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Problem with Spring autowiring within a Service Task

Question asked by gaston on Nov 18, 2012
Latest reply on Jul 23, 2013 by wsalembi
Hi all,
I'm having problems calling a Spring autowired Repository from a task. The idea is to have the Service Task call one of the methods of a Service. Problem is, after executing the service task, I'm getting an "Unknown property in expression" if using a delegateExpression (similar to what's mentioned in this other thread), or a null pointer exception, as a result of the @Autowired Repository in myService not being properly instantiated).

The Service Task is being run as
 
   activiti:delegateExpression="${myBeanServiceImpl}")

My service bean is as follows:

   @Service("myBeanServiceImpl")
   public class MyBeanServiceImpl implements JavaDelegate {

      @Autowired
      private TestServiceDummy serviceDummy;

      @Override
      public void execute(DelegateExecution execution) {
         serviceDummy.save(new User()); // <– NPE here, the userRepository is null when called. ie: not being properly autowired.
           }

   // Getters and Setters for the testServiceDummy omitted for brevity

   }



Here's my TestServiceDummyImpl:


   @Service(value="testServiceDummyImpl")
   @Transactional(readOnly = true)
   public class TestServiceDummyImpl implements TestServiceDymmy {
      
      @Autowired
      private UserRepository userRepository;
      
      @Override
      public User save(User user) {
         userRepository.save(user);
      }
      
      // Getters && Setters for the repository
   
   }   

And a simple JPARepository from SpringData


   public interface UserRepository extends JPARepository<User, Long> {
   }
   
The same thing works without problems when called from our webapp (calling the service as a @ManagedProperty works ok) so the embedded project's config seems to be ok.

And here's Activiti Explorer's applicationContext 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:context="http://www.springframework.org/schema/context"
   xmlns:tx="http://www.springframework.org/schema/tx"
        xmlns:jpa="http://www.springframework.org/schema/data/jpa"
   xmlns:jee="http://www.springframework.org/schema/jee"

   xsi:schemaLocation="
         http://www.springframework.org/schema/beans
              http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
                  http://www.springframework.org/schema/tx
                  http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context-3.1.xsd
         http://www.springframework.org/schema/data/jpa
         http://www.springframework.org/schema/data/jpa/spring-jpa.xsd
         http://www.springframework.org/schema/jdbc
         http://www.springframework.org/schema/jdbc/spring-jdbc-3.1.xsd
         http://www.springframework.org/schema/jee
         http://www.springframework.org/schema/jee/spring-jee-3.1.xsd">

   <context:property-placeholder location="classpath*:jdbc.properties" />

   <!– Scan this classpath for annotated components that will be auto-registered
      as Spring beans –>
   <context:annotation-config />

   <!– scan the embedded project's components –>
        <context:component-scan base-package="edu.bedelias.*" />

   <jpa:repositories base-package="edu.bedelias.repositories*" />

   <bean
      class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />

   <!– Automatically translate hibernate/jpa exceptions into Spring's generic
      DataAccessException hierarchy for those classes annotated with Repository –>
   <bean
      class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />

   <!– JPA Entity Manager Factory –>
   <bean id="entityManagerFactory"
      class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
      <property name="dataSource" ref="dataSource" />
      <property name="jpaVendorAdapter" ref="hibernateJpaVendorAdapter" />
      <property name="packagesToScan">
         <list>
            <value>edu.bedelias.*</value>
         </list>
      </property>
      <property name="jpaProperties">
         <props>
            <!– set HibernateJpaVendorAdapter's behavior: 'create' = build a new
               DB on each run; 'update' = modify an existing database; 'create-drop' = 'create'
               and also drops tables when Hibernate closes; 'validate' = makes no changes
               to the database –>
            <prop key="hibernate.hbm2ddl.auto">create-drop</prop>
         </props>
      </property>
   </bean>

   <bean id="hibernateJpaVendorAdapter"
      class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
      <property name="showSql" value="true" />
      <property name="generateDdl" value="false" />
      <property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect" />
   </bean>

   <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
      destroy-method="close">
      <property name="driverClass" value="${jdbc.driverClass}" />
      <property name="jdbcUrl" value="${jdbc.jdbcUrl}" />
      <property name="user" value="${jdbc.user}" />
      <property name="password" value="${jdbc.password}" />
      <property name="maxPoolSize" value="${jdbc.maxPoolSize}" />
      <property name="maxStatements" value="${jdbc.maxStatements}" />
      <property name="minPoolSize" value="${jdbc.minPoolSize}" />
   </bean>

   <!– Transaction Manager is defined –>
   <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
      <property name="entityManagerFactory" ref="entityManagerFactory" />
      <property name="dataSource" ref="dataSource" />
   </bean>

   <!– Hijack the current @Session scope annotation on each @Service and make
      it last only for the duration of the thread –>
   <bean class="org.springframework.beans.factory.config.CustomScopeConfigurer">
      <property name="scopes">
         <map>
            <entry key="session">
               <bean class="org.springframework.context.support.SimpleThreadScope" />
            </entry>
         </map>
      </property>
   </bean>

   <!– Enable the configuration of transactional behavior based on annotations –>
   <tx:annotation-driven />

   <bean id="dbProperties"
      class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
      <property name="location" value="classpath:db.properties" />
      <!– Allow other PropertyPlaceholderConfigurer to run as well –>
      <property name="ignoreUnresolvablePlaceholders" value="true" />
   </bean>

   <bean id="demoDataGenerator" class="org.activiti.explorer.demo.DemoDataGenerator">
      <property name="processEngine" ref="processEngine" />
   </bean>

   <bean id="processEngineConfiguration" class="org.activiti.spring.SpringProcessEngineConfiguration">
      <property name="dataSource" ref="dataSource" />
      <property name="transactionManager" ref="transactionManager" />
      <property name="databaseSchemaUpdate" value="true" />
      <property name="jobExecutorActivate" value="true" />
      <property name="customFormTypes">
         <list>
            <ref bean="userFormType" />
         </list>
      </property>
   </bean>

   <bean id="processEngine" class="org.activiti.spring.ProcessEngineFactoryBean"
      destroy-method="destroy">
      <property name="processEngineConfiguration" ref="processEngineConfiguration" />
   </bean>

   <bean id="repositoryService" factory-bean="processEngine"
      factory-method="getRepositoryService" />
   <bean id="runtimeService" factory-bean="processEngine"
      factory-method="getRuntimeService" />
   <bean id="taskService" factory-bean="processEngine"
      factory-method="getTaskService" />
   <bean id="historyService" factory-bean="processEngine"
      factory-method="getHistoryService" />
   <bean id="managementService" factory-bean="processEngine"
      factory-method="getManagementService" />
   <bean id="identityService" factory-bean="processEngine"
      factory-method="getIdentityService" />

   <bean id="activitiLoginHandler" class="org.activiti.explorer.ui.login.DefaultLoginHandler">
      <property name="identityService" ref="identityService" />
   </bean>

   <!– Include the UI-related wiring. This UI context will be used in the
      alfresco activiti admin UI –>
   <import resource="activiti-ui-context.xml" />

   <!– Custom form types –>
   <bean id="userFormType" class="org.activiti.explorer.form.UserFormType" />

</beans>
 

I've tried going for an "Expression" approach, as suggested [url=http://forums.activiti.org/en/viewtopic.php?f=8&t=3276&p=13020
]here and here to no avail.

If anyone is curious, the URL of the project is here: http://code.google.com/p/tecnoinf-activiti/source/browse/

Thanks in advance,

Gaston

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