Caching the results of a method

[Patrick Vanhuyse]

Hi,

I have some business data access and service objects accessing several databases.
These objects are "transactionned" using Spring (TransactionInterceptor, BeanNameAutoProxyCreator).

I want to cache the results of one method of one of the DAO.

How can I do that ?

Here's a summary of my application context :

<?xml version="1.0" encoding="windows-1252"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http&#58;//www.springframework.org/dtd/spring-beans.dtd">

<beans>

  <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="location">
      <value>/prestation.properties</value>
    </property>
  </bean>

  <bean id="messageSource"
        class="org.springframework.context.support.ResourceBundleMessageSource">
    <property name="basename">
      <value>messages</value>
    </property>
  </bean>

  <!-- Datasource & Transaction -->

  <bean id="jotm" class="org.springframework.transaction.jta.JotmFactoryBean"/>

  <bean id="transactionManager" class="org.springframework.transaction.jta.JtaTransactionManager">
    <property name="userTransaction">
      <ref local="jotm"/>
    </property>
  </bean>

  <bean id="dossier.dataSource" class="org.enhydra.jdbc.standard.StandardXADataSource" destroy-method="shutdown">
    <property name="transactionManager">
      <ref local="jotm"/>
    </property>
    <property name="driverName">
      <value>$&#123;dossier.driverClassName&#125;</value>
    </property>
    <property name="url">
      <value>$&#123;dossier.url&#125;</value>
    </property>
    <property name="user">
      <value>$&#123;dossier.username&#125;</value>
    </property>
    <property name="password">
      <value>$&#123;dossier.password&#125;</value>
    </property>
  </bean>

  <bean id="prestation.dataSource" class="org.enhydra.jdbc.standard.StandardXADataSource" destroy-method="shutdown">
    ...
  </bean>

  <bean id="personnel.dataSource" class="org.enhydra.jdbc.standard.StandardXADataSource" destroy-method="shutdown">
    ...
  </bean>

  <bean id="propagationRequiredAttribute"
        class="org.springframework.transaction.interceptor.DefaultTransactionAttribute">
    <property name="propagationBehaviorName">
      <value>PROPAGATION_REQUIRED</value>
    </property>
  </bean>
  <bean id="propagationReadOnlyAttribute"
        class="org.springframework.transaction.interceptor.DefaultTransactionAttribute">
    <property name="propagationBehaviorName">
      <value>PROPAGATION_REQUIRED,readOnly</value>
    </property>
  </bean>

  <bean id="nameTransactionAttributeSource"
        class="org.springframework.transaction.interceptor.NameMatchTransactionAttributeSource">
    <property name="nameMap">
      <map>
        <entry key="ajouter*">
          <ref local="propagationRequiredAttribute"/>
        </entry>
        <entry key="cloturer*">
          <ref local="propagationRequiredAttribute"/>
        </entry>
        <entry key="modifier*">
          <ref local="propagationRequiredAttribute"/>
        </entry>
        <entry key="*">
          <ref local="propagationReadOnlyAttribute"/>
        </entry>
      </map>
    </property>
  </bean>

  <bean id="transactionInterceptor" class="org.springframework.transaction.interceptor.TransactionInterceptor">
    <property name="transactionManager">
      <ref local="transactionManager"/>
    </property>
    <property name="transactionAttributeSource">
      <ref local="nameTransactionAttributeSource"/>
    </property>
  </bean>

  <!-- Proxy -->

  <bean id="auto" class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
    <property name="interceptorNames">
      <list>
        <idref local="transactionInterceptor"/>
      </list>
    </property>
    <property name="beanNames">
      <list>
        <idref local="dossierOAD"/>
        <idref local="dossierService"/>
        ...
      </list>
    </property>
  </bean>

  <!-- Business Object -->

  <bean id="dossierOAD" class="com.greisch.gestion.prestation.oad.JDBCDossier">
    <property name="dataSource">
      <ref local="dossier.dataSource"/>
    </property>
  </bean>
  <bean id="dossierService" class="com.greisch.gestion.prestation.DossierServiceImpl">
    <property name="dossierOAD">
      <ref local="dossierOAD"/>
    </property>
  </bean>

  ...

</beans>

Thanks

[Colin Yates]

I don't think there is any default spring caching functionality, and I don't think there should be as it is such a domain specific problem

If you are using Hibernate then hibernate can cache.

If you want to write your own, then you can either use interceptors to cache results of a single method, or you can do it the "old" way, wrap your DAO in a cachingDAO and cache in a map, i.e.:

  interface MyDAO {
    List<MyObject> getResults&#40;final Object someCriteria&#41;;
  &#125;
  
  final class HibernateMyDAOImpl extends XYZ implements MyDAO &#123;
    public List<MyObject> getResults&#40;final Object someCriteria&#41; &#123;
      return getHibernateTemplate etc....
    &#125;
  &#125;

  final class CachingMyDAOImpl implements MyDAO &#123;
    private final MyDAO delegate;
    private final Cache cache;

    public CachingMyDAOImpl&#40;final MyDAO theDelegate, final Cache theCache&#41; &#123;
      this.delegate = theDelegate;
      this.cache = theCache;
    &#125;

    public List<MyObject> getResults&#40;final Object someCriteria&#41; &#123;
      if &#40;cache.contains&#40;someCriteria&#41;&#41; &#123;
        return cache.get&#40;someCriteria&#41;;
      &#125; else &#123;
        List<MyObject> results = delegate.getResults&#40;someCriteria&#41;;
        cache.put&#40;someCriteria, results&#41;;
        return results;
      &#125;
    &#125;
  &#125;

HTH.

[Patrick Vanhuyse]

There is caching functionality in Spring Modules working like transaction functionality in Spring.
I need some advice to use both at the sime time.

[Colin Yates]

Ah, maybe I should read which forum this is before jumping in and offering my 1.5 cents

[alruiz15]

Patrick,

If you want, send me your code at alruiz15@yahoo.com and I'll take a look.

Alex.