我有一个访问被拒绝的例外：
java.sql.sqlexception:拒绝用户“”@'localhost'（使用密码：no）org.springframework.jdbc.support.metadataaccessexception:无法获取用于提取元数据的连接；嵌套异常为org.springframework.jdbc.cannotgetjdbcconnectionexception:获取jdbc连接失败；嵌套异常为java.sql.sqlexception:拒绝用户''@'localhost'（使用密码：no）018-08-23 00:55:21.791 info 1260---[main]j.localcontainerentitymanagerfactorbean:为持久性单元'default'构建jpa容器entitymanagerfactory 2018-08-23 00:55:21.813 info 1260---[main]o、 hibernate.jpa.internal.util.loghelper:hhh000204:正在处理persistenceunitinfo[名称：默认…]2018-08-23 00:55:22.180信息1260---[main]org.hibernate.version
：hhh000412:hibernate核心{5.2.17.final}2018-08-23 00:55:22.181信息1260---[main]org.hibernate.cfg.environment
：hhh000206:hibernate.properties not found 2018-08-23 00:55:22.221 info 1260---[main]o.hibernate.annotations.common.version:hcann000001:hibernate commons annotations{5.0.1.final}2018-08-23 00:55:22.351 info 1260---[main]com.zaxxer.hikari.hikaridatasource:hikaripol-1-正在启动。。。2018-08-23 00:55:23.445错误1260---[main]com.zaxxer.hikari.pool.hikaripool:hikaripool-1-池初始化期间出现异常。
应用程序属性文件：

spring.thymeleaf.cache=false

    #===============================
    #DATA SOURCE
    #===============================

    #set here configurations for the database connection

    spring.datasource.url=jdbc:mysql://localhost:3306/bookstoredatabase?verifyServerCertificate=false&useSSL=true
    #username and secret
    spring.datasource.data.username=root
    spring.datasource.data.password=

    #keep connection alive if idle for long time
    spring.datasource.testWhileIdle = true
    spring.datasource.validationQuery = SELECT 1

    #===================
    #jpa/hibernate
    #===================
    #use spring.jpa.properties.* for hibernate native properties
    #stripped before adding them to the entity manager

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

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

    #the project
    spring.jpa.hibernate.ddl-auto=create

    #allows hibernate to generat sql optimised for particular dbms
    spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect

我的java文件：

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class BookstoreApplication {

    public static void main(String[] args) {
        SpringApplication.run(BookstoreApplication.class, args);
    }
}