spring boot data jpa can't connect to mysql database
<p>I try to connect to mysql using <code>spring-boot-starter-data-jpa</code> and hibernate by <a href="http://blog.netgloo.com/2014/10/27/using-mysql-in-spring-boot-via-spring-data-jpa-and-hibernate/" rel="nofollow noreferrer">this example</a> but get </p>

<blockquote>
  <p>...<br>
  2016-07-28 13:20:49.021 ERROR 7765 --- [           main] o.s.boot.SpringApplication               : Application startup failed
  org.springframework.beans.factory.BeanCreationException: Error
  creating bean with name
  'org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration':
  Injection of autowired dependencies failed; nested exception is
  org.springframework.beans.factory.BeanCreationException: Could not
  autowire field: private javax.sql.DataSource
  org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.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/DataSourceAutoConfiguration$NonEmbeddedConfiguration.class]:
  Bean instantiation via factory method failed; nested exception is
  org.springframework.beans.BeanInstantiationException: Failed to
  instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw
  exception; nested exception is
  org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException:
  Cannot determine embedded database driver class for database type
  NONE. If you want an embedded database please put a supported one on
  the classpath. If you have database settings to be loaded from a
  particular profile you may need to active it (no profiles are
  currently active)</p>
  
  <p>...</p>
</blockquote>

<p>application.properties:</p>

<pre><code>    # 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
</code></pre>

<p>project structure in eclipse:</p>

<p><a href="https://i.stack.imgur.com/vLYbN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vLYbN.png" alt="enter image description here"></a></p>

<p>build.gradle :</p>

<pre><code> 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'
}
</code></pre>