SpringBoot集成Camunda 启动失败

ERROR

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APPLICATION FAILED TO START
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Description:

Field processEngine in org.camunda.bpm.engine.spring.SpringProcessEngineServicesConfiguration required a bean of type 'org.camunda.bpm.engine.ProcessEngine' that could not be found.


Action:

Consider defining a bean of type 'org.camunda.bpm.engine.ProcessEngine' in your configuration.

Solution

Spring Boot 2.1以上的版本不支持Camunda 需要将版本下调到 2.0.2.RELEASE.

Reason

Camunda配置类 CamundaBpmAutoConfiguration 上面有个Import 注解，注入了一个
SpringProcessEngineServicesConfiguration类，
然而SpringProcessEngineServicesConfiguration类中有个自动注入类，ProcessEngine
坑爹的就是，SpringProcessEngineServicesConfiguration中需要注入的ProcessEngine的ProcessEngineFactoryBean居然是在CamundaBpmAutoConfiguration类中通过@Bean 注解注入到容器中

猜测 （没有验证）

如果2.0.2的spring boot 是先加载CamundaBpmAutoConfiguration类中的@Bean 再加载@Import 那就没事，
2.1.0以上 是先加载@import 再加载@Bean 就大条了，SpringProcessEngineServicesConfiguration中的ProcessEngine就会在ProcessEngineFactoryBean初始化之前，被调用，于是就有上面的ERROR了；