无法从 HikariConfig 加载驱动程序 class com.mysql.cj.jdbc.Driver

Question

I'm pretty new to java/spring and trying to connect my project to a mysql database but am getting this error when I run the application:

2022-12-31T19:24:59.857+01:00 ERROR 76110 --- [           main] com.zaxxer.hikari.HikariConfig           : Failed to load driver class com.mysql.cj.jdbc.Driver from HikariConfig class classloader jdk.internal.loader.ClassLoaders$AppClassLoader@251a69d7

Error starting ApplicationContext. To display the condition evaluation report re-run your application with 'debug' enabled.
2022-12-31T19:24:59.871+01:00 ERROR 76110 --- [           main] o.s.boot.SpringApplication               : Application run failed

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: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class]: Failed to instantiate [com.zaxxer.hikari.HikariDataSource]: Factory method 'dataSource' threw exception with message: Failed to load driver class com.mysql.cj.jdbc.Driver in either of HikariConfig class loader or Thread context classloader
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:798) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:548) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1324) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1161) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:561) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:521) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:326) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:324) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:313) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1130) ~[spring-context-6.0.3.jar:6.0.3]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:905) ~[spring-context-6.0.3.jar:6.0.3]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:584) ~[spring-context-6.0.3.jar:6.0.3]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[spring-boot-3.0.1.jar:3.0.1]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:730) ~[spring-boot-3.0.1.jar:3.0.1]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:432) ~[spring-boot-3.0.1.jar:3.0.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:308) ~[spring-boot-3.0.1.jar:3.0.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1302) ~[spring-boot-3.0.1.jar:3.0.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1291) ~[spring-boot-3.0.1.jar:3.0.1]
    at com.example.java2.Java2Application.main(Java2Application.java:12) ~[classes/:na]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class]: Failed to instantiate [com.zaxxer.hikari.HikariDataSource]: Factory method 'dataSource' threw exception with message: Failed to load driver class com.mysql.cj.jdbc.Driver in either of HikariConfig class loader or Thread context classloader
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:657) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:645) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1324) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1161) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:561) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:521) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:326) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:324) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:254) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1405) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1325) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:885) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:789) ~[spring-beans-6.0.3.jar:6.0.3]
    ... 21 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.zaxxer.hikari.HikariDataSource]: Factory method 'dataSource' threw exception with message: Failed to load driver class com.mysql.cj.jdbc.Driver in either of HikariConfig class loader or Thread context classloader
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:171) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653) ~[spring-beans-6.0.3.jar:6.0.3]
    ... 35 common frames omitted
Caused by: java.lang.RuntimeException: Failed to load driver class com.mysql.cj.jdbc.Driver in either of HikariConfig class loader or Thread context classloader
    at com.zaxxer.hikari.HikariConfig.setDriverClassName(HikariConfig.java:488) ~[HikariCP-5.0.1.jar:na]
    at org.springframework.boot.jdbc.DataSourceBuilder$MappedDataSourceProperty.set(DataSourceBuilder.java:479) ~[spring-boot-3.0.1.jar:3.0.1]
    at org.springframework.boot.jdbc.DataSourceBuilder$MappedDataSourceProperties.set(DataSourceBuilder.java:373) ~[spring-boot-3.0.1.jar:3.0.1]
    at org.springframework.boot.jdbc.DataSourceBuilder.build(DataSourceBuilder.java:183) ~[spring-boot-3.0.1.jar:3.0.1]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceConfiguration.createDataSource(DataSourceConfiguration.java:48) ~[spring-boot-autoconfigure-3.0.1.jar:3.0.1]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceConfiguration$Hikari.dataSource(DataSourceConfiguration.java:90) ~[spring-boot-autoconfigure-3.0.1.jar:3.0.1]
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:578) ~[na:na]
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:139) ~[spring-beans-6.0.3.jar:6.0.3]
    ... 36 common frames omitted


Process finished with exit code 1

None of the solutions ( 1 , 2 ) seem to work. This is my applications.properties file:

spring.datasource.url=jdbc:mysql://localhost:3306/java
spring.datasource.username=root
spring.datasource.password=...
spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL8InnoDBDialect
spring.jpa.properties.hibernate.format_sql=true

and this my pom.xml file:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.0.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>java2</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>java2</name>
    <description>java2</description>
    <properties>
        <java.version>19</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

I'm using Intellij IDEA Ultimate , the jakarta plugin is installed and the database tool is already connected to the mysql database but I can't get it to work with my spring app .

Answer 1

I think your dialect is wrong. Remove that dialect configuration you have and try to use these configurations: spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver spring.jpa.database-platform=org.hibernate.dialect.MySQLDialect

Answer 2

This error message indicates that the MySQL JDBC driver was not found by the application.

To fix this error, you will need to make sure that the MySQL JDBC driver is included in your project's classpath. You can do this by adding the driver as a dependency in your project's build file (such as pom.xml if you are using Maven) and then rebuilding the project.

For example, if you are using Maven, you can add the following dependency to your pom.xml file:

<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>8.0.23</version>

Then, rebuild your project by running mvn clean install or by using your build tool's equivalent command.

After rebuilding the project, the MySQL JDBC driver should be available in the classpath, and the application should be able to load it.

If you continue to have issues, it may be helpful to double-check the configuration for your database connection, including the JDBC URL, username, and password. Make sure that these values are correct and that the database is running and accessible from the application.