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Designing Hibernate classes with tables

I'm new to hibernate and trying to understand what is the correct way to implement and use it.
Creates tables and then use a tool to generate Hibernate classes
or
Build the classes and create the tables
Our's is a legacy application, so the tables structure is already there..We are just creating the Hibernate classes and using them...
Can someone let me know which is correct and effecient way?

You have automated tools for both sides.
create the classes from a legacy database:
you should use this if you have a runnig database already.netbeans have one of these.
create the tables and relations from entity and embedded clasess:
this way you have to use anotations or a xml file to describe the relations betwen clases and other relational stuff and set table generation strategy to create in the persistence unit the tables will be created automatically usigng the names of the classes for the table and the names of the fields for the columns.
If you already have the database use the tool to generate entity classes

If you use Eclipse then here is a tool to generate POJOs from existing tables:
step by step auto code generation using eclipse plugin
If you are using Intellij check out Intellij Java Persistence API & Hibernate

Generate Entities in Hibernate

I have to develop a java web application. For persistence, I am going to use hibernate.
I am a symfony2 developer and I like generating my entities using Doctrine 2 console.
So is there a similar tool for hibernate (or other well known Java ORM) that generates entities automatically ?

AFAIK, no, there are no entity generators on par with the ones in doctrine or rails.
However generating entities from existing tables can still be quite comfortable if you use eclipse. Take a look at this help page . The page itself is a bit outdated, but the functionality is still there. The menus will guide you nicely through property and relation mapping.
Other IDEs like IntelliJ and NetBeans probably have similar tools, but I am not familiar enough with them to advise.

You can use hibernate reverse engineering tool(Hibernate Tool) to generate Entity classes. What you need to do is to provide session factory configuration(it takes your hibernate.cfg.xml) and database schema.

Can Hibernate tool generate JPA POJO?

May I know can the Eclipse plugin Hibernate tool use to generate JPA entity #entity? The Java files that generated look like below and not JPA:
package com.test.only.model;
// Generated Jul 19, 2011 12:13:40 PM by Hibernate Tools 3.2.0.CR1
import java.math.BigDecimal;
import java.util.Date;
/**
* Account generated by hbm2java
*/
public class Account implements java.io.Serializable {

You just need to choose EJB3 + Java5 as configuration options when generating.
Learn more: http://docs.jboss.org/tools/4.0.0.Final/en/hibernatetools/html_single/index.html#jpa_annotations

I believe you can generate Hibernate annotation code by using the Hibernate Perspective -> Add Configuration… and follow the steps of this tutorial .
I suspect the JPA annotated entity can be generated if you select JPA(jdk 1.5+) or Annotation (jdk 1.5+) in the following configuration .Please try it.

Yes, it can.
Hibernate Tools, which is now available as a part of JBoss Tools, can be used for generating JPA entities as well. In fact you need to select JPA option in Hibernate Configuration which is being used for your project.
Even better would be to start off your reverse code generation as a JPA Project. Then once the project is created switch over to the Hibernate Perspective to confirm the JPA annotations option is selected in the Hibernate Configuration settings.
Following tutorial has pictorial representation of various steps involved in creating a JPA Project in Eclipse. It then shows in the Appendix section how to edit the Hibernate Configuration as well.
http://www.javabrahman.com/j2ee/how-to-setup-a-jpa-project-with-a-data-connection-for-mysql-in-eclipse/

For me changing from hibernate version 5.4 to 5.2 worked while configuring.
and do check use Java5 syntax and Generate EJB3 annotations while code generation.

Hibernate tool to create basic mappings based on a mysql db

Are there any tools that can look at a database, and generate the basic mapping files?
It would be great if it could take a database, and create the actual model (java classes) with annotations, but not sure if that exists?

Hibernate 3 has a toolset called Hibernate Tools that provides an Eclipse plugin and an Ant task that both support Reverse Engineering:
Reverse Engineering: The most powerful feature of Hibernate Tools is a database reverse engineering tool that can generate domain model classes and Hibernate mapping files, annotated EJB3 entity beans, HTML documentation or even an entire JBoss Seam application in seconds!
...
Ant task: The Hibernate3 tools include a unified Ant task that allows you to run schema generation, mapping generation, or Java code generation as part of your build.
For the Eclipse plugin, have a look at this section of the documentation. For the Ant task, have a look at the section about reverse engineering and optionally how to control it.
Note that other IDEs also provide support for reverse engineering (see Hibernate Reverse Engineering for Netbeans 6.5 and Generating Persistence Mappings from Database Schema for IntelliJ).

I just happened to stumble across this problem and I think I have found a perfect tool for the job.
http://hibernatepojoge.sourceforge.net/
Features : (in case you are lazy to go through the provided link)
Java objects representing each table using annotations for use with Hibernate.
A JUnit test case per table that uses the objects generated to create, populate, save, retrieve and compare results
DAO per class
The appropriate enumeration files
Spring and hibernate configuration
DAO layers
A data factory class per schema to return a pre-populated object with random data (for boundary checking, database population, etc)
Also supports:
Join tables including those with additional fields in link tables
Polymorphism/inheritance support
Composite Keys
One-To-One, many-to-one, many-to-many, etc
Multiple schema support (4 modes)
Natural Keys
Enumerations (including those entries which cannot be mapped cleanly onto the java world)
A whole bunch of more stuff (see sample.xml)
I would also like to say that setting this up is quite straight forward; You just have to have a hibernate configuration file and the jar file downloaded from the site. Then it's just a matter executing a jar file, passing the config.xml as a parameter!

If you are using eclipse or ant...
Jboss tools

You might find what you need here, I found it on the fly: MyGeneration.
I know there are others that exist, but I don'T remember by heart. Hope this helps!

generate java domain objects from database table

may i know in eclipse, is there any feature that will auto generate domain objects with all table relationship properly mapped in class?
can provide me with some reference articles on this?

You can use something like Hibernate to accomplish this
This plugin set for Eclipse called Hibernate Tools for Eclipse and ANT will do most of the work for you.
In particular it will do Reverse Engineering: The most powerful feature of Hibernate Tools is a database reverse engineering tool that can generate domain model classes and Hibernate mapping files, annotated EJB3 entity beans, HTML documentation or even an entire JBoss Seam application in seconds!

Telosys code generator does this kind of job.
It's an Eclipse plugin, it uses the database schema to create a light model
that is used to generate the Java code.
There are some predefined templates available on GitHub (for JPA, POJO, Documentation, Spring MVC, etc )
See http://www.telosys.org
and http://marketplace.eclipse.org/content/telosys-tools
Templates : https://github.com/telosys-templates-v3
Articles about code generation with Telosys :
https://modeling-languages.com/telosys-tools-the-concept-of-lightweight-model-for-code-generation/
https://dzone.com/articles/telosys-a-code-generation-tool-by-laurent-guerin

You can use Hibernate Tools 3.0.0.GA either via Eclipse or ANT to auto-generate your hibernate domain entities directly from your database tables.
See tutorial here :
http://docs.jboss.org/tools/3.0.0.GA/en/hibernatetools/html_single/index.html

I have a solution for you i.e to create auto generate domain objects with all table relationship properly mapped in class ...Try Dal4j yes you can find it in sourceforge.net/p/dal4j/wiki/ DAL4j is a Command Line and Framework tool that can be used to reverse engineer a MySQL or SQLServer database schema into a set of JPA Entity Beans.
DAL4j can be useful for scenarios where there is an existing database schema but a technology other that JPA is used by applications to interact with the database. DAL4j can provide an easy way to migrate your code base from other technologies such as JDBC or Hibernate to JPA.
The beans generated can be 1 or two types: Simple or Framework. Simple beans are standard pojo classes managed by your application using JPA semantics. Framework generated pojos use the DAL4j framework DAO generic to simplify CRUD operations.
DAL4j provides optional hooks to allow you integrate encryption/decryption of data fields that must be encrypted in the database.
Last, DAL4j provides a set of Generic classes that can be used to simplify creation of Session Beans which perform CRUD operations using generated Entities.
I think you will find this article feasible....

You want an object relational mapping of which Hibernate is the most popular for Java. The hibernate tools are typically better for taking annotated classes and using them to generate a schema, as opposed to vice versa, which is what you sound like you're doing. I suspect you'll be doing a lot of hand-annotating if you're working with a legacy DB schema.

if you use grails, you can generate domain objects with GRAG http://sourceforge.net/projects/grag

I use eclipse for java development, but when it comes to generating domain entities I use Net beans.
Create an EJB module, and then right click and generate entities.
You need to set up the database also you can select the tables you want visually.
Regards
Lyju

It feels like another rather common question that people always run into.
The link below links to a blog detailed enough for me to learn how to generate entities from database schema the first time.
http://shengwangi.blogspot.com/2014/12/how-to-create-java-classes-from-tables.html
Just in case, the following link refers to eclipse help page. This link should never expire:
http://help.eclipse.org/juno/index.jsp?topic=%2Forg.eclipse.jpt.doc.user%2Ftasks021.htm
I downloaded JBoss and failed to understand how it works. I think the plugin that I used is Hibernate Tools but I am not sure as I did not install any new plugin for this purpose. I am using Eclipse Luna for EE.
Hope this helps.

I got so tired of manually coding this kind of stuff so I made a tool to generate models, dao, and dao implementation from a schema. It's oriented towards spring boot and only tested on MySQL, but for those that don't want to use Hibernate and just want to work with jdbc/sql and JdbcTemplate, or just want POJOs with getter/setters generated for tables, then this could perhaps be something to kick off the coding.
Called Jassd (Java Automated Spring Source-code for Databases generator), I'm "jazzed" to introduce this tool: https://github.com/aforslund/jassd