Hibernate Reverse Engineering Process

1. Hibernate
reverse engineering
José Luis Muñoz
Jun 17, 2012

2. Contents
1
1. Hibernate view
2. Create a “new hibernate configuration”
3. Hibernate Reverse Engineering: hibernate.reveng.xml
4. Hibernate code generation configuration
5. Reverse engineering
6. Retrieve objects List
7. Example using Session.get

3. Hibernate view
2
Choose the correct view
Window > Show View > Hibernate configurations

4. Hibernate view
3
Click on Hibernate

5. Hibernate view
4
Click on Open Perspective; this open a dialog box

6. Create a “new hibernate configuration”
5
Goal:
connect Eclipse with the Data Base using a Hibernate bridge
Eclipse Hibernate
Hibernate.cfg.xml
Data Base

7. Create a “new hibernate configuration”
6
- Hibernate configuration tab, at the bottom
- Right bottom
- Add configuration
* This name is the same that is going to be used in the code generation configuration

8. Create a “new hibernate configuration”
7
Project: folder where is located the project
Database connection: Hibernate configured
Configuration file: folder where is located hibernate configuration file (fileName.cfg.xml)

9. Create a “new hibernate configuration”
8
Options Tab
Database dialect: MySQL

10. Create a “new hibernate configuration”
9
Classpath Tab
Classpath: you must include hibernate libraries into the path

11. Create a “new hibernate configuration”
10
Result

12. Hibernate Reverse Engineering: hibernate.reveng.xml
11

13. Hibernate Reverse Engineering: hibernate.reveng.xml
12
Goal:
Create a file where is specified the number of tables used to obtained:
- POJOs (plain java objects with attributes and getter/setter methods)
- hbm.xml (mapping files which maps data base fields into class attributes)

14. Hibernate Reverse Engineering: hibernate.reveng.xml
13
File > New > Hibernate Reverse Engineering File (reveng.xml)

15. Hibernate Reverse Engineering: hibernate.reveng.xml
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Parent Folder: must be selected the project folder

16. Hibernate Reverse Engineering: hibernate.reveng.xml
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1. Console configuration: choose the configuration created in step 1
2. Refresh (until a data base schema appears at the left box)
3. Click Include: include every table in the data base
3. Click Finish button
* The image above must be obtained as a result of applying the indicated steps

17. Result
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* This file specified the tables contained within the data base which must be mapped

18. 17
Goal:
Create a configuration to obtain:
When you run the configuration are created:
- POJOs
- hmb.xml
- Change in hibernate.cfg.xml
- DAO object related to POJOs
Hibernate code generation configuration

19. Hibernate code generation configuration
18
Run option

20. Hibernate code generation configuration
19
New Configuration
Console configuration: the same name configured in step 1

21. Hibernate code generation configuration
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New Configuration
Revenge.xml: the file generated before

22. Hibernate code generation configuration
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New Configuration
General settings: use Java 5 syntax
Exporters: at least one file exporter

23. 22
Goal:
Create a configuration to obtain:
When you run the configuration are created:
- POJOs
- hmb.xml
- Change in hibernate.cfg.xml
- DAO object related to POJOs
Hibernate code generation configuration

24. Result: hibernate.reveng.xml
* This file match every table contained within the data base
* This file match just employee table contained within the data base

25. hibernate.reveng.xml
* This file match just employee table contained within the data base.
* The result has effect int the hibernate.cfg.xml changing the number of .hbm files.
Be careful:

26. hibernate.reveng.xml
* This file match the schema
* NO RESULTS
Be careful !!

27. 26
Goal:
Used the hibernate main files to retrieve and save object without SQL:
- POJOs
- hmb.xml
- DAO object related to POJOs
Retrieve objects List

28. 27
Method used: getEmployeeExample
- First of all we need to configure a Session Factory in order to obtain a Session
Retrieve objects List

29. 28
We obtain a list of objects, though a casting those are converted to Employees
Retrieve objects List

30. 29
We obtain one object and though a casting is converted into an Employee
Example using Session.get

31. 30
Example using Session.get
We obtain one object and though a casting is converted into an Employee

32. The End
31
joseluis@trustparency.es