CODEWITHSUNDEEP
javahibernatemavenjpa
maxenglander
maxenglander

Reputation: 4041

Hibernate error "unable to locate persister"

I am trying to execute some Java with the Maven exec plugin, and am getting an error Caused by: org.hibernate.UnknownEntityTypeException: Unable to locate persister: my.biz.CoolEntity. I tried a number of failed solutions, before ultimately finding a hacky fix. Based on the hacky fix, I believe the issue to be a runtime classpath error.

I am looking for an answer that will tell me how to address the problem without resorting to copying the needed files into place, as I do in the hacky fix.

Background

I have a Maven project "Project A" which has dependencies upon Hibernate 5.0.1.Final as well as another project "Project B". Project B contains my JPA entity classes, including my.biz.CoolEntity.

Normally, I build everything into a shaded JAR and run/deploy that, without any issues.

Hibernate issue

Recently, I began using Maven's exec:java goal, but am running into what on the surface is a Hibernate issue. when I run mvn exec:java -DmainClass=my.biz.CoolEntity, I get this error:

Caused by: org.hibernate.UnknownEntityTypeException: Unable to locate persister: my.biz.CoolEntity
        at org.hibernate.internal.SessionFactoryImpl.locateEntityPersister(SessionFactoryImpl.java:792) ~[hibernate-core-5.0.1.Fi
nal.jar:5.0.1.Final]
        at org.hibernate.internal.SessionImpl.locateEntityPersister(SessionImpl.java:2641) ~[hibernate-core-5.0.1.Final.jar:5.0.1
.Final]
        at org.hibernate.internal.SessionImpl.access$2500(SessionImpl.java:164) ~[hibernate-core-5.0.1.Final.jar:5.0.1.Final]
        at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.<init>(SessionImpl.java:2579) ~[hibernate-core-5.0.1.Final
.jar:5.0.1.Final]
        at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.<init>(SessionImpl.java:2566) ~[hibernate-core-5.0.1.Final
.jar:5.0.1.Final]
        at org.hibernate.internal.SessionImpl.byId(SessionImpl.java:1044) ~[hibernate-core-5.0.1.Final.jar:5.0.1.Final]
        at org.hibernate.internal.SessionImpl.get(SessionImpl.java:955) ~[hibernate-core-5.0.1.Final.jar:5.0.1.Final]
        at org.hibernate.jpa.spi.AbstractEntityManagerImpl.find(AbstractEntityManagerImpl.java:1075) ~[hibernate-entitymanager-5.
0.1.Final.jar:5.0.1.Final]

Failed attempts

I tried making use of the exec plugin's <additionalClasspathElements> and <includePluginDependencies>. The first solution didn't result in any different, and the second resulted in a compile-time error.

Hacky fix

What ended up working for me was copying the compiled classes from Project B into Project A.

Upvotes: 3

Views: 17333

Answers (5)

tom
tom

Reputation: 1493

In my case I was using Java 17 and a newer version of hibernate-core and trying to import javax.persistence.*. I started with this example and tried to upgrade hibernate-core to a newer version (6.2.7.Final) and got the error Unable to locate persister.

Original pom.xml:

    <dependencies>
        <dependency>
            <groupId>javax.persistence</groupId>
            <artifactId>javax.persistence-api</artifactId>
            <version>2.2</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate.orm</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>6.2.7.Final</version>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <version>2.1.214</version>
        </dependency>
    </dependencies>

Original imports:

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

The hibernate-core dependency pulls in persistence implicitly so explicitly pulling it in like that (and an older version) was my mistake. I just needed to change my pom dependencies to this:

    <dependencies>
        <dependency>
            <groupId>org.hibernate.orm</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>6.2.7.Final</version>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <version>2.1.214</version>
        </dependency>
    </dependencies>

And change my imports to this:

import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.Id;
import jakarta.persistence.Table;

... and it all worked fine after that.

Upvotes: 0

yoeltecleab
yoeltecleab

Reputation: 41

Try changing the imports from "javax" to "jakarta". I had the same issue and mine worked when I made the change.

Upvotes: 4

Kasun Siyambalapitiya
Kasun Siyambalapitiya

Reputation: 4393

I too got the same exception and it was due to missing the entity annotation @Entity for the class. Please check if the @Entity annotation is available in your class

Upvotes: 0

Lovish
Lovish

Reputation: 19

When we use Hibernate 5 jars, then we get

org.hibernate.UnknownEntityTypeException: Unable to locate persister".

I just changed the hibernate jar versions from 5 to 4 and then everything was fine. Hibernate 5 does not locate the entity classes even after mapping.

Upvotes: 0

ravthiru
ravthiru

Reputation: 9623

When the entities are residing in a different jar, you have to include it in persistence.xml. <jar-file>entities-packaged.jar</jar-file>. Different options are explained here

Upvotes: 1

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