SpringBoot没有用到数据源启动报错

2021-10-29 12:15:46.375  WARN 10596 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'dataSourcescriptDatabaseInitializer' defined in class path resource [org/springframework/boot/autoconfigure/sql/init/DataSourceInitializationConfiguration.class]: Unsatisfied dependency expressed through method 'dataSourcescriptDatabaseInitializer' 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$Hikari.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.zaxxer.hikari.HikariDataSource]: Factory method 'dataSource' threw exception; nested exception is org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException: Failed to determine a suitable driver class
2021-10-29 12:15:46.377  INFO 10596 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2021-10-29 12:15:46.396 ERROR 10596 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.

Reason: Failed to determine a suitable driver class


Action:

Consider the following:
	If you want an embedded database (H2, HSQL or Derby), please put it on the classpath.
	If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active).


Process finished with exit code 1

SpringBoot默认会加载关于数据源的自动配置类，从而向Spring容器中注入了DataSource相关的Bean。而工程中并没有关于DataSource的相关配置，所以会报错。
org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration

@Configuration(
    proxyBeanMethods = false
)
@ConditionalOnClass({DataSource.class, EmbeddedDatabaseType.class})
@ConditionalOnMissingBean(
    type = {"io.r2dbc.spi.ConnectionFactory"}
)
@EnableConfigurationProperties({DataSourceProperties.class})
@import({DataSourcePoolmetadataProvidersConfiguration.class, InitializationSpecificCredentialsDataSourceInitializationConfiguration.class, SharedCredentialsDataSourceInitializationConfiguration.class})
public class DataSourceAutoConfiguration {
    public DataSourceAutoConfiguration() {
    }
    ...
}

通过上面的分析，只需要禁止加载DataSourceAutoConfiguration即可，而实现方式也有2种：

在启动类上加上exclude属性exclude={DataSourceAutoConfiguration.class}

@SpringBootApplication(exclude={DataSourceAutoConfiguration.class})

在application配置文件中禁止，以application.properties为例

spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration

当需要屏蔽多个自动配置类时，也可以这样

spring.autoconfigure.exclude[0]=org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration