JPA 2.0 配置

數據庫：SQLServer 2000 驅動：jtds-1.2.5.jar（http://sourceforge.net/projects/jtds/files/）

爲什麼不用msbase.jar、mssqlserver.jar、msutil.jar？因爲這三個驅動文件有BUG。

JPA 2.0 ：hibernate-jpa-2.0-api-1.0.0.Final.jar

二級緩存：ehcache-core-2.4.2.jar（http://sourceforge.net/projects/ehcache/files/）

① 使用JDBC 配置數據源

WEB-INF\classes\META-INF\persistence.xml

<persistence-unit name="JPATest" transaction-type="RESOURCE_LOCAL">
          <provider>org.hibernate.ejb.HibernatePersistence</provider>
          <shared-cache-mode>DISABLE_SELECTIVE</shared-cache-mode>
          <properties>
                   <property name="javax.persistence.jdbc.driver" value="net.sourceforge.jtds.jdbc.Driver"/>
                   <property name="javax.persistence.jdbc.url" value="jdbc:jtds:sqlserver://localhost:1433;DatabaseName=demo"/>
                   <property name="javax.persistence.jdbc.user" value="sa"/>
                   <property name="javax.persistence.jdbc.password" value="joe"/>

                   <property name="hibernate.dialect" value="org.hibernate.dialect.SQLServerDialect" />
                   <property name="hibernate.show_sql" value="true" />
                   <property name="hibernate.format_sql" value="false" />

② 使用Tomcat 的數據源

● WEB-INF\classes\META-INF\persistence.xml

<persistence-unit name="JPATest" transaction-type="RESOURCE_LOCAL">
           <provider>org.hibernate.ejb.HibernatePersistence</provider>
           <non-jta-data-source>java:comp/env/jdbc/ticket</non-jta-data-source>
           <shared-cache-mode>DISABLE_SELECTIVE</shared-cache-mode>
           <properties>
                   <property name="hibernate.dialect" value="org.hibernate.dialect.SQLServerDialect" />
                   <property name="hibernate.show_sql" value="true" />
                   <property name="hibernate.format_sql" value="false" />

● tomcat\config\server.xml

● tomcat\config\context.xml

③ 使用JBOSS的數據源

● WEB-INF\classes\META-INF\persistence.xml

<persistence-unit name="JPATest" transaction-type="RESOURCE_LOCAL">
           <provider>org.hibernate.ejb.HibernatePersistence</provider>
           <non-jta-data-source>java:/etix_app</non-jta-data-source>
           <shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode>
           <properties>
                   <property name="hibernate.dialect" value="org.hibernate.dialect.SQLServerDialect" />
                   <property name="hibernate.show_sql" value="true" />
                   <property name="hibernate.format_sql" value="false" />

● jboss-6.0.0.Final\server\default\deploy\mssql-ds.xml（在 jboss-6.0.0.Final\docs\examples\jca\ 目錄下可以找到 mssql-ds.xml 模板）

<?xml version="1.0" encoding="UTF-8"?>
<datasources>
           <local-tx-datasource>
           <jndi-name>etix_app</jndi-name>
           <connection-url>jdbc:jtds:sqlserver://localhost:1433;DatabaseName=demo</connection-url>
           <driver-class>net.sourceforge.jtds.jdbc.Driver</driver-class>
           <user-name>sa</user-name>
           <password>joe</password>
           <metadata>
                       <type-mapping>MS SQLSERVER2000</type-mapping>
           </metadata>
           </local-tx-datasource>
</datasources>

④ 配置二級緩存

● WEB-INF\classes\ehcache.xml

</ehcache>

● Static Configuration of the Cache

Caching can be configured at the level of the global persistence unit or on a per-class basis. It is achieved through a combination of a persistence unit setting and class settings.

The persistence unit cache setting is controlled by the shared-cache-mode element in the persistence.xml file.

It has five options:

① <shared-cache-mode>NOT_SPECIFIED</shared-cache-mode>
when the shared cache setting is not explicitly specified in the persistence.xml file or by the presence of the javax.persistence.sharedCache.mode property, it is up to the provider to either cache or not cache, depending upon its own defaults and inclinations.

② <shared-cache-mode>ALL</shared-cache-mode>
the shared cache to be completely enabled

③ <shared-cache-mode>NONE</shared-cache-mode>
the shared cache to be completely disabled

④ <shared-cache-mode>DISABLE_SELECTIVE</shared-cache-mode>
the default behavior to cache every entity in the persistence unit.then annotating the specific entity class that is to remain uncached with @Cacheable(false)

for exsample:

@Entity
@Table(name="student")
@Cacheable(false)
public class Student implements Serializable {

⑤ <shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode>
meaning that the default is to disable caching for all entities except those that have been annotated with @Cacheable(true) (or just @Cacheable because the default value of @Cacheable is true)

for example:@Entity
@Table(name="student")
@Cacheable
public class Student implements Serializable {

● JPA Cache