遵循"十二因子应用"建议，我的所有春季启动应用程序都能在没有数据库的情况下启动，只有在数据库可用时，健康终点状态才能变得健康。那挺好的。但是我的新弹簧启动应用程序包括弹簧批量，它打破了此功能。
问题很容易复制，重复使用此项目
使用PostgreSQL驱动程序将其转换为Web应用程序，添加：
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>42.2.5</version>
</dependency>
添加一个应用程序。
spring.datasource.url=jdbc:postgresql://localhost:5432/exp_sesame
spring.datasource.driver-class-name=org.postgresql.Driver
spring.datasource.username=ADMIN
spring.datasource.password=ADMIN
spring.batch.initialize-schema=always
然后，如果启动此应用程序，它将失败。
org.postgresql.util.PSQLException: Connection to localhost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.
at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:280) ~[postgresql-42.2.5.jar:42.2.5]
at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49) ~[postgresql-42.2.5.jar:42.2.5]
at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:195) ~[postgresql-42.2.5.jar:42.2.5]
at org.postgresql.Driver.makeConnection(Driver.java:454) ~[postgresql-42.2.5.jar:42.2.5]
at org.postgresql.Driver.connect(Driver.java:256) ~[postgresql-42.2.5.jar:42.2.5]
at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:136) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:369) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:198) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:467) [HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:541) [HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115) [HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) [HikariCP-3.2.0.jar:na]
at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:157) [spring-jdbc-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115) [spring-jdbc-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78) [spring-jdbc-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:323) [spring-jdbc-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.boot.jdbc.EmbeddedDatabaseConnection.isEmbedded(EmbeddedDatabaseConnection.java:123) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.boot.autoconfigure.jdbc.DataSourceInitializer.isEmbedded(DataSourceInitializer.java:140) [spring-boot-autoconfigure-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.boot.autoconfigure.jdbc.DataSourceInitializer.isEnabled(DataSourceInitializer.java:132) [spring-boot-autoconfigure-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.boot.autoconfigure.jdbc.DataSourceInitializer.createSchema(DataSourceInitializer.java:98) [spring-boot-autoconfigure-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.boot.autoconfigure.jdbc.DataSourceInitializerInvoker.afterPropertiesSet(DataSourceInitializerInvoker.java:64) [spring-boot-autoconfigure-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1837) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1774) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:224) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveNamedBean(DefaultListableBeanFactory.java:1115) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveBean(DefaultListableBeanFactory.java:407) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:341) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:335) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.boot.autoconfigure.jdbc.DataSourceInitializerPostProcessor.postProcessAfterInitialization(DataSourceInitializerPostProcessor.java:55) ~[spring-boot-autoconfigure-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:429) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1782) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1247) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1167) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:593) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:374) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1411) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:392) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1321) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1160) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1247) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1167) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:593) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:374) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1411) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) [spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:849) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877) ~[spring-context-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.6.RELEASE.jar:5.1.6.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
at hello.Application.main(Application.java:10) ~[classes/:na]
弹簧批量和数据库具有很强的耦合，我明白它应该没有它(懒惰的init(。
当前的解决方法
我在不会自动启动的儿童上下文中移动弹簧豆豆。在主要的春季上下文中，我有一个调度程序，该调度程序会以编程方式检查数据库健康执行器，并在数据库启动时创建子上下文。
有人对此有回馈吗？
thx folks
出色的点！实际上，这不是春季批次本身特定的，因为春季批次需要DataSource bean，就像任何其他应用程序一样。
关键是DataSource应为"十二个因子"准备(如果这很有意义(，如果数据库降低或尚未启动，则重试获得连接。
Spring Boot中有一个关于此功能的开放问题：请参阅第4779期。可以在此处找到使用spring-retry的示例，以使用此重试功能来装饰数据源。
ftr，我建议Kelsey Hightower的12个破裂应用程序文章，他在其中解决了相同的问题(请参阅Eliminate the need to deploy services in a specific order部分(。代码示例写在Golang中，但这个想法是相同的。
希望这会有所帮助。