引起原因：java.lang.IllegalStateException：无法加载驱动程序类：org.mariadb.jdbc.Driver-Spring Cloud Data Flow

Question

我正在使用Spring Cloud Data Flow和Spring Batch示例。在此示例中，我以per this link的身份使用以下命令启动了Spring Cloud Data Flow Server

java -jar spring-cloud-dataflow-server-local-1.7.4.RELEASE.jar-> spring.datasource.url = jdbc：mysql：// localhost：3306 / test --spring.datasource.username = root-？spring.datasource.password = root --spring.datasource.driver-class-name = org.mariadb.jdbc.Driver＆

但是我使用的Spring Batch代码仅使用MySQL，并使用它进行了全面开发。

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test?createDatabaseIfNotExist=true
spring.datasource.username=root
spring.datasource.password=root
spring.batch.initialize-schema=always

当我在SCDF UI中创建任务并执行任务时，它给我以下错误-

Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.batch.core.configuration.annotation.SimpleBatchConfiguration': Unsatisfied dependency expressed through field 'dataSource'; 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$Hikari.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.zaxxer.hikari.HikariDataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Cannot load driver class: org.mariadb.jdbc.Driver
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:643) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:116) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1422) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:409) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1287) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1207) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    ... 26 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.zaxxer.hikari.HikariDataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Cannot load driver class: org.mariadb.jdbc.Driver
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:656) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:636) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1287) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1207) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    ... 48 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.zaxxer.hikari.HikariDataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Cannot load driver class: org.mariadb.jdbc.Driver
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:651) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    ... 61 common frames omitted
Caused by: java.lang.IllegalStateException: Cannot load driver class: org.mariadb.jdbc.Driver
    at org.springframework.util.Assert.state(Assert.java:94) ~[spring-core-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceProperties.determineDriverClassName(DataSourceProperties.java:222) ~[spring-boot-autoconfigure-2.2.2.RELEASE.jar!/:2.2.2.RELEASE]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceProperties.initializeDataSourceBuilder(DataSourceProperties.java:174) ~[spring-boot-autoconfigure-2.2.2.RELEASE.jar!/:2.2.2.RELEASE]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceConfiguration.createDataSource(DataSourceConfiguration.java:43) ~[spring-boot-autoconfigure-2.2.2.RELEASE.jar!/:2.2.2.RELEASE]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceConfiguration$Hikari.dataSource(DataSourceConfiguration.java:85) ~[spring-boot-autoconfigure-2.2.2.RELEASE.jar!/:2.2.2.RELEASE]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_151]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_151]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_151]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_151]
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    ... 62 common frames omitted

JobConfiguration.java

@Configuration
public class JobConfiguration {
    @Autowired
    private JobBuilderFactory jobBuilderFactory;

    @Autowired
    private StepBuilderFactory stepBuilderFactory;

    @Autowired
    private DataSource dataSource;

    @Bean
    public JdbcPagingItemReader<Customer> customerPagingItemReader(){
        // reading database records using JDBC in a paging fashion
        JdbcPagingItemReader<Customer> reader = new JdbcPagingItemReader<>();
        reader.setDataSource(this.dataSource);
        reader.setFetchSize(1000);
        reader.setRowMapper(new CustomerRowMapper());

        // Sort Keys
        Map<String, Order> sortKeys = new HashMap<>();
        sortKeys.put("id", Order.ASCENDING);

        // MySQL implementation of a PagingQueryProvider using database specific features.
        MySqlPagingQueryProvider queryProvider = new MySqlPagingQueryProvider();
        queryProvider.setSelectClause("id, firstName, lastName, birthdate");
        queryProvider.setFromClause("from customer");
        queryProvider.setSortKeys(sortKeys);

        reader.setQueryProvider(queryProvider);

        return reader;
    }


    @Bean
    public FlatFileItemWriter<Customer> jsonItemWriter() throws Exception{
        String customerOutputPath = File.createTempFile("customerOutput", ".out").getAbsolutePath();
        System.out.println(">> Output Path = "+customerOutputPath);

        FlatFileItemWriter<Customer> writer = new FlatFileItemWriter<>();
        writer.setLineAggregator(new CustomLineAggregator());
        writer.setResource(new FileSystemResource(customerOutputPath));
        writer.afterPropertiesSet();

        return writer;
    }

    @Bean
    public StaxEventItemWriter<Customer> xmlItemWriter() throws Exception{
        String customerOutputPath = File.createTempFile("customerOutput", ".out").getAbsolutePath();
        System.out.println(">> Output Path = "+customerOutputPath);

        Map<String, Class> aliases = new HashMap<>();
        aliases.put("customer", Customer.class);

        XStreamMarshaller marshaller = new XStreamMarshaller();
        marshaller.setAliases(aliases);

        // StAX and Marshaller for serializing object to XML. 
        StaxEventItemWriter<Customer> writer = new StaxEventItemWriter<>();
        writer.setRootTagName("customers");
        writer.setMarshaller(marshaller);
        writer.setResource(new FileSystemResource(customerOutputPath));
        writer.afterPropertiesSet();

        return writer;
    }


    @Bean
    public ClassifierCompositeItemWriter<Customer> classifierCustomerCompositeItemWriter() throws Exception{
        ClassifierCompositeItemWriter<Customer> compositeItemWriter = new ClassifierCompositeItemWriter<>();
        compositeItemWriter.setClassifier(new CustomerClassifier(xmlItemWriter(), jsonItemWriter()));

        return compositeItemWriter;
    }


    @Bean
    public Step step1() throws Exception {
        return stepBuilderFactory.get("step1")
                .<Customer, Customer> chunk(10)
                .reader(customerPagingItemReader())
                .writer(classifierCustomerCompositeItemWriter())
                .stream(xmlItemWriter())
                .stream(jsonItemWriter())
                .build();
    }

    @Bean
    public Job job() throws Exception {
        return jobBuilderFactory.get("job")
                .start(step1())
                .build();
    }
}

pom.xml

<?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 http://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>2.2.2.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>classifierWrittingMultipleDestinations</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>classifierWrittingMultipleDestinations</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-batch</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <!-- Spring OXM -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-oxm</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.mariadb.jdbc</groupId>
            <artifactId>mariadb-java-client</artifactId>
            <version>2.6.0</version>
        </dependency>

        <dependency>
            <groupId>com.thoughtworks.xstream</groupId>
            <artifactId>xstream</artifactId>
            <version>1.4.7</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.2</version>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.batch</groupId>
            <artifactId>spring-batch-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

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

注意- MySQL版本是8.0.18

Answer 1

由于您在批处理应用程序中使用MySQL JDBC驱动程序，因此我假设您也为SCDF服务器使用了相同的MySQL数据库。在这种情况下，您需要在启动SCDF服务器时为spring数据源驱动程序类名称属性设置MySQL驱动程序类。

PS：我看到您创建了多个SO问题，并为Github创建了一组类似的问题。请避免以后再这样做，请花一些时间再开始提出新的问题/问题。