错误详情

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean]: Factory method 'entityManagerFactory' threw exception; nested exception is java.lang.RuntimeException: Driver com.mysql.jdbc.Driver claims to not accept jdbcUrl, jdbc:mysql//127.0.0.1:3306/crawler
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:658) ~[spring-beans-5.3.8.jar:5.3.8]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:638) ~[spring-beans-5.3.8.jar:5.3.8]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1334) ~[spring-beans-5.3.8.jar:5.3.8]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177) ~[spring-beans-5.3.8.jar:5.3.8]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:564) ~[spring-beans-5.3.8.jar:5.3.8]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524) ~[spring-beans-5.3.8.jar:5.3.8]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.8.jar:5.3.8]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.8.jar:5.3.8]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.8.jar:5.3.8]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.8.jar:5.3.8]
	at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1154) ~[spring-context-5.3.8.jar:5.3.8]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:908) ~[spring-context-5.3.8.jar:5.3.8]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.8.jar:5.3.8]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.5.2.jar:2.5.2]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[spring-boot-2.5.2.jar:2.5.2]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) ~[spring-boot-2.5.2.jar:2.5.2]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:338) ~[spring-boot-2.5.2.jar:2.5.2]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) ~[spring-boot-2.5.2.jar:2.5.2]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332) ~[spring-boot-2.5.2.jar:2.5.2]
	at domain.MainApplication.main(MainApplication.java:11) ~[classes/:na]
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean]: Factory method 'entityManagerFactory' threw exception; nested exception is java.lang.RuntimeException: Driver com.mysql.jdbc.Driver claims to not accept jdbcUrl, jdbc:mysql//127.0.0.1:3306/crawler
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.3.8.jar:5.3.8]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653) ~[spring-beans-5.3.8.jar:5.3.8]
	... 19 common frames omitted
Caused by: java.lang.RuntimeException: Driver com.mysql.jdbc.Driver claims to not accept jdbcUrl, jdbc:mysql//127.0.0.1:3306/crawler
	at com.zaxxer.hikari.util.DriverDataSource.<init>(DriverDataSource.java:110) ~[HikariCP-4.0.3.jar:na]
	at com.zaxxer.hikari.pool.PoolBase.initializeDataSource(PoolBase.java:331) ~[HikariCP-4.0.3.jar:na]
	at com.zaxxer.hikari.pool.PoolBase.<init>(PoolBase.java:114) ~[HikariCP-4.0.3.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:108) ~[HikariCP-4.0.3.jar:na]
	at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) ~[HikariCP-4.0.3.jar:na]
	at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:158) ~[spring-jdbc-5.3.8.jar:5.3.8]
	at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:116) ~[spring-jdbc-5.3.8.jar:5.3.8]
	at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:79) ~[spring-jdbc-5.3.8.jar:5.3.8]
	at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:330) ~[spring-jdbc-5.3.8.jar:5.3.8]
	at org.springframework.boot.jdbc.EmbeddedDatabaseConnection.isEmbedded(EmbeddedDatabaseConnection.java:184) ~[spring-boot-2.5.2.jar:2.5.2]
	at org.springframework.boot.autoconfigure.orm.jpa.HibernateDefaultDdlAutoProvider.getDefaultDdlAuto(HibernateDefaultDdlAutoProvider.java:42) ~[spring-boot-autoconfigure-2.5.2.jar:2.5.2]
	at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration.lambda$getVendorProperties$1(HibernateJpaConfiguration.java:130) ~[spring-boot-autoconfigure-2.5.2.jar:2.5.2]
	at org.springframework.boot.autoconfigure.orm.jpa.HibernateSettings.getDdlAuto(HibernateSettings.java:41) ~[spring-boot-autoconfigure-2.5.2.jar:2.5.2]
	at org.springframework.boot.autoconfigure.orm.jpa.HibernateProperties.determineDdlAuto(HibernateProperties.java:143) ~[spring-boot-autoconfigure-2.5.2.jar:2.5.2]
	at org.springframework.boot.autoconfigure.orm.jpa.HibernateProperties.getAdditionalProperties(HibernateProperties.java:103) ~[spring-boot-autoconfigure-2.5.2.jar:2.5.2]
	at org.springframework.boot.autoconfigure.orm.jpa.HibernateProperties.determineHibernateProperties(HibernateProperties.java:95) ~[spring-boot-autoconfigure-2.5.2.jar:2.5.2]
	at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration.getVendorProperties(HibernateJpaConfiguration.java:132) ~[spring-boot-autoconfigure-2.5.2.jar:2.5.2]
	at org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.entityManagerFactory(JpaBaseConfiguration.java:132) ~[spring-boot-autoconfigure-2.5.2.jar:2.5.2]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.3.8.jar:5.3.8]
	... 20 common frames omitted


Process finished with exit code 1

第一次遇见这种错误，网友也给了很多解决方案

1. 有的说是导包错误
2. 有的说在类上加上@Proxy(lazy = false)的注解
3. 还有的说是pom中坐标依赖版本有问题
   最后我发现这些问题都不是，往往最难解决的bug都是用最朴素的解决方案最终发现问题所在，连接数据库的url中少一个分号符号“:”

错误截图

加上":"好后

问题解决

总结

1. 当有bug出现时不要慌张，往往越高级的bug修改起来越简单
2. 出现bug不能一直盯着报错的第一行，因为核心错误极有可能不在前几行，如本文中的错误前面提醒的错误是Error creating bean with name ‘entityManagerFactory’ defined in class path resource…，但是真正的错误和它并没有关系。在控制台的后面明显的打印了一行Caused by: java.lang.RuntimeException: Driver com.mysql.jdbc.Driver claims to not accept jdbcUrl, jdbc:mysql//127.0.0.1:3306/crawler，告诉我们是数据库连接有问题。