java - 加载驱动类 com.mysql.jdbc.Driver 失败

Question

我正在尝试使用两个配置文件运行我的 Spring Boot 后端，一个使用内存数据库中的 H2，第二个使用 MySQL。 H2 数据库工作得很好，但是当我切换到 MySQL 时，我得到了

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

Description:

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

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

Action:

Update your application's configuration

我尝试删除 .m2、重新导入、清理 maven、编译、安装以及我在互联网上可以找到的大部分内容，但都没有成功。有趣的是，我有其他项目只使用 MySQL 数据库，我有类似的问题，但添加 mysql-connector-java 依赖项解决了它。我现在不知道。

application.properties

spring.profiles.active=@profilename@

#H2 in memory database
domain.datasource.type=H2
domain.datasource.url=jdbc:h2:mem:store;MODE=MYSQL;
domain.datasource.driver-class=org.h2.Driver
domain.datasource.username=sa
domain.datasource.password=
domain.datasource.generate-dll=true

application-local_mysql.properties

spring.profiles.active=@profilename@

#MySQL local database
domain.datasource.type=MYSQL
domain.datasource.url=jdbc:mysql://localhost:3600/store;
domain.datasource.driver-class=com.mysql.jdbc.Driver;
domain.datasource.username=store
domain.datasource.password=store
domain.datasource.generate-dll=false

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>

    <groupId>sk.personal</groupId>
    <artifactId>my-project</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>my-project</name>
    <description>My personal project.</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
            <version>2.0.5.RELEASE</version>
        </dependency>

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

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

        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>

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

    </dependencies>

    <profiles>
        <profile>
            <id>local_h2</id>
            <properties>
                <profilename>local_h2</profilename>
            </properties>
            <activation>
                <activeByDefault>true</activeByDefault>
            </activation>
        </profile>
        <profile>
            <id>local_mysql</id>
            <properties>
                <profilename>local_mysql</profilename>
                <maven.test.skip>true</maven.test.skip>
            </properties>
        </profile>
    </profiles>

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

DatasourceConfig.java

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseBuilder;
import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType;

import javax.sql.DataSource;

@Configuration
public class DatasourceConfig {

    @Value("${domain.datasource.url}")
    private String url;

    @Value("${domain.datasource.username}")
    private String username;

    @Value("${domain.datasource.password}")
    private String password;

    @Value("${domain.datasource.type}")
    private String type;

    @Value("${domain.datasource.driver-class}")
    private String driverClass;

    @Bean
    public DataSource dataSource() {
        if (type.equals("MYSQL")) {
            return DataSourceBuilder
                    .create()
                    .username(username)
                    .password(password)
                    .url(url)
                    .driverClassName(driverClass)
                    .build();
        } else {
            EmbeddedDatabaseBuilder builder = new EmbeddedDatabaseBuilder();
            return builder
                    .setType(EmbeddedDatabaseType.H2)
                    .build();
        }
    }
}

Answer 1

在我的例子中，缺少下一个依赖项:

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

在使用 IntelliJ 的情况下，如果您继承自 <parent> ，您可以查看您的有效pom.xml右键单击 pom.xml 中的任意位置， 然后:

并搜索 mysql-connector-java提到的工件。