Why does my Entity does not work with SpringBoot although it works without

问题

(Please note : while investigating on this issue I better spotted the source of problem that I introduce here)

I am very new to Hibernate and SpringBoot. My project deals with a search engine which indexing (javafx client) and searching (web client) parts are separated. The web client uses SpringBoot and during the process of the user's request, I need to retrieve information on the Solr Index to search against. These information are stored in a Hibernate / H2 local database where I use the following Entity class :

@Entity
@Table(name = "IndexSetups")
@Access(AccessType.PROPERTY)
public class IndexSetup {
 private final SimpleIntegerProperty id = new SimpleIntegerProperty();

 @Id
 @GeneratedValue(strategy = GenerationType.AUTO) // For H2 AUTO is required to auto increment the id
 public int getId() {
  return id.get();
}

 //... other properties, getters and setters

}

A LocalDatabase class features a method to list all IndexSetups from the DB (there are also other methods but focusing on this one is enough to understand the issue). I need to call it in a controller but I get a "Not an entity : class IndexSetup".

However the only way to use my Entity is to prevent the launching of SpringBoot (ie commenting the line starting with SpingApplication.run(...)) :

@SpringBootApplication
public class ServerApplication {

public static void main(String[] args) {
//      SpringApplication.run(ServerApplication.class, args); 

ArrayList<IndexSetup> availableSearchIndex = 
LocalDatabase.getInstance(false) // no GUI
            .getAllIndexSetups();

// The list is displayed as long as SpringApplication.run() call is commented. Otherwise "Not an entity"
System.err.println("The Index setups are " + availableSearchIndex); 
  }
}

Of course this is not a solution since I do need to process the user's request via Spring Boot :-D!

Finally the hibernate.cfg.xml file reads :

<hibernate-configuration>
  <session-factory>      
    <!-- Database connection settings -->
    <property name="connection.driver_class">org.h2.Driver</property>
    <!--The db file resides wihtin the parent project (so one level above the calling project see ../)-->
    <!--We use the auto server mode to be able to open the database from server and from indexer simultaneously
    see http://www.h2database.com/html/features.html#auto_mixed_mode -->
    <property name="connection.url">jdbc:h2:file:../MyAppDB;DB_CLOSE_ON_EXIT=TRUE;AUTO_SERVER=TRUE</property>
    <property name="connection.username">test</property>
    <property name="connection.password"/>
    <!-- JDBC connection pool (use the built-in) -->
    <property name="connection.pool_size">1</property>
    <!-- SQL dialect -->
    <property name="dialect">org.hibernate.dialect.H2Dialect</property>
    <!-- Disable the second-level cache -->
    <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>
    <!-- Echo all executed SQL to stdout -->
    <property name="show_sql">false</property>
    <!-- Updates the existing database schema on startup -->
    <property name="hbm2ddl.auto">update</property>
    <!-- The mapping information of entities -->
    <mapping class="my.package.Entities.IndexSetup"/>
 </session-factory>
</hibernate-configuration>

The stack trace is :

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:498)
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)

Caused by: java.lang.IllegalArgumentException: Not an entity: class my.package.Entities.IndexSetup
at org.hibernate.metamodel.internal.MetamodelImpl.entity(MetamodelImpl.java:457)
at org.hibernate.query.criteria.internal.QueryStructure.from(QueryStructure.java:126)
at org.hibernate.query.criteria.internal.CriteriaQueryImpl.from(CriteriaQueryImpl.java:153)
at my.package.LocalDatabase.getAllIndexSetups(LocalDatabase.java:99)
at my.package.ServerApplication.main(ServerApplication.java:15)

And I've just noticed those two lines printed by Spring Boot at startup :

2018-10-15 11:47:46.208  INFO 27730 --- [  restartedMain] org.hibernate.cfg.Environment            : HHH000206: hibernate.properties not found // Maybe this one is not just "INFO"
2018-10-15 11:47:46.591  WARN 27730 --- [  restartedMain] org.hibernate.orm.connections.pooling    : HHH10001002: Using Hibernate built-in connection pool (not for production use!)
2018-10-15 11:47:46.594  INFO 27730 --- [  restartedMain] org.hibernate.orm.connections.pooling    : HHH10001005: using driver [org.h2.Driver] at URL [jdbc:h2:file:../MyAppDB;DB_CLOSE_ON_EXIT=TRUE;FILE_LOCK=NO] // Just to show that my bibernate.cfg.xml is found

It looks unlikely to be a dependency problem as it only stops working when Spring application is run.

So my question is : what should I do to make my Entity work within SpringBoot ?

Any help much appreciated!

回答1:

Add @EntityScan to ServerApplication.class.

@EntityScan (org.springframework.boot.autoconfigure.domain.EntityScan) identifies which classes should be used by a specific persistence context.

来源：https://stackoverflow.com/questions/52813610/why-does-my-entity-does-not-work-with-springboot-although-it-works-without

标签

java

hibernate

spring-boot