Hibernate - moving annotations from property (method) level to field level

Question

How do I generate hibernate domain classes from tables with annotations at field level? I used Hibernate Tools project and generated domain classes from the tables in the da

Answer 1

I spent a lot of time reading answers from 5+ years ago without understanding how to do it (especially if you work in Intellij and not Eclipse) and how come this is not already solved. So i found it, here it is, and it is simple:

In Intellij:

1. Create a file orm.xml in the same folder as your persistence.xml with this content

<?xml version="1.0" encoding="UTF-8"?>
    <entity-mappings xmlns="http://java.sun.com/xml/ns/persistence/orm"
                     version="2.0">
        <persistence-unit-metadata>
            <persistence-unit-defaults>
                <access>FIELD</access>
            </persistence-unit-defaults>
        </persistence-unit-metadata>
    </entity-mappings>

2. Now you can generate your pojos (Generate persistence mapping -> By database schema -> choose your tables etc and don't forget to tick the "Generate JPA Annotations")

Your entities will have field annotations!

@Entity
@Table(name = "user", schema = "public", catalog = "my_db")
public class User {
    @Id
    @Column(name = "id")
    private Integer id;
...
}

Answer 2

Here are the steps:

1. Allocate "hibernate-tools.jar" by perform a search within your eclipse folder For example, You will find it at C:\eclipse\plugins\org.hibernate.eclipse_3.4.1.xxx\lib\tools

2. Extract to a temp folder (WinRar can do this) For example, extract to [Your Project]\template

3. Under [Your Project]\template\pojo folder, create a file named "Ejb3FieldGetAnnotation.ftl"

   This file is actually a copy of "Ejb3PropertyGetAnnotation.ftl" but all of words "property" are replaced by "field" because this file will be placed in the a loop that iterates through all fields (instead of properties). I include the content of the file in this post

4. Remove property-level annotations: In file "PojoPropertyAccessors.ftl", remove or comment out

   <#include "GetPropertyAnnotation.ftl"/>
   

5. Add field-level annotations: In file "PojoFields.ftl", add

   <#include "Ejb3FieldGetAnnotation.ftl"/>
   ${pojo.getFieldModifiers(field)} ... 
   

6. When generate Java entities, select "Use Custom Templates" and specify the template folder. In this case, it will be [Your Project]\template

   ==================================================================================
   Ejb3FieldGetAnnotation.ftl
   ==================================================================================
   
   <#if ejb3>
   <#if pojo.hasIdentifierProperty()>
   <#if field.equals(clazz.identifierProperty)>
    ${pojo.generateAnnIdGenerator()}
   <#-- if this is the id property (getter)-->
   <#-- explicitly set the column name for this property-->
   </#if>
   </#if>
   
   <#if c2h.isOneToOne(field)>
   ${pojo.generateOneToOneAnnotation(field, cfg)}
   <#elseif c2h.isManyToOne(field)>
   ${pojo.generateManyToOneAnnotation(field)}
   <#--TODO support optional and targetEntity-->    
   ${pojo.generateJoinColumnsAnnotation(field, cfg)}
   <#elseif c2h.isCollection(field)>
   ${pojo.generateCollectionAnnotation(field, cfg)}
   <#else>
   ${pojo.generateBasicAnnotation(field)}
   ${pojo.generateAnnColumnAnnotation(field)}
   </#if>
   </#if>
   

Hope it work for you.

Answer 3

currently it is necessary to use custom templates. here is more references and examples hot to implement this: https://forum.hibernate.org/viewtopic.php?f=6&t=1003858&p=2429868#p2429868