使用Spring Boot和Hibernate时，与MariaDB的连接是否自动关闭？

Question

我有一个连接到MariaDB数据库的Spring Boot应用程序，在我意识到存在到数据库的非托管连接之前，它一直运行良好。依赖关系是使用Maven管理的。我试图使用$mysql-u root-p登录数据库，但被告知连接太多。我的印象是Spring框架自动关闭了与数据库的连接。Spring/Hibernate如何管理到MariaDB的连接？

    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
            <groupId>org.mariadb.jdbc</groupId>
            <artifactId>mariadb-java-client</artifactId>
            <version>1.1.9</version>
        </dependency>
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-search-engine</artifactId>
            <version>5.6.1.Final</version>
            <exclusions>
                <exclusion>
                    <groupId>org.jboss.logging</groupId>
                    <artifactId>jboss-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-search-orm -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-search-orm</artifactId>
            <version>5.6.1.Final</version>
            <exclusions>
                <exclusion>
                    <groupId>org.jboss.logging</groupId>
                    <artifactId>jboss-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

来自应用程序.属性：

spring.datasource.username=root
spring.datasource.password=example-password

spring.datasource.driver-class-name=org.mariadb.jdbc.Driver
# Keep the connection alive if idle for a long time (needed in production)
spring.datasource.testWhileIdle=true
spring.datasource.validationQuery=SELECT 1
# ===============================
# = JPA / HIBERNATE
# ===============================
# Show or not log for each sql query
spring.jpa.show-sql=true
# Hibernate ddl auto (create, create-drop, update): with "create-drop" the database
# schema will be automatically created afresh for every start of application
spring.jpa.hibernate.ddl-auto=validate
# Naming strategy
spring.jpa.hibernate.naming.implicit-strategy=org.hibernate.boot.model.naming.ImplicitNamingStrategyLegacyHbmImpl
spring.jpa.hibernate.naming.physical-strategy=org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy
# Allows Hibernate to generate SQL optimized for a particular DBMS
<<<<<<< HEAD
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
=======
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
>>>>>>> 353345d141a2f83e8155574a9c8bbc04805ee1ee

当尝试登录到mysql服务器时，我收到错误消息：“太多连接”。

类似地，如果我现在尝试使用Maven运行应用程序，我会收到：

无法构建Hibernate SessionFactory；嵌套异常为org.hibernate.exception.GenericJDBCexception：无法打开执行DDL的JDBC连接：连接太多

Answer 1

如果您在每个请求中打开到数据库的会话，那么您必须在完成事务后关闭它，如下所示。

Session mSession = mSessionFactory.openSession();

...

mSession.close();