object - the domain object

delete

<P extends ParaObject> void delete(P object)

Deletes an object permanently.

Type Parameters:

P - the type of object

Parameters:

object - the domain object

createAll

<P extends ParaObject> void createAll(String appid,
                                      List<P> objects)

Saves multiple objects to the data store.

Type Parameters:

P - the type of object

Parameters:

appid - name of the App

objects - the list of objects to save

createAll

<P extends ParaObject> void createAll(List<P> objects)

Saves multiple objects to the data store.

Type Parameters:

P - the type of object

Parameters:

objects - the list of objects to save

readAll

<P extends ParaObject> Map<String,P> readAll(String appid,
                                             List<String> keys,
                                             boolean getAllColumns)

Retrieves multiple objects from the data store.

Type Parameters:

P - the type of object

Parameters:

appid - name of the App

keys - a list of object ids

getAllColumns - true if all columns must be retrieved. used to save bandwidth.

Returns:

a map of ids to objects

readAll

<P extends ParaObject> Map<String,P> readAll(List<String> keys,
                                             boolean getAllColumns)

Retrieves multiple objects from the data store.

Type Parameters:

P - the type of object

Parameters:

keys - a list of object ids

getAllColumns - true if all columns must be retrieved. used to save bandwidth.

Returns:

a map of ids to objects

readPage

<P extends ParaObject> List<P> readPage(String appid,
                                        Pager pager)

Reads a fixed number of objects. Used for scanning a data store page by page. Calling this method would bypass the read cache and will hit the DB.

Type Parameters:

P - the type of object

Parameters:

appid - name of the App

pager - a Pager

Returns:

a list of objects

readPage

<P extends ParaObject> List<P> readPage(Pager pager)

Reads a fixed number of objects. Used for scanning a data store page by page. Calling this method would bypass the read cache and will hit the DB.

Type Parameters:

P - the type of object

Parameters:

pager - a Pager

Returns:

a list of objects

updateAll

<P extends ParaObject> void updateAll(String appid,
                                      List<P> objects)

Updates multiple objects.

Type Parameters:

P - the type of object

Parameters:

appid - name of the App

objects - a list of objects to update

updateAll

<P extends ParaObject> void updateAll(List<P> objects)

Updates multiple objects.

Type Parameters:

P - the type of object

Parameters:

objects - a list of objects to update

deleteAll

<P extends ParaObject> void deleteAll(String appid,
                                      List<P> objects)

Deletes multiple objects.

Type Parameters:

P - the type of object

Parameters:

appid - name of the App

objects - a list of objects to delete

deleteAll

<P extends ParaObject> void deleteAll(List<P> objects)

Deletes multiple objects.

Type Parameters:

P - the type of object

Parameters:

objects - a list of objects to delete