Example JPA Static MetaModel

https://docs.jboss.org/hibernate/orm/5.0/topical/html/metamodelgen/MetamodelGenerator.html

Configuration

For main and test dirs: cp application.properties.dist application.properties

Installation

Add deps:

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-jpamodelgen</artifactId>
    <version>5.3.2.Final</version>
</dependency>

Add build plugin:

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.7.0</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
                <encoding>UTF-8</encoding>
                <compilerArguments>
                    <processor>org.hibernate.jpamodelgen.JPAMetaModelEntityProcessor</processor>
                </compilerArguments>
            </configuration>
        </plugin>
    </plugins>
</build>

Run package: mvn package

See dir: /target/classes/hello/entity/oneToMany/Author_.class

Config Intellij

File--Settings--Build--Compiler--Annotation Processors

• Enable Annotation Processor
• Obtain processors for project classpath
• Production source directory: target/generated-sources/annotations
• Test source directory: target/generated-test-sources/test-annotations
• Annotation processor: add: org.hibernate.jpamodelgen.JPAMetaModelEntityProcessor
• Apply

After then run maven from intellij

Using

Old - without static metaModel:

    CriteriaQuery<Comment> criteriaQuery = getCriteriaQuery();
    Root<Comment> root = getRoot(criteriaQuery);
    criteriaQuery.select(root);
    
    Join<Comment, Post> joinPost = root.join("post");
    criteriaQuery.where(getCriteriaBuilder().equal(joinPost.get("id"), postId));
    
    return getSession()
            .createQuery(criteriaQuery)
            .getResultList();

New - with static metaModel:

    CriteriaQuery<Comment> criteriaQuery = getCriteriaQuery();
    Root<Comment> root = getRoot(criteriaQuery);
    criteriaQuery.select(root);

    Join<Comment, Post> joinPost = root.join(Comment_.post);
    criteriaQuery.where(getCriteriaBuilder().equal(joinPost.get(Post_.id), postId));

    return getSession()
            .createQuery(criteriaQuery)
            .getResultList();