Using Hibernate reverse engineering creates mappingResources style but I need annotatedClasses - java

Using Hibernate reverse engineering creates mappingResources style but I need annotatedClasses.
Anyway to make "Hibernate reverse engineering" to make the code annotatedClasses style and not mappingResources style?
I am trying to take a large mySQL database and make java classes with annotated in them.
Please let me know if anyone has done this

You can achieve that with Hibernate Tools, an Eclipse plugin.
Take a look at this tutorial. Every steps are explains. When you are generating the .java files, you can choose between xml file and JPA annotations.
To generate annotations, check Generate EJB3 annotations and Use Java 5 syntax

First you need to add the annotations support to the dependencies of your project. It depends on the version of hibernate do you use. As for the hibernate 4 annotations already included in the core jar, however make sure hibernate-commons-annotations included also. Then the reverse engineering wizard will let you choose how do you want to map the generated classes.

Related

How to perform Hibernate Reverse Engineering in Eclipse IDE version 2020-09

I was trying to use reverse engineering in hibernate in the latest Eclipse IDE but all the resources I came across seem to be outdated.
would appreciate it if I get some input as to how to go about this procedure.
I tried the steps in this link (https://www.codejava.net/frameworks/hibernate/java-hibernate-reverse-engineering-tutorial-with-eclipse-and-mysql )but was not able to generate the Entity classes with the annotations. This method generated a POJO with no annotations at all.
Would be thankful if I find a way to solve this problem.
You have to tick this check box in order to generate EJB3 annotations

How to generate model from database

I have an existing database. I need to generate the model classes in Java from it. Are there any tool/library that will allow me to do this. It will be of great help if it can emulate the entity relationships in the database into the model classes as well.
It is acceptable if the tool/library works with only one database vendor. I will create a database there and then generate the model.
Thanks in advance.
EDIT : I will probably use Hibernate as the ORM framework if I manage to generate the model.
The Hibernate Tools project (available as an Eclipse plug-in, as well as an Ant task) allows for "reverse-engineering" of database schemas into appropriate entity classes.
This project is also available in the JBoss Tools project.
The facility allows for reverse-engineering of the database metadata into a Hibernate configuration file. All artifacts (including the .java files) are generated from this config file.
You can control the nature of the reverse engineering process to suit your database structure. In other words, you can specify the schemas that you wish to have the tool reverse-engineer. You could also override the JDBC type mapping, apart from limiting the reverse-engineering process to a selected set of tables.
Obligatory link:
Screencast on Reverse engineering and code generation
Telosys does exactly this job
Let's have a look : http://www.telosys.org/
Minuteproject 4 JPA2 (http://minuteproject.wikispaces.com/JPA2) track does this task.
Minuteproject can be run from console or command line.
You can have a quick result by generating from the console where generate a maven project containing the JPA2 mapping classes in java or groovy.
If you use the command line then you need to fill an xml file that can contain additional customisation of your generated code such as packaging, enum, aliasing etc...
You can also try other track built on top JPA2 such as DAO with spring or EJB; REST; front end with Primefaces or Openxava; etc...
Hibernate has an Eclipse plugin Hibernate Tools http://www.hibernate.org/subprojects/tools.html that has reverse engineering capabilities.
See: http://docs.jboss.org/tools/3.2.0.GA/en/hibernatetools/html/plugins.html#refeng_codegen for more details on how to run and customize the reverse engineering process.

IntelliJ IDEA Hibernate

I'm learning hibernate and I am running into some issues. I'm reading "Harnessing Hibernate" by O'Reilly. They explain everything using ANT, but since I want to avoid writing a huge build.xml file, I'm trying to get it to work with IntelliJ.
I managed to make a mapping according to a DB table in a MySQL database, and wrote the bean for it. It worked, but I can't find any information on how to generate beans and SQL code, or how to reverse engineer with IntelliJ. I found loads of tutorials about Eclipse, using JBOSS Hibernate tools plugin, and the site claims this support for generating code is already in the standard installation of IntelliJ.
Am I forgetting some configuration such as adding libraries? I'm trying to find this out but I'm desperate now. Please don't suggest me to use Eclipse, I need IntelliJ for my current role.
AFAIK, IntelliJ IDEA includes the complete JPA/Hibernate support in its Ultimate Edition:
Generating Persistence Mappings from Database Schema
IntelliJ IDEA allows you to quickly
generate persistence mappings from any
database schema: Generating
Persistance Mappings
(source: jetbrains.com)
Now, the question is, what edition of Intellij IDEA are you using?
If you add the hbm2ddl to your Hibernate config and ask it to create the database schema you'll get it by running a single test or some other code that exercises Hibernate. Once you have it, turn off create.
Let Hibernate do the work.

Hibernate Tools - DAO generation

I am using the eclipse hibernate tools plug-in to reverse engineer my database.
I spent my whole day looking for how to force the DAO generator to use HQL/Criteria with the session factory, transaction, etc.
Right now, if I have the table TABLE in my database, I obtain the DAO class TableHome. This class uses the persistence EntityManager.
I found tutorials using an older version of hibernate tools generating TableDAO instead, and this is what I exactly need.
Thank you very much.
Whether you're using Eclipse or not is unclear but if you are, maybe check if the Console Configuration used by the Code Generation module is not configured for JPA:
alt text http://docs.jboss.org/tools/2.1.0.Beta1/hibernatetools/html/images/plugins/plugins_2.png
See also
Section 3.4. Creating a Hibernate Console Configuration
Section 3.5. Reverse Engineering and Code Generation
Use Salto-DB Eclipse plugin. It comes with all the stuff.

How to generate JPA mapping file from the JPA annotated entity classes?

I am using openjpa runtime of JPA specification.
At development time I am using annotations to configure jpa entities.
At Integration, Pre-Production and and Production environment, I am using orm mapping files to configure entities. Please suggest a tool which can generate mapping files from jpa annotations, so that these mapping files can be manually edited for different environment.
If there is already a opensource maven-plugin; will be great.
I don't really know OpenJPA so there is maybe a better way to do this but one option would be to first generate the XML schema file from annotated entities using the Schema Tool and then the orm.xml file from the schema.xml using the Reverse Mapping Tool. Actually, this process is discussed in this thread.
I've checked the OpenJPA Maven Plugin but it doesn't seem to support the Reverse Mapping part (it only has a openjpa:schema goal that allows to Create a file which contains the schema mapping XML, the first required operation, but nothing for the second part). Extending the plugin to add the missing openjpa:reverse-mapping goal would thus require some development but it shouldn't be an hard task.
There is another option though. OpenJPA provides the following Ant tasks for both operations:
org.apache.openjpa.jdbc.ant.ReverseMappingToolTask
org.apache.openjpa.jdbc.ant.SchemaToolTask
So it should be possible to call them from Maven using the Maven AntRun Plugin. Check the documentation for more details on how to use them.

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