Could not find any META-INF/persistence.xml file in the classpath, but i've added it

Question

I am trying to add JPA to my project, but always getting those errors:

keycloak_1   | 17:28:43,494 INFO  [org.hibernate.jpa.boot.internal.PersistenceXmlParser] (default task-2) HHH000318: Could not find any META-INF/persistence.xml file in the classpath
keycloak_1   | 17:28:43,495 ERROR [org.keycloak.services.error.KeycloakErrorHandler] (default task-2) Uncaught server error: javax.persistence.PersistenceException: No Persistence provider for EntityManager named SQL

But when i try to initialise my entity manager:

HashMap<String, String> properties = new HashMap<>();
properties.put("javax.persistence.jdbc.driver", configMap.getFirst(CONFIG_KEY_JDBC_URL));
properties.put("javax.persistence.jdbc.url", configMap.getFirst(CONFIG_KEY_JDBC_URL));
properties.put("javax.persistence.jdbc.user", configMap.getFirst(CONFIG_KEY_DB_USERNAME));
properties.put("javax.persistence.jdbc.password", configMap.getFirst(CONFIG_KEY_DB_PASSWORD));

EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory(
        "SQL",
        properties
);

EntityManager entityManager = entityManagerFactory.createEntityManager();

I am receiving those errors, but i can't understand how it's possible then i am clearly added that file to my .jar.

Persistence.xml content is :

<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_2.xsd"
             version="2.2">
    <persistence-unit name="SQL" transaction-type="RESOURCE_LOCAL">
        <properties>
            <property name="javax.persistence.jdbc.driver" value=""/>
            <property name="javax.persistence.jdbc.url" value=""/>
            <property name="javax.persistence.jdbc.user" value=""/>
            <property name="javax.persistence.jdbc.password" value=""/>
        </properties>
    </persistence-unit>
</persistence>

Structure of project and compiled jar is visible here (persistence content is changed to 2.2 version to mentioned before):

What am i doing wrong?

Update: Even find command returns that file exists in a correct directory:

➜  sql-sync-spi find . -type f -name "persistence.xml"
./build/resources/main/META-INF/persistence.xml
./src/main/resources/META-INF/persistence.xml

More updates: I've tried to copy persistence.xml from another project:

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0"
             xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="
        http://java.sun.com/xml/ns/persistence
        http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
    <persistence-unit name="user-storage-jpa-example">
        <jta-data-source>java:jboss/datasources/ExampleDS</jta-data-source>

        <class>org.keycloak.quickstart.storage.user.UserEntity</class>

        <properties>
            <property name="hibernate.hbm2ddl.auto" value="update" />
            <property name="hibernate.show_sql" value="false" />
        </properties>
    </persistence-unit>
</persistence>

And on service startup i've received fatal error:

07:03:02,188 ERROR [org.jboss.as.controller.management-operation] (Controller Boot Thread) WFLYCTL0013: Operation ("deploy") failed - address: ([("deployment" => "sql-sync-spi-1.0-SNAPSHOT.jar")]) - failure description: {
    "WFLYCTL0412: Required services that are not installed:" => ["jboss.naming.context.java.jboss.datasources.ExampleDS1"],
    "WFLYCTL0180: Services with missing/unavailable dependencies" => [
        "jboss.persistenceunit.\"sql-sync-spi-1.0-SNAPSHOT.jar#sql\".__FIRST_PHASE__ is missing [jboss.naming.context.java.jboss.datasources.ExampleDS]",
        "jboss.persistenceunit.\"sql-sync-spi-1.0-SNAPSHOT.jar#sql\" is missing [jboss.naming.context.java.jboss.datasources.ExampleDS1]"
    ]
}

So at least part of the project sure sees persistence.xml file and tries to read it. Then i've changed xml back to my settings, and again i have no error on startup but again no file exists in classpath on entity manager init attempt.

1. So it also is in the built jar (open the jar itself, 7zip or such)? 2. I assume you cleared the `value` attributes here (as one should!). — Joop Eggen, Aug 15 '21 at 20:35
Yes, if i "unzip" `sql-sync-spi-1.0-SNAPSHOT.jar` to `sql-sync-spi-1.0-SNAPSHOT` folder, then i can find persistence.xml in `sql-sync-spi-1.0-SNAPSHOT/META-INF/persistence.xml` (with find command, to ignore human mistake) — Itsmeromka, Aug 15 '21 at 20:51
IIUC, a Keycloak server is really just a WildFly server. [This project](https://github.com/keycloak/keycloak-quickstarts/tree/latest/user-storage-jpa) seems to be very similar to yours, only it uses Maven config. Note how dependencies are listed in `pom.xml`. The scope is `provided`. That's because the keycloak runtime *provides* them. In order to do the same with Gradle, see: https://stackoverflow.com/questions/18738888/how-to-use-provided-scope-for-jar-file-in-gradle-build — Janez Kuhar, Aug 15 '21 at 21:50
Yeap, i am actually copying many ideas from here, but stuck on adding entity manager because of persistance.xml problem. — Itsmeromka, Aug 15 '21 at 21:51
@JanezKuhar sadly your mentioned solution didn't help, it says to use "compileOnly group" when you are using "provided" scope, i've tried that and no luck. — Itsmeromka, Aug 16 '21 at 06:45

Janez Kuhar · Answer 1 · 2021-08-16T08:09:01.333

This is more of a comment than an answer since there's not enough room in the comment section and I haven't verified any of this.

First of all, I'd define a new DataSource on your Keycloak server. See: Relational Database Setup.

Your dependencies section of build.gradle should then look somewhat similar to:

dependencies {
    compileOnly 'org.keycloak:keycloak-server-spi'
    compileOnly 'org.keycloak:keycloak-common'
    implementation 'org.apache.commons:commons-lang3:3.12.0'
    compileOnly 'org.hibernate.javax.persistance:hibernate-jpa-2.1-api:1.0.0.Final'
    compileOnly 'org.jboss.spec.javax.ejb:jboss-ejb-api_3.2_spec:1.0.0.Final'

    compileOnly platform('org.wildfly.bom:wildfly-javaee8:14.0.1.Final')
    compileOnly platform('org.keycloak.bom:keycloak-spi-bom:15.0.1')
}

Your persistence.xml should change since we defined a DataSource on Keycloak:

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1"
    xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
    <persistence-unit name="yourDataSource">
        <jta-data-source>your_DS_name</jta-data-source>
        <!-- List your entities here. For example: -->
        <class>com.rmndbrvn.sqlsyncspi.UserEntity</class>
    </persistence-unit>
</persistence>

You can then get an instance to an EntityManager in your code like this:

@PersistenceContext(unitName = "yourDataSource")
EntityManager em;

Could not find any META-INF/persistence.xml file in the classpath, but i've added it

1 Answers1