Failed to bind properties under 'spring.datasource

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 :: Spring Boot ::        (v2.1.1.RELEASE)

2018-12-21 23:22:43.553  INFO 8948 --- [           main] com.example.jdbc.DemoApplicationTests    : Starting DemoApplicationTests on ZB-PF11HMGK with PID 8948 (started by liwen406 in D:\javaspaces\githup\mysqldome)
2018-12-21 23:22:43.554  INFO 8948 --- [           main] com.example.jdbc.DemoApplicationTests    : No active profile set, falling back to default profiles: default
2018-12-21 23:22:45.531  WARN 8948 --- [           main] o.s.w.c.s.GenericWebApplicationContext   : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'helloControler': Unsatisfied dependency expressed through field 'jdbcTemplate'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration$JdbcTemplateConfiguration': Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.boot.context.properties.ConfigurationPropertiesBindException: Error creating bean with name 'druid': Could not bind properties to 'DruidDataSource' : prefix=spring.datasource, ignoreInvalidFields=false, ignoreUnknownFields=true; nested exception is org.springframework.boot.context.properties.bind.BindException: Failed to bind properties under 'spring.datasource' to javax.sql.DataSource
2018-12-21 23:22:45.539  INFO 8948 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2018-12-21 23:22:45.542 ERROR 8948 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

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

Description:

Failed to bind properties under 'spring.datasource' to javax.sql.DataSource:

    Property: spring.datasource.filters
    Value: stat,wall,log4j
    Origin: class path resource [application.yml]:21:14
    Reason: org.apache.log4j.Priority

Action:

Update your application's configuration

2018-12-21 23:22:45.551 ERROR 8948 --- [           main] o.s.test.context.TestContextManager      : Caught exception while allowing TestExecutionListener [org.springframework.test.context.web.ServletTestExecutionListener@1a4b042] to prepare test instance [com.example.jdbc.DemoApplicationTests@1d44a19]

讲解方法：

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>