最近在配置renren项目中的多数据源，同时连接mysql和oracle ，由于项目本身是mysql的，oralce用到的不多，但是也需要用代码生成器生成oracle代码，所以先用renren-generator项目连接下oralce。
解决思路参考：https://blog.csdn.net/jiangyu1013/article/details/85778654
1.配置oracle数据库，打开application.yml文件，配置oralce信息：
2.yml中database修改为oracle，如下图所示
3.完整application.yml配置文件如下所示（单数据源）：
server:port: 8081# mysql
spring:datasource:type: com.alibaba.druid.pool.DruidDataSource#url: jdbc:mysql://localhost:3306/bossdb?allowMultiQueries=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false#username: root#password: *****#oracle配置-本地driverClassName: oracle.jdbc.OracleDriverurl: jdbc:oracle:thin:@127.0.0.1:1521:testusername: ****password: *****#oracle配置# driverClassName: oracle.jdbc.OracleDriver# url: jdbc:oracle:thin:@47.100.206.162:1521:xe# username: renren# password: 123456#SQLServer配置# driverClassName: com.microsoft.sqlserver.jdbc.SQLServerDriver# url: jdbc:sqlserver://192.168.10.10:1433;DatabaseName=renren_fast# username: sa# password: 123456#PostgreSQL配置# driverClassName: org.postgresql.Driver# url: jdbc:postgresql://192.168.10.10:5432/renren_fast# username: postgres# password: 123456jackson:time-zone: GMT+8date-format: yyyy-MM-dd HH:mm:ssresources:static-locations: classpath:/static/,classpath:/views/mybatis:mapperLocations: classpath:mapper/**/*.xmlpagehelper:reasonable: truesupportMethodsArguments: trueparams: count=countSql#指定数据库，可选值有【mysql、oracle、sqlserver、postgresql】
renren:database: oracle
4.运行项目，主要报错：Cannot load driver class: oracle.jdbc.OracleDriver
只配置了yml，没有配置依赖和驱动，所以运行报错
java.lang.Object.wait(Native Method)java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:43)
2020-08-11 09:51:22.610 INFO 4076 --- [ main] ConditionEvaluationReportLoggingListener : Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2020-08-11 09:51:22.618 ERROR 4076 --- [ main] o.s.boot.SpringApplication : Application run failedorg.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'dbConfig': Unsatisfied dependency expressed through field 'mySQLGeneratorDao'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mySQLGeneratorDao' defined in file [E:\MyEclipse2019\workspace\renren-generator\target\classes\io\renren\dao\MySQLGeneratorDao.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]: Unsatisfied dependency expressed through method 'sqlSessionFactory' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Generic.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Cannot load driver class: oracle.jdbc.OracleDriverat org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:584) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:370) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1336) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:572) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:495) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:759) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) ~[spring-context-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:548) ~[spring-context-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:386) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]at org.springframework.boot.SpringApplication.run(SpringApplication.java:1242) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]at org.springframework.boot.SpringApplication.run(SpringApplication.java:1230) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]at io.renren.RenrenApplication.main(RenrenApplication.java:12) [classes/:na]
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mySQLGeneratorDao' defined in file [E:\MyEclipse2019\workspace\renren-generator\target\classes\io\renren\dao\MySQLGeneratorDao.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]: Unsatisfied dependency expressed through method 'sqlSessionFactory' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Generic.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Cannot load driver class: oracle.jdbc.OracleDriverat org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1431) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1319) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:572) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:495) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:251) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1135) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1062) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:581) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]... 19 common frames omitted
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]: Unsatisfied dependency expressed through method 'sqlSessionFactory' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Generic.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Cannot load driver class: oracle.jdbc.OracleDriverat org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:733) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:475) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1246) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1096) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:535) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:495) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:251) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1135) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1062) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1416) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]... 30 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Generic.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Cannot load driver class: oracle.jdbc.OracleDriverat org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:591) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1246) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1096) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:535) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:495) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:251) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1135) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1062) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:819) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:725) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]... 43 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Cannot load driver class: oracle.jdbc.OracleDriverat org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:583) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]... 56 common frames omitted
Caused by: java.lang.IllegalStateException: Cannot load driver class: oracle.jdbc.OracleDriverat org.springframework.util.Assert.state(Assert.java:94) ~[spring-core-5.0.10.RELEASE.jar:5.0.10.RELEASE]at org.springframework.boot.autoconfigure.jdbc.DataSourceProperties.determineDriverClassName(DataSourceProperties.java:224) ~[spring-boot-autoconfigure-2.0.6.RELEASE.jar:2.0.6.RELEASE]at org.springframework.boot.autoconfigure.jdbc.DataSourceProperties.initializeDataSourceBuilder(DataSourceProperties.java:176) ~[spring-boot-autoconfigure-2.0.6.RELEASE.jar:2.0.6.RELEASE]at org.springframework.boot.autoconfigure.jdbc.DataSourceConfiguration$Generic.dataSource(DataSourceConfiguration.java:120) ~[spring-boot-autoconfigure-2.0.6.RELEASE.jar:2.0.6.RELEASE]at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_131]at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_131]at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_131]at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_131]at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]... 57 common frames omittedPicked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF-8
5.找到pom.xml，打开发现驱动是注释状态，取消注释
6.运行正常，正常连接到了oracle数据库，可以生成代码了