如何在Apache Camel DSL中回滚事务？

Question

I wrote this code for education apache camel transaction

    from("jms:SAMPLE_1")
            .transacted()
            .log("message")
            .to("jms:SAMPLE_2")
            .to("jms:SAMPLE_3")
            .log("message")
            .process(exchange -> {
                throw new Exception();
            })
           .end();

I use transacted after an error occurs I have to trigger a transaction rollback, but for some reason the messages remain in the SAMPLE_2 and SAMPLE_3 queues. Why?
UPDATE:
I added bean

@Bean(name = "PROPAGATION_REQUIRED")
public SpringTransactionPolicy propogationRequired(PlatformTransactionManager jtaTransactionManager){
    SpringTransactionPolicy propagationRequired = new SpringTransactionPolicy();
    propagationRequired.setTransactionManager(jtaTransactionManager);
propagationRequired.setPropagationBehaviorName("PROPAGATION_REQUIRED");
    return propagationRequired;
}
@Bean
PlatformTransactionManager platformTransactionManager(ConnectionFactory cf) {
    return new JmsTransactionManager(cf);
}

and fix route but this don't help me:

from("jms:SAMPLE_1")
            .transacted("PROPAGATION_REQUIRED")
            .log("message")
            .to("jms:SAMPLE_2")
            .to("jms:SAMPLE_3")
            .log("message")
            .process(exchange -> {
                throw new Exception();
            })
           .end();

I find in documentation this configuration

<blueprint ...>
<bean id="jmstx" class="org.apache.camel.component.jms.JmsComponent">
    <property name="configuration" ref="jmsConfig" />
</bean>

<bean id="jmsConfig" class="org.apache.camel.component.jms.JmsConfiguration">
    <property name="connectionFactory" ref="jmsConnectionFactory" />
    <property name="transactionManager" ref="jmsTransactionManager" />
    <property name="transacted" value="true" />
</bean>
...

how to create bean's from this xml?

Answer 1

Yes this does not work because the Camel JMS component does not know about your transaction manager etc.

As you already found out, the component configuration is missing .

I don't use plain JMS component but the specialized version for ActiveMQ but they are very similar. So I hope you can derive the missing bean from this one.

@Bean(name = "activemq") // bean name is used in URI activemq:...
public ActiveMQComponent createComponent(ConnectionFactory factory) {
    ActiveMQComponent activeMQComponent = new ActiveMQComponent();
    activeMQComponent.setConnectionFactory(factory);
    activeMQComponent.setLazyCreateTransactionManager(false);
    activeMQComponent.setTransacted(true);
    return activeMQComponent;
}

Important

As you see I don't set the transaction manager in the component. As long as you just talk to 1 broker, you don't need the tx manager stuff (you profit then from cache settings). To use transactions with your single broker

• Remove Spring transaction manager
• Remove Spring transaction policy
• Remove transacted() from Camel route

You just need to set setTransacted(true) and setLazyCreateTransactionManager(false) on the Camel JMS component and then all JMS consumers are transacted.

You can also find both setups in the Camel docs .