spring boot data jpa无法连接mysql数据库

Question

我尝试使用spring-boot-starter-data-jpa 连接到mysql，并通过this example 休眠，但是得到了

...
2016-07-28 13:20:49.021 错误 7765 --- [main] os.boot.SpringApplication：应用程序启动失败 org.springframework.beans.factory.BeanCreationException：错误 用名字创建bean 'org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration'： 注入自动装配的依赖项失败；嵌套异常是 org.springframework.beans.factory.BeanCreationException：不能 自动装配字段：私有 javax.sql.DataSource org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.dataSource； 嵌套异常是 org.springframework.beans.factory.BeanCreationException：错误 创建在类路径资源中定义的名称为“dataSource”的bean [org/springframework/boot/autoconfigure/jdbc/DataSourceAutoConfiguration$NonEmbeddedConfiguration.class]： 通过工厂方法实例化 Bean 失败；嵌套异常是 org.springframework.beans.BeanInstantiationException：失败 实例化 [javax.sql.DataSource]：工厂方法 'dataSource' 抛出 例外;嵌套异常是 org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException： 无法确定数据库类型的嵌入式数据库驱动程序类 没有。如果您想要一个嵌入式数据库，请放置一个受支持的数据库 类路径。如果您有要从 您可能需要激活它的特定配置文件（没有配置文件是 当前活跃）

...

application.properties：

    # DataSource settings: set here your own configurations for the database 
# connection. In this example we have "netgloo_blog" as database name and 
# "root" as username and password.
spring.datasource.url = jdbc:mysql://localhost:3306/db
spring.datasource.username = db
spring.datasource.password = pass

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

# Keep the connection alive if idle for a long time (needed in production)
spring.datasource.testWhileIdle = true
spring.datasource.validationQuery = SELECT 1

# Show or not log for each sql query
spring.jpa.show-sql = true

# Hibernate ddl auto (create, create-drop, update)
spring.jpa.hibernate.ddl-auto = update

# Naming strategy
spring.jpa.hibernate.naming-strategy = org.hibernate.cfg.ImprovedNamingStrategy

# Use spring.jpa.properties.* for Hibernate native properties (the prefix is
# stripped before adding them to the entity manager)

# The SQL dialect makes Hibernate generate better SQL for the chosen database
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect

eclipse中的项目结构：

build.gradle：

 buildscript {
  repositories {
        mavenCentral()
  }
  dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-  plugin:1.3.6.RELEASE")
  }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'spring-boot'

jar {
    baseName = 'gs-accessing-data-jpa'
    version =  '0.1.0'
}

repositories {
    mavenCentral()
    maven { url "https://repository.jboss.org/nexus/content/repositories/releases" }
}

sourceCompatibility = 1.8
targetCompatibility = 1.8

dependencies {
    compile("org.springframework.boot:spring-boot-starter-data-jpa")
    compile group: 'org.springframework.boot', name: 'spring-boot-starter-web', version: '1.3.6.RELEASE'
    compile group: 'mysql', name: 'mysql-connector-java', version: '6.0.3' 

   //also tried

    runtime group: 'mysql', name: 'mysql-connector-java', version: '6.0.3' 
    runtime "org.apache.tomcat:tomcat-jdbc:7.0.47"

    testCompile("junit:junit")
}

task wrapper(type: Wrapper) {
    gradleVersion = '2.3'
}

Answer 1

你没有添加驱动类

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

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

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

同时检查这些依赖项

Answer 2

你可以在 gradle 中添加运行时依赖，而不是在 MYSQL Driver jar 上添加编译时依赖吗？

dependencies {
  //compile "mysql:mysql-connector-java:6.0.3"
  runtime "mysql:mysql-connector-java:6.0.3"
  runtime "org.apache.tomcat:tomcat-jdbc:7.0.47"
}

Answer 3

类路径上有数据库驱动程序吗？ 你设置了属性spring.datasource.driver-class-name吗？

有关详细信息，请参阅 http://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-sql.html