使用hibernate以编程方式验证架构

这是一个解决方案,如果您的用例需要:

• 颗粒状&显式控制架构的哪一部分应为
• 需要验证多个模式
• 需要验证服务未使用的模式,定时验证器正在该服务上运行
• 应用程序使用的db连接不应以任何方式受到验证的影响(也就是说,您不想从主连接池借用连接)

如何执行计划架构验证的示例 :

@SpringBootApplication
@EnableScheduling
@EnableConfigurationProperties(ScheamValidatorProperties.class)
public class SchemaValidatorApplication {
     public static void main(String[] args) {
       SpringApplication.run(SchemaValidatorApplication.class, args);
    }
}

@ConfigurationProperties("schema-validator")
class ScheamValidatorProperties {
    public Map<String, String> settings = new HashMap<>();

    public ScheamValidatorProperties() {
    }

    public Map<String, String> getSettings() { 
        return this.settings;
    }

    public void setSome(Map<String, String> settings) { 
        this.settings = settings;
    }
}

@Component
class ScheduledSchemaValidator {

    private ScheamValidatorProperties props;

    public ScheduledSchemaValidator(ScheamValidatorProperties props) {
        this.props = props;
    }

    @Scheduled(cron = "0 0/1 * * * ?")
    public void validateSchema() {
        StandardServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
            .applySettings(props.getSettings())
            .build();

        Metadata metadata = new MetadataSources(serviceRegistry)
            .addAnnotatedClass(Entity1.class)
            .addAnnotatedClass(Entity2.class)
            .buildMetadata();

        try {
            new SchemaValidator().validate(metadata, serviceRegistry);
        } catch (Exception e) {
            System.out.println("Validation failed: " + e.getMessage());
        } finally {
            StandardServiceRegistryBuilder.destroy(serviceRegistry);
        }
    }
}

@Entity
@Table(name = "table1")
class Entity1 {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    Entity1() {}

    public Long getId() {
        return id;
    }

}

@Entity
@Table(name = "table2")
class Entity2 {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    Entity2() {}

    public Long getId() {
        return id;
    }
}

CREATE DATABASE IF NOT EXISTS testdb;

CREATE TABLE IF NOT EXISTS `table1` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (`id`)
);

CREATE TABLE IF NOT EXISTS `table2` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (`id`)
);

3. application.yml

spring:
  cache:
    type: none
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3309/testdb?useSSL=false&nullNamePatternMatchesAll=true&serverTimezone=UTC&allowPublicKeyRetrieval=true
    username: test_user
    password: test_password
    testWhileIdle: true
    validationQuery: SELECT 1
  jpa:
    show-sql: false
    database-platform: org.hibernate.dialect.MySQL8Dialect
    hibernate:
      ddl-auto: none
      naming:
        physical-strategy: org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy
        implicit-strategy: org.springframework.boot.orm.jpa.hibernate.SpringImplicitNamingStrategy
    properties:
      hibernate.dialect: org.hibernate.dialect.MySQL8Dialect
      hibernate.cache.use_second_level_cache: false
      hibernate.cache.use_query_cache: false
      hibernate.generate_statistics: false
      hibernate.hbm2ddl.auto: validate

schema-validator:
    settings:
        connection.driver_class: com.mysql.cj.jdbc.Driver
        hibernate.dialect: org.hibernate.dialect.MySQL8Dialect
        hibernate.connection.url: jdbc:mysql://localhost:3309/testdb?autoReconnect=true&useSSL=false&allowPublicKeyRetrieval=true
        hibernate.connection.username: test_user
        hibernate.connection.password: test_password
        hibernate.default_schema: testdb

4. docker-compose.yml

version: '3.0'

services:
  db:
    image: mysql:8.0.14
    restart: always
    ports:
     - 3309:3306
    environment:
      MYSQL_ROOT_PASSWORD: test_password
      MYSQL_DATABASE: testdb
      MYSQL_USER: test_user
      MYSQL_PASSWORD: test_password

SchemaValidator 要重用已经在项目中配置的连接配置和映射信息,而不是再次定义它们来进行模式验证,那么您应该考虑我的解决方案,这样您就可以干了,不需要在两个不同的地方维护这些配置。

图式发生器 Metadata 实例,该实例仅在引导休眠期间可用。但是我们可以使用Hibernate Integrator API(如中所述) here

SchemaValidateService 它实现了Hibernate Integrator API来捕获 元数据 . 还设置了一个 @Scheduled 方法在所需时间验证架构。

@Component
public class SchemaValidateService implements Integrator {

    private Metadata metadata;

    @Override
    public void integrate(Metadata metadata, SessionFactoryImplementor sessionFactory,
            SessionFactoryServiceRegistry serviceRegistry) {
        this.metadata = metadata;
    }

    @Override
    public void disintegrate(SessionFactoryImplementor sessionFactory, SessionFactoryServiceRegistry serviceRegistry) {
    }

    //Adjust the scheduled time here
    @Scheduled(cron = "0 0/1 * * * ?")
    public void validate() {
        try {
            System.out.println("Start validating schema");
            new SchemaValidator().validate(metadata);
        } catch (Exception e) {
            //log the validation error here.
        }
        System.out.println("Finish validating schema....");
    }
}

@SpringBootApplication
@EnableScheduling
public class App {

    @Bean
    public HibernatePropertiesCustomizer hibernatePropertiesCustomizer(SchemaValidateService schemaValidateService) {
        return (prop -> {
            List<Integrator> integrators = new ArrayList<>();
            integrators.add(schemaValidateService);
            prop.put("hibernate.integrator_provider", (IntegratorProvider) () -> integrators);
        });
    }
}

此外,此解决方案应该具有更好的性能,因为它不需要每次都创建新的数据库连接来验证模式,因为它可以从现有连接池中获取连接。