Where can I find a JPA2 Maven dependency?

问题:

I'm trying to build an implementation agnostic maven module which relies on JPA2. Unfortunately, the only Maven JPA dependency is JPA1 based, and consequently, I cannot use EntityManager.detach() method as that is a JPA2 option only.

Ideally, I'd love to be able to specify my javax.persistence dependency in my Pom, and require the app/container to supply the JPA2 implementation. Unfortunately, I cannot find any such dependency.

Is my only choice at this point to declare hibernate-jpa-2.0-api 1.0.0.FINAL as a provided dependency?

回答1:

The Hibernate JPA 2 classes (javax.persistence...) are here:

<dependency>
    <groupId>org.hibernate.javax.persistence</groupId>
    <artifactId>hibernate-jpa-2.0-api</artifactId>
    <version>1.0.1.Final</version>
</dependency>

回答2:

I know this is a quite old post, if you want to go agnostic from the implementation, then you should use the Java EE API dependency instead.

Just add to your POM:

<dependency>
    <groupId>javax</groupId>
    <artifactId>javaee-api</artifactId>
    <version>${jee.version}</version>
    <scope>provided</scope>
</dependency>

Where the ${jee.version} is your desired Java EE version. I'm currently using 7.0. It has all EJB, JPA and JSF APIs dependencies.

回答3:

I use the javax.persistence artifact (and not the eclipselink artifact) from the EclipseLink Maven repository to access the JPA 2 API classes. Snippets from POM include:

<project>
    ...
    <dependencies>
        ...
        <dependency>
            <groupId>org.eclipse.persistence</groupId>
            <artifactId>javax.persistence</artifactId>
            <version>2.0.0</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    ...
    <repositories>
        ...
        <repository>
            <id>EclipseLink Repo</id>
            <!-- note that ampersands in this URL are escaped because this is in an 
            xml file - un-escape them to use in browser -->
            <url>http://www.eclipse.org/downloads/download.php?r=1&amp;nf=1&amp;file=/rt/eclipselink/maven.repo</url>
        </repository>
    ...
    </repositories>
...
</project>

The javax.persistence artifact contains all the API classes, and none of the EclipseLink classes (except for two), allowing you to specify the scope as provided; this applies even for the EclipseLink JPA provider as well (which is in the eclipselink artifact Id).

I haven't mixed the javax.persistence artifact with the hibernate-entitymanager artifact, which is how I managed the dependency for another project that relies on Hibernate EntityManager instead of EclipseLink for the JPA provider. A snippet from the second project's POM is shown below:

<project>
    <dependencies>
    ...
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>3.6.5.Final</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>4.2.0.Final</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    ...
</project>

I do change the dependency scopes from provided to test in other projects to ensure that unit tests will have a JPA provider in the classpath. This is primarily done to mask out the side-effects of using the javaee-api dependency, which I use in the parent POM to allow compile time references to several Java EE 6 API classes.

回答4:

This are the most relevant and official API for JPA2 from EclipseLink:

<repositories>
    <repository>
        <url>http://download.eclipse.org/rt/eclipselink/maven.repo/</url>
        <id>eclipselink</id>
        <layout>default</layout>
        <name>Repository for library EclipseLink (JPA 2.0)</name>
    </repository>
</repositories>

<dependencies>
    <dependency>
        <groupId>org.eclipse.persistence</groupId>
        <artifactId>javax.persistence</artifactId>
        <version>2.0.3</version>
        <scope>provided</scope>
    </dependency>
</dependencies>

Unlike Hibernates API this are from official specification and support better generics when it comes to use Criteria API.

回答5:

For the JPA 2.2 API an "official" artifact is available from maven central, see this answer.

回答6:

As of today, I think the most up to date one is:

<dependency>                                          
    <groupId>org.hibernate.javax.persistence</groupId>
    <artifactId>hibernate-jpa-2.1-api</artifactId>    
    <version>1.0.0.Final</version>                    
</dependency>

This is how you can use JPA in a maven:

<dependency>
    <groupId>org.hibernate.javax.persistence</groupId>
    <artifactId>hibernate-jpa-2.1-api</artifactId>
    <version>1.0.0.Final</version>
    <scope>compile</scope>
</dependency>

<dependency>
    <groupId>javax.transaction</groupId>
    <artifactId>javax.transaction-api</artifactId>
    <version>1.2</version>
    <scope>compile</scope>
</dependency>

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-entitymanager</artifactId>
    <version>4.3.10.Final</version>
    <scope>runtime</scope>
    <exclusions>
        <exclusion>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.1-api</artifactId>
        </exclusion>
        <exclusion>
            <groupId>org.jboss.spec.javax.transaction</groupId>
            <artifactId>jboss-transaction-api_1.2_spec</artifactId>
        </exclusion>
        <exclusion>
            <groupId>xml-apis</groupId>
            <artifactId>xml-apis</artifactId>
        </exclusion>
        <exclusion>
            <groupId>org.jboss.logging</groupId>
            <artifactId>jboss-logging</artifactId>
        </exclusion>
    </exclusions>
</dependency>

回答7:

I was able to solve resolve my Maven JPA2 dependency by adding a couple of dependencies to the project's pom.xml file. See below for the xml code for the dependencies.
I found the latest groupId's and artifactId's versions by drilling down the directories out on Maven Central. I just walked the directory tree until I found the metadata.xml files for the persistence.core and the persistence.jpa artifacts.
Note: The dependency on persistence.jpa is what actually brings in the javax.persistence jar.

    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.2.1.Final</version>
        <scope>runtime</scope>
    </dependency>

    <dependency>
        <groupId>org.eclipse.persistence</groupId>
        <artifactId>org.eclipse.persistence.core</artifactId>
        <version>2.6.4</version>
        <scope>compile</scope>
    </dependency>

    <dependency>
        <groupId>org.eclipse.persistence</groupId>
        <artifactId>org.eclipse.persistence.jpa</artifactId>
        <version>2.6.4</version>
        <scope>compile</scope>
    </dependency>