无法在 Spring Boot 应用程序中加载驱动程序类：org.h2.Driver

Question

我正在尝试通过创建一个虚拟项目来学习微服务。我在 git 中有一个配置存储库和一个在端口 8888 上运行的配置服务器。它工作正常，因为我可以看到我的设置如下：

现在我有两个微服务项目 1）客户服务和 2）客户帐户服务。客户微服务正常运行，而客户帐户微服务无法启动并抛出以下异常：

*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.h2.Driver
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.0.11.RELEASE.jar:5.0.11.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:583) ~[spring-beans-5.0.11.RELEASE.jar:5.0.11.RELEASE]
    ... 66 common frames omitted
Caused by: java.lang.IllegalStateException: Cannot load driver class: org.h2.Driver
    at org.springframework.util.Assert.state(Assert.java:94) ~[spring-core-5.0.11.RELEASE.jar:5.0.11.RELEASE]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceProperties.determineDriverClassName(DataSourceProperties.java:224) ~[spring-boot-autoconfigure-2.0.7.RELEASE.jar:2.0.7.RELEASE]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceProperties.initializeDataSourceBuilder(DataSourceProperties.java:176) ~[spring-boot-autoconfigure-2.0.7.RELEASE.jar:2.0.7.RELEASE]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceConfiguration.createDataSource(DataSourceConfiguration.java:43) ~[spring-boot-autoconfigure-2.0.7.RELEASE.jar:2.0.7.RELEASE]
    at org.springframework.boot.autoconfigure.jdbc.DataSourceConfiguration$Hikari.dataSource(DataSourceConfiguration.java:83) ~[spring-boot-autoconfigure-2.0.7.RELEASE.jar:2.0.7.RELEASE]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_144]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_144]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_144]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_144]
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.0.11.RELEASE.jar:5.0.11.RELEASE]
    ... 67 common frames omitted*

customer-account-microservice 的 bootstrap.properties 配置如下：

customer-account-microservice 的 pom.xml 配置如下：

<?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>2.0.7.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.microservice</groupId>
    <artifactId>customer-account-microservice</artifactId>
    <version>1</version>
    <name>customer-account-microservice</name>
    <description>Spring starter project for demonstrating spring feign client and circuit breaker</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud-services.version>2.0.3.RELEASE</spring-cloud-services.version>
        <spring-cloud.version>Finchley.SR2</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.7.0</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.7.0</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>io.pivotal.spring.cloud</groupId>
            <artifactId>spring-cloud-services-starter-circuit-breaker</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.h2database</groupId>
                <artifactId>h2</artifactId>
                <scope>runtime</scope>
            </dependency>
            <dependency>
                <groupId>io.pivotal.spring.cloud</groupId>
                <artifactId>spring-cloud-services-dependencies</artifactId>
                <version>${spring-cloud-services.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

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

</project>

请帮助我解决上述异常。

Answer 1

看来你的依赖

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <scope>runtime</scope>
</dependency>

必须在dependencies元素中，而不是在dependencyManagement. 看看这个。或者，也许您有一个子工件，在这种情况下，您必须共享另一个 pom xml。

Answer 2

就我而言，“司机”后面有一个空格

spring.datasource.driverClassName=org.h2.Driver...

我删除了它并且运行得很好

Answer 3

即使在pom.xml. 它归结为 IDE 特定问题，即无法下载h2依赖项。重启IDE后就可以了。

Answer 4

我将其更改为“编译”并解决了我的问题。

        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <version>1.4.200</version>
            <scope>compile</scope>
        </dependency>

Answer 5

就我而言，问题是由 application.properties 中驱动程序类名后面的一些尾随空白字符引起的

这会失败（下面代码片段中的点应被读取为空白字符）：

spring.datasource.driverClassName=org.h2.Driver...

这成功了：

spring.datasource.driverClassName=org.h2.Driver