基于注释的Spring

Question

我对春天和动感很陌生。我正在用嵌入式Activiti引擎开发基于注释的Spring应用程序。我已经实现了一些服务，SubscriptionService就是其中之一。在一个过程中，我将该服务称为bean，并使用：

activiti:expression="${subscriptionService.getContacts(publisherCode, contactType)}"

服务：

@Service
@Transactional
public class DBSubscriptionService implements SubscriptionService {
...
}

我已经分离了测试模块和web模块。测试模块从activiti.cfg.xml加载上下文

@ContextConfiguration("classpath:activiti.cfg.xml")

它是：

<bean id="processEngineConfiguration"
    class="org.activiti.engine.impl.cfg.StandaloneInMemProcessEngineConfiguration">
    <property name="databaseType" value="h2" />
    <property name="databaseSchemaUpdate" value="true" />
    <property name="jobExecutorActivate" value="false" />
    <property name="history" value="full" />
    <property name="mailServerPort" value="2025" />
</bean>

<bean id="processEngine" class="org.activiti.spring.ProcessEngineFactoryBean">
    <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="formService" factory-bean="processEngine"
    factory-method="getFormService" />

<context:component-scan base-package="cz.muni.fi.cep" />
<context:annotation-config />

在测试模块中，一切正常。但是在web模块中，当它应该调用subscriptionService Bean时，它会抛出：

    Unknown property used in expression: ${subscriptionService.getContacts(publisherCode, contactType)}
Caused by: org.activiti.engine.impl.javax.el.PropertyNotFoundException: Cannot resolve identifier 'subscriptionService'
    at org.activiti.engine.impl.juel.AstIdentifier.eval(AstIdentifier.java:83)
    at org.activiti.engine.impl.juel.AstMethod.invoke(AstMethod.java:79)
    at org.activiti.engine.impl.juel.AstMethod.eval(AstMethod.java:75)
    at org.activiti.engine.impl.juel.AstEval.eval(AstEval.java:50)
    at org.activiti.engine.impl.juel.AstNode.getValue(AstNode.java:26)
    at org.activiti.engine.impl.juel.TreeValueExpression.getValue(TreeValueExpression.java:114)
    at org.activiti.engine.impl.delegate.ExpressionGetInvocation.invoke(ExpressionGetInvocation.java:33)
    at org.activiti.engine.impl.delegate.DelegateInvocation.proceed(DelegateInvocation.java:37)
    at org.activiti.engine.impl.delegate.DefaultDelegateInterceptor.handleInvocation(DefaultDelegateInterceptor.java:25)
    at org.activiti.engine.impl.el.JuelExpression.getValue(JuelExpression.java:48)
    ... 363 more

因此，我理解的问题是，流程引擎没有使用正确的应用程序上下文，因为订阅服务被自动分配到其他类中。但我不知道怎么解决。

Web模块纯粹是基于注释的：

@EnableAutoConfiguration
@Configuration
@EntityScan(basePackages = "cz.muni.fi.cep")
@ComponentScan(basePackages = "cz.muni.fi.cep")
public class App extends WebMvcConfigurerAdapter {

    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }

    ...
} 

和Activiti配置：

@Configuration
public class ActivitiConfig {

    @Bean
    public ProcessEngine processEngine(ProcessEngineConfigurationImpl pec, ApplicationContext applicationContext) throws Exception {
        ProcessEngineFactoryBean pe = new ProcessEngineFactoryBean();
        pe.setProcessEngineConfiguration(pec);
        pe.setApplicationContext(applicationContext);

        return pe.getObject();
    }

    @Bean
    public ProcessEngineConfigurationImpl getProcessEngineConfiguration(
            DataSource dataSource,
            PlatformTransactionManager transactionManager,
            ApplicationContext context) {
        SpringProcessEngineConfiguration pec = new SpringProcessEngineConfiguration();

        pec.setDataSource(dataSource);
        pec.setDatabaseSchemaUpdate("true");
        pec.setJobExecutorActivate(true);
        pec.setHistory("full");
        pec.setMailServerPort(2025);
        pec.setDatabaseType("mysql");

        pec.setTransactionManager(transactionManager);
        pec.setApplicationContext(context);

        return pec;
    }

    @Bean
    public RuntimeService getRuntimeService(ProcessEngine processEngine) {
        return processEngine.getRuntimeService();
    }
...
}

此外，也许语境创造的顺序与此有关。

Answer 1

一切看起来都很好，我相信它可能很简单，比如订阅服务没有被扫描(它是否属于包cz.muni.fi.cep?)，或者Spring为订阅服务bean指定了另一个名称(即dbSubscriptionService或dBSubscriptionService，而不仅仅是subscriptionService)。

尝试用@Service替换DBSubscriptionService类中的@Service("subscriptionService")，它应该可以工作。