2
我有一個使用Spring Data和Hibernate進行數據訪問的Spring Boot應用程序。我最初遇到了很長的應用程序啓動時間。因此，基於這個answer，我將'hibernate.temp.use_jdbc_metadata_defaults'設置爲'false'作爲系統屬性（-D）。應用程序啓動時間問題已解決。當移動到application.properties時系統屬性停止生效
現在，我將該配置從系統屬性移至application.properties。延遲的應用程序啓動問題已返回。
我application.properties：
hibernate.temp.use_jdbc_metadata_defaults=false
spring.jpa.database-platform=org.hibernate.dialect.PostgreSQLDialect
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=none
spring.datasource.validation-query=SELECT 1
spring.datasource.testOnBorrow=true
spring.datasource.testWhileIdle=true
設置 「org.springframework.core.env」，以 「調試」 記錄後，我看到屬性從application.properties解決（如預期）。
INFO | jvm 1 | 2015/07/20 19:47:15 | 19:47:15.211 [WrapperJarAppMain] DEBUG o.s.c.e.PropertySourcesPropertyResolver - Found key 'spring.jpa.database-platform' in [applicationConfig: [classpath:/application.properties]] with type [String] and value 'org.hibernate.dialect.PostgreSQLDialect'
...
INFO | jvm 1 | 2015/07/20 19:47:15 | 19:47:15.226 [WrapperJarAppMain] DEBUG o.s.c.e.PropertySourcesPropertyResolver - Found key 'hibernate.temp.use_jdbc_metadata_defaults' in [applicationConfig: [classpath:/application.properties]] with type [String] and value 'false'
...
INFO | jvm 1 | 2015/07/20 19:47:15 | 19:47:15.229 [WrapperJarAppMain] DEBUG o.s.c.e.PropertySourcesPropertyResolver - Found key 'spring.jpa.hibernate.ddl-auto' in [applicationConfig: [classpath:/application.properties]] with type [String] and value 'none'
在延遲啓動期間，應用程序在特定點停頓，然後恢復。當止步不前，「jstack」荷蘭國際集團的JVM提供了以下結果：
INFO | jvm 1 | 2015/07/20 19:47:58 | "WrapperJarAppMain" #20 prio=5 os_prio=0 tid=0x00007fb1ec02b800 nid=0x1d39 runnable [0x00007fb248257000]
INFO | jvm 1 | 2015/07/20 19:47:58 | java.lang.Thread.State: RUNNABLE
INFO | jvm 1 | 2015/07/20 19:47:58 | at java.net.SocketInputStream.socketRead0(Native Method)
INFO | jvm 1 | 2015/07/20 19:47:58 | at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
INFO | jvm 1 | 2015/07/20 19:47:58 | at java.net.SocketInputStream.read(SocketInputStream.java:170)
INFO | jvm 1 | 2015/07/20 19:47:58 | at java.net.SocketInputStream.read(SocketInputStream.java:141)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.postgresql.core.VisibleBufferedInputStream.readMore(VisibleBufferedInputStream.java:143)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.postgresql.core.VisibleBufferedInputStream.ensureBytes(VisibleBufferedInputStream.java:112)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.postgresql.core.VisibleBufferedInputStream.read(VisibleBufferedInputStream.java:71)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.postgresql.core.PGStream.ReceiveChar(PGStream.java:282)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1803)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
INFO | jvm 1 | 2015/07/20 19:47:58 | - locked <0x000000077a9f8ca0> (a org.postgresql.core.v3.QueryExecutorImpl)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:570)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:420)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.postgresql.jdbc2.TypeInfoCache.getPGType(TypeInfoCache.java:323)
INFO | jvm 1 | 2015/07/20 19:47:58 | - locked <0x000000077aa00ce0> (a org.postgresql.jdbc2.TypeInfoCache)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.postgresql.jdbc2.TypeInfoCache.getSQLType(TypeInfoCache.java:175)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.postgresql.jdbc2.TypeInfoCache.requiresQuoting(TypeInfoCache.java:711)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.postgresql.jdbc2.AbstractJdbc2DatabaseMetaData.getTypeInfo(AbstractJdbc2DatabaseMetaData.java:4002)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.hibernate.engine.jdbc.spi.TypeInfo.extractTypeInfo(TypeInfo.java:101)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:163)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.hibernate.cfg.Configuration.buildTypeRegistrations(Configuration.java:1887)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1845)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:852)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:845)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:398)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:844)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:343)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:318)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1633)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1570)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
INFO | jvm 1 | 2015/07/20 19:47:58 | - locked <0x00000006dc2676d0> (a java.util.concurrent.ConcurrentHashMap)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:956)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:747)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
INFO | jvm 1 | 2015/07/20 19:47:58 | - locked <0x00000006dbd48650> (a java.lang.Object)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:686)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.boot.SpringApplication.run(SpringApplication.java:957)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.boot.SpringApplication.run(SpringApplication.java:946)
INFO | jvm 1 | 2015/07/20 19:47:58 | at xyz.abc.AppApplication.main(AppApplication.java:10)
INFO | jvm 1 | 2015/07/20 19:47:58 | at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
INFO | jvm 1 | 2015/07/20 19:47:58 | at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
INFO | jvm 1 | 2015/07/20 19:47:58 | at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
INFO | jvm 1 | 2015/07/20 19:47:58 | at java.lang.reflect.Method.invoke(Method.java:497)
INFO | jvm 1 | 2015/07/20 19:47:58 | at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:53)
INFO | jvm 1 | 2015/07/20 19:47:58 | at java.lang.Thread.run(Thread.java:745)
INFO | jvm 1 | 2015/07/20 19:47:58 |
從「org.postgresql.jdbc2.TypeInfoCache.getSQLType」（在上面堆），我覺得休眠還是試圖加載元數據。這與我的配置相反。
我將不勝感激關於如何將配置從系統屬性移動到application.properties的任何指針可能導致它無法生效？
[spring.jpa.properties']的前綴，[解釋] [http://docs.spring.io/spring-boot/docs/current/reference/html/howto-data-access.html#howto-配置-JPA特性）。 –