I have an application running on tomcat where we have multiple wars.
We use hibernate/jpa and spring. The classes are annotated and we don't have a persistence.xml for any of them. All configuration is in the spring context file and the annotations. Here's the spring file:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:flow="http://www.springframework.org/schema/webflow-config"
xmlns:lang="http://www.springframework.org/schema/lang"
xmlns:osgi="http://www.springframework.org/schema/osgi"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:util="http://www.springframework.org/schema/util"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:cache="http://www.springframework.org/schema/cache"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/webflow-config http://www.springframework.org/schema/webflow-config/spring-webflow-config-2.0.xsd
http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-3.0.xsd
http://www.springframework.org/schema/osgi http://www.springframework.org/schema/osgi/spring-osgi-3.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd
http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa.xsd
http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache.xsd
">
<tx:annotation-driven transaction-manager="transactionManager"/>
<!-- Directory to scan for repository classes -->
<jpa:repositories
base-package="com.blah.db.model.repository" />
<bean id="propertyConfigurer"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>/WEB-INF/configuration.properties</value>
</list>
</property>
</bean>
<cache:annotation-driven />
<bean id="cacheManager" class="org.springframework.cache.ehcache.EhCacheCacheManager" p:cache-manager-ref="ehcache"/>
<bean id="ehcache" class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean"
p:config-location="/WEB-INF/ehcache.xml"
p:shared="true"/>
<context:component-scan base-package="com.blah.db.model.service" />
<context:component-scan base-package="com.blah.business.objects" />
<context:component-scan base-package="com.blah.data.access.objects" />
<context:component-scan base-package="com.blah.common" />
<bean class="org.springframework.orm.jpa.JpaTransactionManager"
id="transactionManager">
<property name="entityManagerFactory"
ref="entityManagerFactory" />
<property name="jpaDialect">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" />
</property>
</bean>
<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="packagesToScan" value="com.blah.db.model" />
<property name="dataSource" ref="dataSource" />
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="generateDdl" value="${hibernate.generate.ddl}" />
<property name="database" value="${hibernate.database}" />
<property name="showSql" value="${show.sql}" />
</bean>
</property>
<property name="jpaProperties">
<map>
<entry key="hibernate.default_schema" value="${default.schema}"/>
<entry key="hibernate.dialect" value="${jdbc.hibernate.dialect}"/>
<entry key="hibernate.id.new_generator_mappings" value="${new.generator.mappings}"/>
<entry key="hibernate.cache.region.factory_class" value="${hibernate.cache.factory.class}"/>
<entry key="hibernate.cache.use_second_level_cache" value="${hibernate.use.second.level.cache}"/>
<entry key="hibernate.cache.use_query_cache" value="${hibernate.use.query.cache}"/>
<entry key="net.sf.ehcache.configurationResourceName" value="${ehcache.config.file}"/>
</map>
</property>
</bean>
<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName" value="org.postgresql.Driver" />
<property name="url" value="jdbc:postgresql://127.0.0.1:5432/blah" />
<property name="username" value="postgres" />
<property name="password" value="password" />
</bean>
<bean id="openSessionInViewInterceptor" class="org.springframework.orm.jpa.support.OpenEntityManagerInViewInterceptor">
<property name="entityManagerFactory">
<ref local="entityManagerFactory"/>
</property>
<property name="jpaProperties">
<map>
<entry key="singleSession" value="true"/>
<entry key="flushModeName" value="FLUSH_AUTO"/>
</map>
</property>
</bean>
</beans>
How do I ensure that all the wars use a single persistence unit? I want to be able to use ehcache, but I know I can't use it if they all use their own PU.
Is my only option moving to JavaEE and packaging it all in an EAR?
Thanks!
Sharing a persistance unit between applications means deploying your common classes in the shared tomcat folder, which is as safe as cleaning a loaded shotgun with your tonge.
If you need to share a cache, with ehcache, use terracotta as an off heap cache. This solution will be simples and definitely less risky.
Another option is to merge those 4 apps into a bigger app, which might make sense if all of them share the same data.