Spring/spring-net
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

SPRNET-1299 - Move older ways of configuring transaction management, using HibernateTemplate, to a 'Classic Spring Usage' section

Browse Source
This commit is contained in:
markpollack
2009-12-16 17:33:31 +00:00
parent 7863d9ede9
commit 4590dfb6d8
4 changed files with 607 additions and 641 deletions
Download Patch File Download Diff File Expand all files Collapse all files

149
doc/reference/src/orm.xml
View File

@@ -591,155 +591,6 @@ public class HibernateCustomerDao : ICustomerDao {
</section>
</section>
<section xml:id="orm-hibernate-template">
<title>The <literal>HibernateTemplate</literal> for Hibernate
1.2</title>
<para>The basic programming model for templating looks as follows for
methods that can be part of any custom data access object or business
service. There are no restrictions on the implementation of the
surrounding object at all, it just needs to provide a Hibernate
<literal>SessionFactory</literal>. It can get the latter from anywhere,
but preferably as an object reference from a Spring IoC container - via
a simple <methodname>SessionFactory</methodname> property setter. The
following snippets show a DAO definition in a Spring container,
referencing the above defined <literal>SessionFactory</literal>, and an
example for a DAO method implementation.</para>
<programlisting language="myxml">&lt;objects&gt;
&lt;object id="CustomerDao" type="Spring.Northwind.Dao.NHibernate.HibernateCustomerDao, Spring.Northwind.Dao.NHibernate"&gt;
&lt;property name="SessionFactory" ref="MySessionFactory"/&gt;
&lt;/object&gt;
&lt;/objects&gt;</programlisting>
<para></para>
<programlisting language="csharp">public class HibernateCustomerDao : ICustomerDao {
private HibernateTemplate hibernateTemplate;
public ISessionFactory SessionFactory
{
set { hibernateTemplate = new HibernateTemplate(value); }
}
public Customer SaveOrUpdate(Customer customer)
{
hibernateTemplate.SaveOrUpdate(customer);
return customer;
}
}</programlisting>
<para>The <literal>HibernateTemplate</literal> class provides many
methods that mirror the methods exposed on the Hibernate
<literal>Session</literal> interface, in addition to a number of
convenience methods such as the one shown above. If you need access to
the <literal>Session</literal> to invoke methods that are not exposed on
the <literal>HibernateTemplate</literal>, you can always drop down to a
callback-based approach like so.</para>
<programlisting language="csharp">public class HibernateCustomerDao : ICustomerDao {
private HibernateTemplate hibernateTemplate;
public ISessionFactory SessionFactory
{
set { hibernateTemplate = new HibernateTemplate(value); }
}
public Customer SaveOrUpdate(Customer customer)
{
return HibernateTemplate.Execute(
delegate(ISession session)
{
// do whatever you want with the session....
session.SaveOrUpdate(customer);
return customer;
}) as Customer;
}
}</programlisting>
<para>Using the anonymous delegate is particularly convenient when you
would otherwise be passing various method parameter calls to the
interface based version of this callback. Furthermore, when using
generics, you can avoid the typecast and write code like the
following</para>
<programlisting language="csharp">IList&lt;Supplier&gt; suppliers = HibernateTemplate.ExecuteFind&lt;Supplier&gt;(
delegate(ISession session)
{
return session.CreateQuery("from Supplier s were s.Code = ?")
.SetParameter(0, code)
.List&lt;Supplier&gt;();
});</programlisting>
<para>where code is a variable in the surrounding block, accessible
inside the anonymous delegate implementation.</para>
<para>A callback implementation effectively can be used for any
Hibernate data access. <literal>HibernateTemplate</literal> will ensure
that <literal>Session</literal> instances are properly opened and
closed, and automatically participate in transactions. The template
instances are thread-safe and reusable, they can thus be kept as
instance variables of the surrounding class. For simple single step
actions like a single Find, Load, SaveOrUpdate, or Delete call,
<literal>HibernateTemplate</literal> offers alternative convenience
methods that can replace such one line callback implementations.
Furthermore, Spring provides a convenient
<literal>HibernateDaoSupport</literal> base class that provides a
<methodname>SessionFactory</methodname> property for receiving a
<literal>SessionFactory</literal> and for use by subclasses. In
combination, this allows for very simple DAO implementations for typical
requirements:</para>
<programlisting language="csharp">public class HibernateCustomerDao : HibernateDaoSupport, ICustomerDao
{
public Customer SaveOrUpdate(Customer customer)
{
HibernateTemplate.SaveOrUpdate(customer);
return customer;
}
}</programlisting>
</section>
<section xml:id="orm-hibernate-daos">
<title>Implementing Spring-based DAOs without HibernateTemplate in
Hibernate 1.2</title>
<para>As an alternative to using Spring's
<literal>HibernateTemplate</literal> to implement DAOs, data access code
can also be written in a more traditional fashion, without wrapping the
Hibernate access code in a callback, while still respecting and
participating in Spring's generic <literal>DataAccessException</literal>
hierarchy. The <literal>HibernateDaoSupport</literal> base class offers
methods to access the current transactional <literal>Session</literal>
and to convert exceptions in such a scenario; similar methods are also
available as static helpers on the
<literal>SessionFactoryUtils</literal> class. Note that such code will
usually pass '<literal>false</literal>' as the value of the
<methodname>DoGetSession(..)</methodname> method's
'<literal>allowCreate</literal>' argument, to enforce running within a
transaction (which avoids the need to close the returned
<literal>Session</literal>, as its lifecycle is managed by the
transaction). Asking for the</para>
<programlisting language="csharp">public class HibernateProductDao : HibernateDaoSupport, IProductDao {
public Customer SaveOrUpdate(Customer customer)
{
ISession session = DoGetSession(false);
session.SaveOrUpdate(customer);
return customer;
}
}
}</programlisting>
<para>This code will <emphasis>not</emphasis> translate the Hibernate
exception to a generic <literal>DataAccessException</literal>.</para>
</section>
<section xml:id="orm-hibernate-tx-declarative">
<title>Declarative transaction demarcation</title>