我已将应用程序升级到Spring Boot 2.2.2，现在启动时间在30秒范围内。
:: Built with Spring Boot :: 2.2.2.RELEASE
2019-12-23 10:38:06.822 INFO 4669 --- [ restartedMain] c.d.l.i.r.IdeaSubmissionRestApplication : Starting IdeaSubmissionRestApplication on wsm-93.local with PID 4669 (/Users/mhast/Developer/sts_workspaces_4_4_1/dss/ldrd_s/IdeaSubmissionRest/target/classes started by mhast in /Users/mhast/Developer/sts_workspaces_4_4_1/dss/ldrd_s/IdeaSubmissionRest)
2019-12-23 10:38:06.826 INFO 4669 --- [ restartedMain] c.d.l.i.r.IdeaSubmissionRestApplication : The following profiles are active: dev
...
2019-12-23 10:38:08.440 INFO 4669 --- [ restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8320 (http)
2019-12-23 10:38:08.447 INFO 4669 --- [ restartedMain] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2019-12-23 10:38:08.448 INFO 4669 --- [ restartedMain] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.29]
2019-12-23 10:38:08.512 INFO 4669 --- [ restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2019-12-23 10:38:08.512 INFO 4669 --- [ restartedMain] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1530 ms
2019-12-23 10:38:08.678 INFO 4669 --- [ restartedMain] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting...
2019-12-23 10:38:09.189 INFO 4669 --- [ restartedMain] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed.
2019-12-23 10:38:09.234 INFO 4669 --- [ restartedMain] o.hibernate.jpa.internal.util.LogHelper : HHH000204: Processing PersistenceUnitInfo [name: default]
2019-12-23 10:38:09.285 INFO 4669 --- [ restartedMain] org.hibernate.Version : HHH000412: Hibernate Core {5.4.9.Final}
2019-12-23 10:38:09.370 INFO 4669 --- [ restartedMain] o.hibernate.annotations.common.Version : HCANN000001: Hibernate Commons Annotations {5.1.0.Final}
2019-12-23 10:38:09.456 INFO 4669 --- [ restartedMain] org.hibernate.dialect.Dialect : HHH000400: Using dialect: org.hibernate.dialect.Oracle10gDialect
2019-12-23 10:38:37.903 INFO 4669 --- [ restartedMain] org.hibernate.tuple.PojoInstantiator : HHH000182: No default (no-argument) constructor for class: com.desertsky.ldrd.model.entities.FrsFactTableViewId (class must be instantiated by Interceptor)
2019-12-23 10:38:39.038 INFO 4669 --- [ restartedMain] o.h.e.t.j.p.i.JtaPlatformInitiator : HHH000490: Using JtaPlatform implementation: [org.hibernate.engine.transaction.jta.platform.internal.NoJtaPlatform]
2019-12-23 10:38:39.043 INFO 4669 --- [ restartedMain] j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default'
2019-12-23 10:38:40.109 WARN 4669 --- [ restartedMain] JpaBaseConfiguration$JpaWebConfiguration : spring.jpa.open-in-view is enabled by default. Therefore, database queries may be performed during view rendering. Explicitly configure spring.jpa.open-in-view to disable this warning
Oracle10gDialect的加载从10：38：09.456开始，下一个日志是28秒后。
2019-12-23 10:38:09.456 INFO 4669 --- [ restartedMain] org.hibernate.dialect.Dialect : HHH000400: Using dialect: org.hibernate.dialect.Oracle10gDialect
2019-12-23 10:38:37.903 INFO 4669 --- [ restartedMain] org.hibernate.tuple.PojoInstantiator : HHH000182: No default (no-argument) constructor for class: com.desertsky.ldrd.model.entities.FrsFactTableViewId (class must be instantiated by Interceptor)
有人知道为什么升级到Spring Boot 2.2.2之后方言加载这么慢吗？
答案 0 :(得分：0)
我在这篇文章中找到了答案。
Very slow Spring Boot application startup
我将此属性添加到了application.properties文件中，回到了快速的应用程序启动状态。
spring.jpa.properties.hibernate.temp.use_jdbc_metadata_defaults=false
JBoss Hibernate文档说：
This setting is used to control whether we should consult the JDBC metadata to determine certain Settings default values when the database may not be available (mainly in tools usage).