spring-boot-devtools dependency breaks hibernate with mysql 5.7

[zgulde]

Including the spring-boot-devtools and hibernate in the same project breaks hibernate with MySQL with the following exception:

Exception in thread "restartedMain" java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)
Caused by: org.hibernate.PropertyAccessException: Could not set field value [5] value by reflection : [class com.example.SomeTable.id] setter of com.example.SomeTable.id
	at org.hibernate.property.access.spi.SetterFieldImpl.set(SetterFieldImpl.java:58)
	at org.hibernate.tuple.entity.AbstractEntityTuplizer.setIdentifier(AbstractEntityTuplizer.java:259)
	at org.hibernate.persister.entity.AbstractEntityPersister.setIdentifier(AbstractEntityPersister.java:4667)
	at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:87)
	at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:623)
	at org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:277)
	at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:258)
	at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:303)
	at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:318)
	at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:275)
	at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:182)
	at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:113)
	at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192)
	at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)
	at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177)
	at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)
	at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)
	at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:674)
	at org.hibernate.internal.SessionImpl.save(SessionImpl.java:666)
	at org.hibernate.internal.SessionImpl.save(SessionImpl.java:661)
	at com.example.DevtoolsHibernateBugApplication.main(DevtoolsHibernateBugApplication.java:19)
	... 5 more
Caused by: java.lang.IllegalArgumentException: Can not set long field com.example.SomeTable.id to com.example.SomeTable
	at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167)
	at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171)
	at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:58)
	at sun.reflect.UnsafeLongFieldAccessorImpl.set(UnsafeLongFieldAccessorImpl.java:75)
	at java.lang.reflect.Field.set(Field.java:764)
	at org.hibernate.property.access.spi.SetterFieldImpl.set(SetterFieldImpl.java:38)
	... 25 more

see sample application PR

When the spring-boot-devtools dependency is removed, everything works as intended.

Please let me know if I can provide any additional information.

MySQL version

mysql Ver 14.14 Distrib 5.7.16, for osx10.10 (x86_64) using EditLine wrapper

Java version

java version "1.8.0_102"
Java(TM) SE Runtime Environment (build 1.8.0_102-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.102-b14, mixed mode)

The following is a minimal bug reproduction

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>com.example</groupId>
	<artifactId>devtools-hibernate-bug</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>devtools-hibernate-bug</name>
	<description>minimal reproduction of spring boot devtools - hibernate clash</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.0.BUILD-SNAPSHOT</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-data-jpa</artifactId>
		</dependency>
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
			<scope>runtime</scope>
		</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>
	<repositories>
		<repository>
			<id>spring-snapshots</id>
			<name>Spring Snapshots</name>
			<url>https://repo.spring.io/snapshot</url>
			<snapshots>
				<enabled>true</enabled>
			</snapshots>
		</repository>
		<repository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</repository>
	</repositories>
	<pluginRepositories>
		<pluginRepository>
			<id>spring-snapshots</id>
			<name>Spring Snapshots</name>
			<url>https://repo.spring.io/snapshot</url>
			<snapshots>
				<enabled>true</enabled>
			</snapshots>
		</pluginRepository>
		<pluginRepository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</pluginRepository>
	</pluginRepositories>
</project>

hibernate.cfg.xml

<?xml version="1.0"?>
<!DOCTYPE
        hibernate-configuration
        PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"
        >
<hibernate-configuration>
    <session-factory>
        <property name="connection.driver_class">
            com.mysql.jdbc.Driver
        </property>
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

        <property name="connection.url">
            jdbc:mysql://localhost/test_db?createDatabaseIfNotExist=true
        </property>
        <property name="connection.username">root</property>
        <property name="connection.password">pass</property>
        <property name="show_sql">true</property>
        <mapping class="com.example.SomeTable"/>
    </session-factory>
</hibernate-configuration>

application.properties

spring.datasource.url=jdbc:mysql://localhost/test_db?createDatabaseIfNotExist=true
spring.datasource.username=root
spring.datasource.password=pass
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.hibernate.ddl-auto=update

SomeTable.java

package com.example;

import javax.persistence.*;

@Entity
@Table(name = "some_table")
public class SomeTable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;
}

DevtoolsHibernateBugApplication.java

package com.example;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DevtoolsHibernateBugApplication {
	public static void main(String[] args) {
		SpringApplication.run(DevtoolsHibernateBugApplication.class, args);

		Session session = getSessionFactory().openSession();
		Transaction tx = session.beginTransaction();
		session.save(new SomeTable());
        tx.commit();
    }

    private static SessionFactory getSessionFactory() {
        StandardServiceRegistry registry = new StandardServiceRegistryBuilder()
            .configure()
            .build();

        return new MetadataSources(registry)
            .buildMetadata()
            .buildSessionFactory();
    }
}

[wilkinsona]

I am not entirely surprised that your example causes a problem as you are working with Hibernate in your application's main method, rather than in a component that's managed by Spring. Does the problem still occur if that logic is performed in a Spring-managed bean?

[zgulde]

Putting the logic in the main method was just my attempt at creating a minimal bug reproduction.

I'm fairly new to the spring framework, so I could very well be using the framework the wrong way, let me know if that is the case.

That being said, moving the logic to live inside a CommandLineRunner component does not solve the problem. The same exception is present and similarly, removing the devtools dependency solves it.

Updated the issues sample project pull request to reflect this change.

[snicoll]

Thanks for the sample, very helpful.

That's a rather unusual Hibernate setup for Spring Boot. There is a full duplication of your datasource settings in hibernate.cfg.xml and I am not surprised you get that issue: that devtools issue happens because you are bootstraping the session factory behind Spring Boot's back.

If you really have to use Hibernate like that (i.e. access to the SessionFactory), perhaps you could get it via the JPA support instead? I am sure your project is more complicated but, I removed the hibernate.cfg.xml and retrieved the SessionFactory differently and it worked:

@Component
public class BugReproduction implements CommandLineRunner {
	private final SessionFactory sessionFactory;

	public BugReproduction(EntityManagerFactory entityManagerFactory) {
		this.sessionFactory = entityManagerFactory.unwrap(SessionFactory.class);
	}

	public void run(String... args) {
        Session session = this.sessionFactory.openSession();
        Transaction tx = session.beginTransaction();
        session.save(new SomeTable());
        tx.commit();
    }
}

[zgulde]

Excellent, that helps me out a lot, thank you!