ProcessEngine不是creationg

Question

每当我使用Spring集成运行activiti应用程序时，我都会收到以下错误：

  

org.springframework.beans.factory.BeanCreationException：创建ServletContext中定义名为'processEngine'的bean时出错   resource [/WEB-INF/config/bean-daos.xml]：bean的实例化   失败;
  嵌套异常是   org.springframework.beans.factory.BeanDefinitionStoreException：   工厂方法[public org.activiti.engine.ProcessEngine   org.activiti.engine.impl.cfg.ProcessEngineConfigurationImpl.buildProcessEngine（）]   抛出异常;
  嵌套异常是   org.activiti.engine.ActivitiException：构建ibatis时出错   SqlSessionFactory：创建文档实例时出错   原因：   java.net.UnknownHostException：mybatis.org

我的流程引擎配置文件是：

    <bean id="dataSource"           class="org.springframework.jdbc.datasource.SimpleDriverDataSource">
                    <property name="driverClass" value="org.postgresql.Driver" />
                    <property name="url" value="jdbc:postgresql://localhost:5432/activiti" />
                    <property name="username" value="postgres" />
                    <property name="password" value="*******" />
        </bean>
        <bean id="processEngineConfiguration"
            class="org.activiti.engine.impl.cfg.StandaloneProcessEngineConfiguration">
                    <property name="dataSource" ref="apacheDatasourceref" />
                    <property name="databaseSchemaUpdate" value="true" />
                    <property name="jobExecutorActivate" value="false" />
        </bean> 
        <tx:annotation-driven transaction-manager="transactionManager" /> 
        <bean id="processEngine" factory-bean="processEngineConfiguration"
                    factory-method="buildProcessEngine" />  
        <bean id="repositoryService" factory-bean="processEngineConfiguration"
                    factory-method="getRepositoryService" />
        <bean id="runtimeService" factory-bean="processEngineConfiguration"
                    factory-method="getRuntimeService" />
        <bean id="taskService" factory-bean="processEngineConfiguration"
                    factory-method="getTaskService" />
        <bean id="historyService" factory-bean="processEngineConfiguration"
                    factory-method="getHistoryService" />
        <bean id="managementService" factory-bean="processEngineConfiguration"
                    factory-method="getManagementService" />