java - 使用@Transactional注释方法会导致 "No unique bean of type is defined: expected single bean but found 0"

Question

使用@Transactional注释实现类中的方法会引发此异常。

// Interface
public interface JobManager {

    public void process(CommandLine parameters);
}

// Implementing class
public class UserJobManager implements JobManager{

    @Transactional
    @Override
    public void process(CommandLine line) {
        // Stuff here
    }
}

Spring 配置:

<?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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
    http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context.xsd">

    <bean id="benchmarkManager" class="com.test.userjobmanager.UserJobManager"/>

    <tx:annotation-driven transaction-manager="transactionManager" order="10"/>

    <bean id="transactionManager" 
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager">

         <property name="dataSource" ref="readDataSource"/>
    </bean>

    <!-- other beans here -->
</beans>

当我访问 bean 时:

JobManager jobManager = ac.getBean(UserJobManager.class);

我有以下堆栈跟踪:

Exception in thread "main" org.springframework.beans.factory.NoSuchBeanDefinitionException: No unique bean of type [com.test.userjobmanager.UserJobManager] is defined: expected single bean but found 0: at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:269) at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1083)

如果我删除@Transactional，它就可以正常工作。 我不确定这里出了什么问题。

Answer 1

也许您正在使用创建合成类的代理技术。也就是说，您的事务bean 的真正类可能不再是UserJobManager。我建议改为按名称访问 bean:

JobManager jobManager = ac.getBean("benchmarkManager", JobManager.class)