HHH-7667 docs
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Strong Liu
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@ -373,13 +373,6 @@
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created. With <command>create-drop</command>, the database schema is dropped when the
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<classname>SessionFactory</classname> is closed explicitly.</entry>
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</row>
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<row>
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<entry>cglib.use_reflection_optimizer</entry>
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<entry><para><literal>true</literal> or <literal>false</literal></para></entry>
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<entry>If enabled, Hibernate uses CGLIB instead of runtime reflection. This is a system-level
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property. Reflection is useful for troubleshooting. Hibernate always requires CGLIB even if you disable the
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optimizer. You cannot set this property in hibernate.cfg.xml.</entry>
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</row>
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</tbody>
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</tgroup>
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</table>
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@ -800,7 +800,7 @@ public class SpaceShip {</programlisting>
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<section xml:id="sp_query" >
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<title>Using stored procedures for querying</title>
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<para>Hibernate3 provides support for queries via stored procedures and
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<para>Hibernate provides support for queries via stored procedures and
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functions. Most of the following documentation is equivalent for both.
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The stored procedure/function must return a resultset as the first
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out-parameter to be able to work with Hibernate. An example of such a
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@ -898,7 +898,7 @@ BEGIN
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<section xml:id="querysql-cud">
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<title>Custom SQL for create, update and delete</title>
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<para>Hibernate3 can use custom SQL for create, update, and delete
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<para>Hibernate can use custom SQL for create, update, and delete
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operations. The SQL can be overridden at the statement level or
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inidividual column level. This section describes statement overrides. For
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columns, see <xref linkend="mapping-column-read-and-write" />. <xref
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@ -357,7 +357,7 @@ public class Flight implements Serializable {
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recommended). You can also specify an interface to use for lazy
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initializing proxies (defaults to the class itself): use
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<literal>proxyClass</literal> on <classname>@Proxy</classname>.
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Hibernate will initially return proxies (Javassist or CGLIB) that
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Hibernate will initially return proxies ( using bytecode provider defined by <literal>hibernate.bytecode.provider</literal>) that
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implement the named interface. The persistent object will load when a
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method of the proxy is invoked. See "Initializing collections and
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proxies" below.</para>
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@ -580,7 +580,7 @@ public class Summary {
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<callout arearefs="class17">
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<para><literal>entity-name</literal> (optional - defaults to the
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class name): Hibernate3 allows a class to be mapped multiple
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class name): Hibernate allows a class to be mapped multiple
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times, potentially to different tables. It also allows entity
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mappings that are represented by Maps or XML at the Java level. In
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these cases, you should provide an explicit arbitrary name for the
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@ -723,7 +723,7 @@ public class Person {
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that the class has no identifier property.</para>
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<para>The <literal>unsaved-value</literal> attribute is almost never
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needed in Hibernate3 and indeed has no corresponding element in
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needed in Hibernate and indeed has no corresponding element in
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annotations.</para>
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<para>You can also declare the identifier as a composite identifier.
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@ -272,7 +272,7 @@
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<note>
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<title>Note</title>
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<para>
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In Hibernate3, although the second requirement is not an absolutely hard
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In Hibernate, although the second requirement is not an absolutely hard
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requirement of Hibernate, it is recommended.
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</para>
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</note>
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@ -670,7 +670,7 @@ hibernate.dialect = org.hibernate.dialect.PostgreSQL82Dialect</programlisting>
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<entry>Optimizes second-level cache operation to minimize writes,
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at the cost of more frequent reads. This setting is most useful
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for clustered caches and, in Hibernate3, is enabled by default for
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for clustered caches and, in Hibernate, is enabled by default for
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clustered cache implementations. <para> <emphasis
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role="strong">e.g.</emphasis> <literal>true|false</literal>
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</para></entry>
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@ -911,7 +911,7 @@ hibernate.dialect = org.hibernate.dialect.PostgreSQL82Dialect</programlisting>
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runtime reflection. This is a System-level property and cannot be
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set in <literal>hibernate.cfg.xml</literal>. Reflection can
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sometimes be useful when troubleshooting. Hibernate always
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requires either CGLIB or javassist even if you turn off the
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requires javassist even if you turn off the
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optimizer.</para><para> <emphasis role="strong">e.g.</emphasis>
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<literal>true</literal> | <literal>false</literal> </para></entry>
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</row>
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@ -919,11 +919,8 @@ hibernate.dialect = org.hibernate.dialect.PostgreSQL82Dialect</programlisting>
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<row>
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<entry><literal>hibernate.bytecode.provider</literal></entry>
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<entry><para>Both javassist or cglib can be used as byte
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manipulation engines; the default is
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<literal>javassist</literal>.</para><para> <emphasis
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role="strong">e.g.</emphasis> <literal>javassist</literal> |
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<literal>cglib</literal> </para></entry>
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<entry><para>At the moment, <literal>javassist</literal> is the only supported bytecode provider.</para><para> <emphasis
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role="strong">e.g.</emphasis> <literal>javassist</literal></para></entry>
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</row>
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</tbody>
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</tgroup>
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@ -256,7 +256,7 @@ session.flush();]]></programlisting>
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database. We will also assume that both <literal>Parent</literal> and <literal>Child</literal> have generated
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identifier properties of type <literal>Long</literal>. Hibernate will use the identifier and
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version/timestamp property value to determine which of the children are new. (See
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<xref linkend="objectstate-saveorupdate"/>.) <emphasis>In Hibernate3, it is no longer necessary to specify
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<xref linkend="objectstate-saveorupdate"/>.) <emphasis>In Hibernate, it is no longer necessary to specify
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an <literal>unsaved-value</literal> explicitly.</emphasis>
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</para>
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@ -3,7 +3,7 @@
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<chapter xml:id="filters" xmlns="http://docbook.org/ns/docbook" >
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<title>Filtering data</title>
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<para>Hibernate3 provides an innovative new approach to handling data with
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<para>Hibernate provides an innovative new approach to handling data with
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"visibility" rules. A <emphasis>Hibernate filter</emphasis> is a global,
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named, parameterized filter that can be enabled or disabled for a particular
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Hibernate session.</para>
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@ -11,7 +11,7 @@
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<section xml:id="objectstate-filters" revision="1">
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<title>Hibernate filters</title>
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<para>Hibernate3 has the ability to pre-define filter criteria and attach
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<para>Hibernate has the ability to pre-define filter criteria and attach
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those filters at both a class level and a collection level. A filter
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criteria allows you to define a restriction clause similar to the existing
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"where" attribute available on the class and various collection elements.
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@ -61,7 +61,7 @@
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<literal>hibernate-mapping</literal>. This allows you to extend a class hierarchy by adding
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a new mapping file. You must specify an <literal>extends</literal> attribute in the subclass mapping,
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naming a previously mapped superclass. Previously this feature made the ordering of the mapping
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documents important. Since Hibernate3, the ordering of mapping files is irrelevant when using the
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documents important. Since Hibernate, the ordering of mapping files is irrelevant when using the
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extends keyword. The ordering inside a single mapping file still needs to be defined as superclasses
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before subclasses.
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</para>
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@ -12,7 +12,7 @@
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over-ridden by a particular HQL or <literal>Criteria</literal>
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query.</para>
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<para>Hibernate3 defines the following fetching strategies:</para>
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<para>Hibernate defines the following fetching strategies:</para>
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<itemizedlist>
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<listitem>
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@ -104,7 +104,7 @@
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<section xml:id="performance-fetching-lazy">
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<title>Working with lazy associations</title>
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<para>By default, Hibernate3 uses lazy select fetching for collections
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<para>By default, Hibernate uses lazy select fetching for collections
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and lazy proxy fetching for single-valued associations. These defaults
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make sense for most associations in the majority of applications.</para>
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@ -144,7 +144,7 @@ Integer accessLevel = (Integer) permissions.get("accounts"); // Error!</program
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<para>On the other hand, you can use join fetching, which is non-lazy by
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nature, instead of select fetching in a particular transaction. We will
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now explain how to customize the fetching strategy. In Hibernate3, the
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now explain how to customize the fetching strategy. In Hibernate, the
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mechanisms for choosing a fetch strategy are identical for single-valued
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associations and collections.</para>
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</section>
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@ -224,9 +224,9 @@ Integer accessLevel = (Integer) permissions.get("accounts"); // Error!</program
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is needed for lazy behavior in single-ended associations. The target
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entity of the association must be proxied. Hibernate implements lazy
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initializing proxies for persistent objects using runtime bytecode
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enhancement which is accessed via the CGLIB library.</para>
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enhancement which is accessed via the bytecode provider.</para>
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<para>At startup, Hibernate3 generates proxies by default for all
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<para>At startup, Hibernate generates proxies by default for all
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persistent classes and uses them to enable lazy fetching of
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<literal>many-to-one</literal> and <literal>one-to-one</literal>
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associations.</para>
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@ -273,7 +273,7 @@ System.out.println(cat==dc); // false</programlisting
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<programlisting role="JAVA">cat.setWeight(11.0); // hit the db to initialize the proxy
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System.out.println( dc.getWeight() ); // 11.0</programlisting>
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<para>Third, you cannot use a CGLIB proxy for a <literal>final</literal>
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<para>Third, you cannot use a bytecode provider generated proxy for a <literal>final</literal>
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class or a class with any <literal>final</literal> methods.</para>
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<para>Finally, if your persistent object acquires any resources upon
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@ -670,7 +670,7 @@ Customer customer = (Customer) session.get( Customer.class, customerId );
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<section xml:id="performance-fetching-lazyproperties">
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<title>Using lazy property fetching</title>
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<para>Hibernate3 supports the lazy fetching of individual properties.
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<para>Hibernate supports the lazy fetching of individual properties.
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This optimization technique is also known as <emphasis>fetch
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groups</emphasis>. Please note that this is mostly a marketing feature;
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optimizing row reads is much more important than optimization of column
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@ -1329,7 +1329,52 @@ hibernate.cache.use_structured_entries true</programlisting>
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<literal>org.hibernate.SessionFactory.evictQueries()</literal>.</para>
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</section>
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</section>
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<section xml:id="bytecode-enhancement" revision="1">
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<title>Bytecode Enhancement</title>
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<para>Hibernate internally needs an entry ( <classname>org.hibernate.engine.spi.EntityEntry</classname> ) to tell
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the current state of an object with respect to its persistent state, when the object is associated with a
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<classname>Session</classname>. However, maintaining this association was kind of heavy operation due to lots of
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other rules must by applied, since 4.2.0, there is a new improvement designed for this purpose, which will reduce
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session-related memory and CPU overloads.
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</para>
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<para>Basically, the idea is, instead of having a customized ( kind of heavy and which was usually identified as hotspot )
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map to do the look up, we change it to </para>
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<programlisting role="JAVA"><![CDATA[EntityEntry entry = (ManagedEntity)entity.$$_hibernate_getEntityEntry();
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]]></programlisting>
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<para>There are three ways to get benefits from this new improvement:</para>
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<section xml:id="entityentry-lookup-impl-interface">
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<title>Implementing <classname>org.hibernate.engine.spi.ManagedEntity</classname> interface</title>
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<para>An entity can choose to implement this interface by itself, then it is the entity's responsibility to maintain
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the bi-association that essentially provides access to information about an instance's association to a
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Session/EntityManager.
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More info about <classname>org.hibernate.engine.spi.ManagedEntity</classname> please find from its javadoc.
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</para>
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</section>
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<section xml:id="entityentry-lookup-impl-interface-by-wrapper">
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<title>Runtime instrument</title>
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<para>Sometimes, you probably don't want to implement an intrusive interface, maybe due to portable concern,
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which is fine and Hibernate will take care of this internally with a wrapper class which implements that interface,
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and also an internal cache that maps this entity instance and the wrapper together.</para>
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<para>Obviously, this is the easiest way to choose, since it doesn't require any change of the project source code,
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but it also cost more memory and CUP usage, comparing to the first one.</para>
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</section>
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<section xml:id="entityentry-lookup-buildtime-instrument">
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<title>Buildtime instrument</title>
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<para>Besides above two approaches, Hibernate also provides you the third choice, which is an ANT task (
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<classname>org.hibernate.tool.enhance.EnhancementTask</classname>) that can be used at build time to
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instrument your entity classes with the required interfaces and methods.
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Meanwhile, the maven and gradle plugin are still under development and will be available soon.
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</para>
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</section>
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</section>
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<section xml:id="performance-collections">
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<title>Understanding Collection performance</title>
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@ -768,7 +768,7 @@ where p.name = some elements(list.names)]]></programlisting>
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Note that these constructs - <literal>size</literal>, <literal>elements</literal>,
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<literal>indices</literal>, <literal>minindex</literal>, <literal>maxindex</literal>,
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<literal>minelement</literal>, <literal>maxelement</literal> - can only be used in
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the where clause in Hibernate3.
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the where clause in Hibernate.
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</para>
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<para>
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@ -9,7 +9,7 @@
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also provides a clean migration path from a direct SQL/JDBC based
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application to Hibernate.</para>
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<para>Hibernate3 allows you to specify handwritten SQL, including stored
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<para>Hibernate allows you to specify handwritten SQL, including stored
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procedures, for all create, update, delete, and load operations.</para>
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<section xml:id="querysql-creating" revision="4">
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@ -800,7 +800,7 @@ public class SpaceShip {</programlisting>
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<section xml:id="sp_query" revision="1">
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<title>Using stored procedures for querying</title>
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<para>Hibernate3 provides support for queries via stored procedures and
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<para>Hibernate provides support for queries via stored procedures and
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functions. Most of the following documentation is equivalent for both.
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The stored procedure/function must return a resultset as the first
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out-parameter to be able to work with Hibernate. An example of such a
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@ -898,7 +898,7 @@ BEGIN
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<section xml:id="querysql-cud">
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<title>Custom SQL for create, update and delete</title>
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<para>Hibernate3 can use custom SQL for create, update, and delete
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<para>Hibernate can use custom SQL for create, update, and delete
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operations. The SQL can be overridden at the statement level or
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inidividual column level. This section describes statement overrides. For
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columns, see <xref linkend="mapping-column-read-and-write" />. <xref
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@ -100,7 +100,6 @@
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<artifactId>slf4j-simple</artifactId>
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</dependency>
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<!-- Hibernate gives you a choice of bytecode providers between cglib and javassist -->
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<dependency>
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<groupId>javassist</groupId>
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<artifactId>javassist</artifactId>
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