spring boot數據jpa無法連接到mysql數據庫

Question

我嘗試使用spring-boot-starter-data-jpa和hibernate通過這個例子連接到mysql，但得到

...
2016-07-28 13：20：49.021 ERROR 7765 --- [main] osboot.SpringApplication：應用程序啟動失敗org.springframework.beans.factory.BeanCreationException：創建名為'org.springframework.boot.autoconfigure.orm的bean時出錯.jpa.HibernateJpaAutoConfiguration'：自動連接依賴項的注入失敗; 嵌套異常是org.springframework.beans.factory.BeanCreationException：無法自動裝配字段：private javax.sql.DataSource org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.dataSource; 嵌套異常是org.springframework.beans.factory.BeanCreationException：在類路徑資源中定義名為'dataSource'的bean時出錯[org / springframework / boot / autoconfigure / jdbc / DataSourceAutoConfiguration $ NonEmbeddedConfiguration.class]：通過工廠方法進行Bean實例化失敗; 嵌套異常是org.springframework.beans.BeanInstantiationException：無法實例化[javax.sql.DataSource]：工廠方法'dataSource'拋出異常; 嵌套異常是org.springframework.boot.autoconfigure.jdbc.DataSourceProperties $ DataSourceBeanCreationException：無法確定數據庫類型為NONE的嵌入式數據庫驅動程序類。 如果你想要一個嵌入式數據庫，請在類路徑上放置一個受支持的數據庫。 如果您要從特定配置文件加載數據庫設置，則可能需要激活它（當前沒有配置文件處於活動狀態）

...

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

日食中的項目結構：

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

您沒有添加驅動程序類

spring.datasource.driver類名= 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>

檢查這些依賴項

Answer 2

你可以在gradle中添加運行時依賴，而不是在MYSQL驅動程序jar上編譯時依賴嗎？

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

你在類路徑上有數據庫驅動程序嗎？ 你有設置屬性spring.datasource.driver-class-name ？

有關更多詳細信息，請參閱http://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-sql.html