遗留代码中的Spring Boot集成

Question

我很难将spring-boot应用程序作为另一个java（非Spring）应用程序的依赖项。

我被要求用一些方法和对Oracle数据库的访问来开发一个新的REST API。为此，我使用了Spring-boot，应用程序本身或部署在服务器上都运行良好。经过几次调整，我把它分成了几个模块，如下所示：

• models:包含业务代码的模型对象
• API:包含业务代码和实际API
  • 对模型有依赖关系
  • 包含连接到数据库所需的所有属性
  null

  <?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">
  
      <context:component-scan  base-package="be.belga.mediaservice"/>
      <context:annotation-config />
  </beans>
  

  @Component
  @EnableJpaRepositories("be.belga.mediaservice.dao")
  public class SpringContext {
  
  private SpringContext() {}
  
  
  private static class ApplicationContextHolder {
      private static ApplicationContext instance = new ClassPathXmlApplicationContext("application-context.xml");
  }
  
  public static ApplicationContext getInstance() {
      return ApplicationContextHolder.instance;
  }
  }
  

  MediaServiceAPI mediaServiceAPI = (MediaServiceAPI) 
  SpringContext.getInstance().getBean("mediaServiceAPI");
  

  Exception in thread "main" java.lang.ExceptionInInitializerError
  at be.belga.mediaservice.util.SpringContext.getInstance(SpringContext.java:20)
  at Test.main(Test.java:10)
  Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mediaValueServiceImpl' defined in URL [jar:file:/home/mike/.m2/repository/be/belga/mediaservice-api/0.1.7/mediaservice-api-0.1.7.jar!/be/belga/mediaservice/service/impl/MediaValueServiceImpl.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'socialMediaServiceImpl' defined in URL [jar:file:/home/mike/.m2/repository/be/belga/mediaservice-api/0.1.7/mediaservice-api-0.1.7.jar!/be/belga/mediaservice/service/impl/SocialMediaServiceImpl.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'socialMetricsRepository': Cannot create inner bean '(inner bean)#5afa3c9' of type [org.springframework.orm.jpa.SharedEntityManagerCreator] while setting bean property 'entityManager'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#5afa3c9': Cannot resolve reference to bean 'entityManagerFactory' while setting constructor argument; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'entityManagerFactory' available
  at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749)
  at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:189)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1193)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1095)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
  at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
  13:39:04.731 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Retrieved dependent beans for bean '(inner bean)#7ef82753': [socialMetricsRepository]
  13:39:04.731 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Retrieved dependent beans for bean '(inner bean)#202b0582': [(inner bean)#7ef82753]
  13:39:04.732 [main] WARN org.springframework.context.support.ClassPathXmlApplicationContext - Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mediaValueServiceImpl' defined in URL [jar:file:/home/mike/.m2/repository/be/belga/mediaservice-api/0.1.7/mediaservice-api-0.1.7.jar!/be/belga/mediaservice/service/impl/MediaValueServiceImpl.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'socialMediaServiceImpl' defined in URL [jar:file:/home/mike/.m2/repository/be/belga/mediaservice-api/0.1.7/mediaservice-api-0.1.7.jar!/be/belga/mediaservice/service/impl/SocialMediaServiceImpl.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'socialMetricsRepository': Cannot create inner bean '(inner bean)#5afa3c9' of type [org.springframework.orm.jpa.SharedEntityManagerCreator] while setting bean property 'entityManager'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#5afa3c9': Cannot resolve reference to bean 'entityManagerFactory' while setting constructor argument; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'entityManagerFactory' available
  13:39:04.732 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@1283bb96: defining beans [mediaValueForPressCommand,mediaValueServiceImpl,socialMediaServiceImpl,mediaReachScoreServiceImpl,XMLUtil,springContext,mediaServiceAPI,twitterSocialMediaServiceFacadeImpl,youtubeRestSocialMediaServiceFacadeImpl,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.internalPersistenceAnnotationProcessor,org.springframework.context.event.internalEventListenerProcessor,org.springframework.context.event.internalEventListenerFactory,org.springframework.data.jpa.repository.config.JpaRepositoryConfigExtension#0,emBeanDefinitionRegistrarPostProcessor,jpaMappingContext,jpaContext,agenciesMetricsRepository,CIMMetricsRepository,systemMetricsRepository,socialMetricsRepository,serviceTypeValueRepository,keywordsRepository]; root of factory hierarchy
  at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
  at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
  at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
  at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761)
  at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)
  at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)
  at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
  at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
  at be.belga.mediaservice.util.SpringContext$ApplicationContextHolder.<clinit>(SpringContext.java:16)
  ... 2 more
  Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'socialMediaServiceImpl' defined in URL [jar:file:/home/mike/.m2/repository/be/belga/mediaservice-api/0.1.7/mediaservice-api-0.1.7.jar!/be/belga/mediaservice/service/impl/SocialMediaServiceImpl.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'socialMetricsRepository': Cannot create inner bean '(inner bean)#5afa3c9' of type [org.springframework.orm.jpa.SharedEntityManagerCreator] while setting bean property 'entityManager'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#5afa3c9': Cannot resolve reference to bean 'entityManagerFactory' while setting constructor argument; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'entityManagerFactory' available
  at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749)
  at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:189)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1193)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1095)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
  at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
  at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
  at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
  at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
  at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208)
  at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138)
  at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
  at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:835)
  at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741)
  ... 17 more
  Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'socialMetricsRepository': Cannot create inner bean '(inner bean)#5afa3c9' of type [org.springframework.orm.jpa.SharedEntityManagerCreator] while setting bean property 'entityManager'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#5afa3c9': Cannot resolve reference to bean 'entityManagerFactory' while setting constructor argument; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'entityManagerFactory' available
  at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:313)
  at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:129)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1531)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1276)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
  at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
  at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
  at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
  at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
  at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208)
  at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138)
  at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
  at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:835)
  at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741)
  ... 31 more
  Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#5afa3c9': Cannot resolve reference to bean 'entityManagerFactory' while setting constructor argument; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'entityManagerFactory' available
  at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:359)
  at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:108)
  at org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:634)
  at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:448)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513)
  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
  at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:299)
  ... 45 more
  Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'entityManagerFactory' available
  at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:687)
  at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1207)
  at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:284)
  at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
  at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:351)
  ... 53 more
  

  是否有一种方法可以实际使用我的应用程序的API部分作为其他java应用程序的依赖项？

Answer 1

您的核心API、模型和实现不应该依赖于Spring容器，在这种情况下，任何其他Java应用程序都可以自由地使用它们，只要它能够提供所有所需的依赖关系。

你可能会想，“好吧，但这对我有什么帮助？”。在想出一个有效的解决方案之前，我们需要了解更多。

当你说你已经把事情分成模块时，你是说一个单独的罐子来存放模型、API和REST的东西？

这些JAR应该可以作为其他应用程序的依赖项直接使用。其他应用程序应该不需要使用Spring（除非它们已经在使用Spring）。