Spring Boot+Hibernate+MySQL无法创建池的初始连接

Question

下面是我从Internet上的大多数教程中复制的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>my.com.froggy</groupId>
    <artifactId>froggy</artifactId>
    <version>0.0.1</version>
    <packaging>jar</packaging>

    <name>demo</name>
    <description>My Project</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.1.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-web</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.1-api</artifactId>
            <version>1.0.0.Final</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
        </dependency>
    </dependencies>

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


</project>

然后，下面是我放置在属性文件中的配置：

spring.datasource.url = jdbc:mysql://127.0.0.1/test 
spring.datasource.username = root 
spring.datasource.password = 

spring.jpa.hibernate.ddl-auto = create-drop

spring.datasource.testWhileIdle = true 
spring.datasource.timeBetweenEvictionRunsMillis = 60000 
spring.datasource.validationQuery = SELECT 1

我会犯什么错？我得到以下错误：

2016-09-25 22:58:18.297信息8452---[main]org.Hibernate.version:hhh000412:Hibernate核心{5.0.11.final}2016-09-25 22:58:18.299信息8452---[
main]org.Hibernate.cfg.environment:hhh000205:已从资源Hibernate.properties加载属性：{spring.datasource.username=root,spring.datasource.testwhileidle=true,spring.datasource.timeBetweenevictionRunsMillis=60000,泳池。

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException：通信链接失败

2016-09-25 22:58:19.708警告8452-[main]O.H.E.J.E.I.JDBCEnvironmentInitiator:HHH000342:无法获取查询元数据的连接：通信链接失败

最后一个成功发送到服务器的数据包是在0毫秒前。驱动程序没有从服务器接收到任何数据包。2016-09-25 22:58:19.711警告8452-[main]ationConfigEmbeddedWebApplicationContext：上下文初始化过程中遇到异常-取消刷新尝试：org.springFramework.Beans.Factory.BeanCreationException：创建类路径资源[org/springFramework/boot/autociguration/orm/jpa/hibernatejpaAutoConfiguration.class]中定义的名为“Entity ManagerFactory”的bean时出错：调用init方法失败；嵌套异常为org.hibernate.service.spi.ServiceException：无法创建请求的服务[org.hibernate.engine.jdbc.env.spi.jdbcEnvironment]2016-09-25 22:58:19.714信息8452--[main]o.apache.catalina.core.StandardService：停止服务Tomcat 2016-09-25 22:58:19.726信息8452--[main]utoConfigurationReportLoggingInitializer:

启动ApplicationContext时出错。若要显示自动配置报告，请在启用“debug”的情况下重新运行应用程序。2016-09-25 22:58:19.729错误8452-[main]O.S.Boot.SpringApplication：应用程序启动失败

Answer 1

首先确保安装了MYSQL。如果已安装，请确保将其配置为端口3306。此外，如果它仍然没有连接，请确保您的密码和名称输入正确。看来您没有在application.properties中为用户名root提供密码。

spring.datasource.url=jdbc:mysql://localhost:3306/yourdb
spring.jpa.hibernate.ddl-auto=update
spring.datasource.username=root
spring.datasource.password=12345

并确保首先手动创建了该数据库。