springboot-how to solve 'Failed to bind properties under '' to com.zaxxer.hikari.HikariDataSource' in SpringBoot apps

Problem

When we develop spring boot jdbc applications , sometimes, we got this problem:

> Task :app3:bootRun FAILED

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( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
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 :: Spring Boot ::        (v2.3.2.RELEASE)

2020-11-21 16:42:47.957  INFO 63354 --- [           main] com.bswen.app3.Main                      : No active profile set, falling back to default profiles: default
2020-11-21 16:42:48.268  INFO 63354 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data JDBC repositories in DEFAULT mode.
2020-11-21 16:42:48.283  INFO 63354 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 10ms. Found 0 JDBC repository interfaces.
2020-11-21 16:42:48.459 ERROR 63354 --- [           main] com.zaxxer.hikari.HikariConfig           : Failed to load driver class com.mysql.cj.jdbc.Driver from HikariConfig class classloader sun.misc.Launcher$AppClassLoader@2a139a55
2020-11-21 16:42:48.460  WARN 63354 --- [           main] s.c.a.AnnotationConfigApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$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.context.properties.bind.BindException: Failed to bind properties under '' to com.zaxxer.hikari.HikariDataSource
2020-11-21 16:42:48.467  INFO 63354 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2020-11-21 16:42:48.471 ERROR 63354 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

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

Description:

Failed to bind properties under '' to com.zaxxer.hikari.HikariDataSource:

    Property: driver-class-name
    Value: com.mysql.cj.jdbc.Driver
    Origin: "driverClassName" from property source "source"
    Reason: Failed to load driver class com.mysql.cj.jdbc.Driver in either of HikariConfig class loader or Thread context classloader

Action:

Update your application's configuration


Execution failed for task ':app3:bootRun'.
> Process 'command '/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/bin/java'' finished with non-zero exit value 1

Environment

• mysql 5.1
• spring boot 2.3

Reason

You are using the newest spring boot version to connect an old mysql. According to this post by Andreas, the reason is:

Since Spring boot was expecting a newer mysql-java-connector, which has been renamed to com.mysql.cj.jdbc.Driver, I also had to add the spring datasource driver-class-name setting in my spring boot db config.

###

Solution

So the key point to solve this problem is to tell spring boot that we are connecting to an old mysql, which version is 5.1, so the jdbc driver should be com.mysql.jdbc.Driver, not the com.mysql.cj.jdbc.Driver.

Step 1:

Change your application.properties, specify the right driver class name of mysql:

spring.datasource.driver-class-name: com.mysql.jdbc.Driver

Step 2:

Change the runtime dependency to the right jdbc driver version:

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-data-jdbc'
    runtimeOnly 'mysql:mysql-connector-java:5.1.40'
}

All the code is upload to github, you can download the example code here.