Spring Boot: Hibernate and Flyway boot order

问题:

I have created Spring application. Pom xml is attached.

It has a config like this (below) and some db/migration/V1__init.sql for Flyway db migration tool.

It has hsqldb in-memory database and it is created after application is started. It is clean after creation.

I want Hibernate to create a schema based on entity classes and then Flyway fills the tables. Now Flyway starts V1__init.sql before tables is created and throw an exception. How can I change this order or what solution can I do?

spring.datasource.testWhileIdle = true
spring.datasource.validationQuery = SELECT 1
spring.jpa.show-sql = true
spring.jpa.hibernate.ddl-auto = create-drop
spring.jpa.hibernate.naming-strategy = org.hibernate.cfg.ImprovedNamingStrategy
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.HSQLDialect

pom.xml:

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.3.3.RELEASE</version>
    <relativePath/>
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java.version>1.8</java.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <version>1.3.2.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.hsqldb</groupId>
        <artifactId>hsqldb</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>4.3.11.Final</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
        <version>4.2.5.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.thymeleaf</groupId>
        <artifactId>thymeleaf-spring4</artifactId>
        <version>2.1.4.RELEASE</version>
    </dependency>

    <!-- For using 'LEGACYHTML5' mode in Thymeleaf -->
    <dependency>
        <groupId>net.sourceforge.nekohtml</groupId>
        <artifactId>nekohtml</artifactId>
        <version>1.9.21</version>
    </dependency>
    <dependency>
        <groupId>xml-apis</groupId>
        <artifactId>xml-apis</artifactId>
        <version>1.4.01</version>
    </dependency>

    <dependency>
        <groupId>org.flywaydb</groupId>
        <artifactId>flyway-core</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
        <version>1.3.3.RELEASE</version>
    </dependency>
</dependencies>

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

回答1:

I had the same issue.

I wanted my schema to be created by hibernate because of it's database independence. I already went through the trouble of figuring out a nice schema for my application in my jpa classes, I don't like repeating myself.

But I want some data initialization to be done in a versioned manner which flyway is good at.

Spring boot runs flyway migrations before hibernate. To change it I overrode the spring boot initializer to do nothing. Then I created a second initializer that runs after hibernate is done. All you need to do is add this configuration class:

import org.flywaydb.core.Flyway;
import org.springframework.boot.autoconfigure.flyway.FlywayMigrationInitializer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.DependsOn;

@Configuration
public class MigrationConfiguration {


    /**
     * Override default flyway initializer to do nothing
     */
    @Bean
    FlywayMigrationInitializer flywayInitializer(Flyway flyway) {
        return new FlywayMigrationInitializer(flyway, (f) ->{} );
    }


    /**
     * Create a second flyway initializer to run after jpa has created the schema
     */
    @Bean
    @DependsOn("entityManagerFactory")
    FlywayMigrationInitializer delayedFlywayInitializer(Flyway flyway) {
        return new FlywayMigrationInitializer(flyway, null);
    }


}

That code needs java 8, If you have java 7 or earlier, replace (f)->{} with an inner class that implements FlywayMigrationStrategy

Of course you can do this in xml just as easily.

Make sure to add this to your application.properties:

flyway.baselineOnMigrate = true

回答2:

Spring Boot auto-configuration of Flyway ensures that database migrations have run before Hibernate is initialised. In other words, you can't rely on Flyway auto-configuration and use Flyway to populate tables created by Hinernate.

One solution is to fully embrace Flyway and use it to both create the tables and populate them. You can then switch off Hibernate's table creation (spring.jpa.hibernate.ddl-auto=none). This approach is more robust as it will allow your database to evolve more easily. This is what I would recommend that you do.

Another solution is to disable auto-configuration of Flyway (flyway.enabled=false) and to configure it your self. You can then configure Flyway to depend on Hibernate so that Hibernate has created the tables before Flyway tries to populate them.

回答3:

I have resolved my task. I have removed Flyway and just added data.sql