org.mentabean
Interface BeanSession

All Known Implementing Classes:

H2BeanSession, JdbcBeanSession, MySQLBeanSession, OracleBeanSession

public interface BeanSession

Describe a simple ORM interface that can perform CRUD for Beans according to properties defined programmatically on BeanManager. It can also load lists and unique beans based on properties set on a given bean. It also supports dynamic update, in other words, it will only update fields from a bean loaded from the database that were actually modified during the session. The behavior can be turned off when necessary ,in other words, when you want to blindly update all properties from a bean in the database regarding of whether they were modified or not.

Author:

Sergio Oliveira Jr.

Method Summary

int	countList(Object bean) Count the number of beans that would be returned by a loadList method.
boolean	delete(Object bean) Delete the bean from the database.
void	insert(Object bean) Insert the bean in the database.
boolean	load(Object bean) Load the bean from the database, injecting all its properties through reflection.
<E> List<E>	loadList(E bean) Load a list of beans based on the properties present in the bean passed.
<E> List<E>	loadList(E bean, int limit) Same as loadList(bean) except that you can limit the number of beans returned in the list.
<E> List<E>	loadList(E bean, String orderBy) Same as loadList(bean) except that you can order the list returned by passing an SQL orderBy clause.
<E> List<E>	loadList(E bean, String orderBy, int limit) Same as loadList(bean) except that you can limit the number of beans returned in the list as well as sort them by passing a orderBy SQL clause.
<E> E	loadUnique(E bean) Same as loadList(bean) but it attempts to load a single bean only.
int	update(Object bean) Update the bean in the database.
int	updateAll(Object bean) Same as update(bean) but here you can turn off the default dynamic update behavior and force all bean properties to be updated regardless whether they have been modified or not.

Method Detail

load

boolean load(Object bean)

Load the bean from the database, injecting all its properties through reflection. Note that the bean passed MUST have its primary key set otherwise there is no way we can load it from the database.

Parameters:

bean - The bean we want to load from the DB.

Returns:

true if the bean was found in the database, false otherwise

update

int update(Object bean)

Update the bean in the database. Only the bean fields that have been modified (dirty) will be updated. It will return 1 if an update did happen or 0 if the bean could not be found in the database or if there was nothing modified in bean. The bean MUST have its primary key set, otherwise it is impossible to update the bean in the database, and an exception will be thrown.

Parameters:

bean - The bean to be updated

Returns:

1 if update was successful, 0 if the update did not happen or was not necessary

updateAll

int updateAll(Object bean)

Same as update(bean) but here you can turn off the default dynamic update behavior and force all bean properties to be updated regardless whether they have been modified or not.

Parameters:

bean -

Returns:

the number of rows that were updated

Throws:

Exception

insert

void insert(Object bean)

Insert the bean in the database. Depending on the type of PK, the generation of the PK can and should be taken care by the DB itself. The generated PK should be inserted in the bean by reflection, before the method returns. The default, database-independent implementation of this method, insert all fields in the database not worrying about PK generation strategies.

Parameters:

bean - The bean to insert

delete

boolean delete(Object bean)

Delete the bean from the database. The PK of the bean MUST be set. The bean can only be deleted by its PK.

Parameters:

bean -

Returns:

true if it was deleted or false if it did not exist

Throws:

Exception

countList

int countList(Object bean)

Count the number of beans that would be returned by a loadList method.

Parameters:

bean - The bean holding the properties used by the list query.

Returns:

the number of beans found in the database

loadList

<E> List<E> loadList(E bean)

Load a list of beans based on the properties present in the bean passed. For example, if you want to load all users with lastName equal to 'saoj' you would instantiate a bean and set its lastName property to 'saoj' before passing it as an argument to this method.

Type Parameters:

E -

Parameters:

bean - The bean holding the properties used by the list query.

Returns:

A list of beans the match the properties in the given bean. Or an empty list if nothing was found.

loadList

<E> List<E> loadList(E bean,
                     String orderBy)

Same as loadList(bean) except that you can order the list returned by passing an SQL orderBy clause.

Type Parameters:

E -

Parameters:

bean - The bean holding the properties used by the list query.

orderBy - The orderBy SQL clause.

Returns:

A list of beans the match the properties in the given bean. Or an empty list if nothing was found.

loadList

<E> List<E> loadList(E bean,
                     int limit)

Same as loadList(bean) except that you can limit the number of beans returned in the list.

Type Parameters:

E -

Parameters:

bean - The bean holding the properties used by the list query.

limit - The max number of beans returned in the list.

Returns:

A list of beans the match the properties in the given bean. Or an empty list if nothing was found.

loadList

<E> List<E> loadList(E bean,
                     String orderBy,
                     int limit)

Same as loadList(bean) except that you can limit the number of beans returned in the list as well as sort them by passing a orderBy SQL clause.

Type Parameters:

E -

Parameters:

bean - The bean holding the properties used by the list query.

orderBy - The orderBy SQL clause.

limit - The max number of beans returned in the list.

Returns:

A list of beans the match the properties in the given bean. Or an empty list if nothing was found.

loadUnique

<E> E loadUnique(E bean)

Same as loadList(bean) but it attempts to load a single bean only. If more than one bean is found it throws an exception.

Type Parameters:

E -

Parameters:

bean - The bean holding the properties used by the load query.

Returns:

A unique bean that match the properties in the given bean. Or null if nothing was found.

Throws:

BeanException - if more than one bean is found by the query.