无法使用Java连接到MySQL

Question

三天来，我一直在寻找答案，却找不到我的问题的确切答案。因此，我正在做一些关于Spring和Hibernate的教程，并且在尝试在Spring项目、MySQL数据库和Tomcat服务器之间建立连接时陷入困境。这是我的"pom.xml“文件：

<?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>com.bookstore</groupId>
    <artifactId>bookstore</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>Bookstore</name>
    <description>frontend part for our bookstore project</description>

    <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>1.4.3.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>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
      </dependency>
    </dependencies>

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

​

这是我的财产：

spring.thymeleaf.cache=false

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

# Set here configurations for the database connection
spring.datasource.url=jdbc:mysql://localhost:3306/bookstoredatabase?autoReconnect=true&useSSL=false

# Username and secret
spring.datasource.username=root
spring.datasource.password=target

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

# ===============================
# = JPA / HIBERNATE
# ===============================

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

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

# Hibernate ddl auto (create, create-drop, update): with "update" the database
# schema will be automatically updated accordingly to java entities found in
# the project
spring.jpa.hibernate.ddl-auto = update

# Allows Hibernate to generate SQL optimized for a particular DBMS
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect

我正在使用XAMPP-7.0.56版的Tomcat。MySQL服务器和连接器都是版本8。如果不使用Tomcat，我完全可以连接到任何数据库，编辑它等等。

以下是发生的错误：

INFO 15816 --- [main] org.hibernate.Version: HHH000412: Hibernate Core {5.0.11.Final}
INFO 15816 --- [main] org.hibernate.cfg.Environment: HHH000206: hibernate.properties not found
INFO 15816 --- [main] org.hibernate.cfg.Environment: HHH000021: Bytecode provider name:javassist
INFO 15816 --- [main] o.hibernate.annotations.common.Version: HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
ERROR 15816 --- [main] o.a.tomcat.jdbc.pool.ConnectionPool: Unable to create initial connections of pool. com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.

完整的错误日志可以看到这里。我试过很多东西。请帮帮我伙计们。

编辑：好的。我已经更仔细地阅读了错误日志。我正在使用XAMPP版本7.056中的Tomcat，但是Spring使用版本8启动Tomcat。

Answer 1

对不起。我现在查过了。

当您检查错误报告时，可能是在连接器/J5.1.41中修复的。

将此更改为pom.xml

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.15</version>
</dependency>

Answer 2

您在mysql上创建了名为bookstoredatabase的数据库吗？我认为您应该在pom.xml中添加mysql连接器的依赖项。

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