This document provides an overview and agenda for a presentation on code recipes using various Jakarta EE APIs. It discusses getting started with Eclipse GlassFish or Payara and incorporating Jakarta EE specifications into projects. It then presents problems and solutions demonstrating the Jakarta RESTful Web Services, JSON-B, JSON Patch, Concurrency APIs and more. Code examples are provided on GitHub for consuming, processing and displaying RESTful data across frontend, service and database tiers.

1. Jakarta EE Recipes
Code Smarter
Josh Juneau
Apress and Oracle Author
JCP Member, Apache NetBeans Contributor,
Java Champion

2. About Me
Josh Junea
u
- Java EE and Jakarta EE Develope
r
- Oracle DB
A
- Author (Apress and Oracle
)
-Apache NetBeans PM
C
- Java Champio
n
- "Off Heap" and "Stackd" Podcasts

3. Agenda
Code-driven overview of some Jakarta E
E
API
s
- Utilize a number of Jakarta EE API
s
- Demonstrate useful techniques from the
APIs

4. How to Get Started
Today
• Download Eclipse GlassFish 6,Utilize Payara 5.x for JDK
11+ support w Eclipse Transformer support, OR
download another compatible containe
r
• 5.2021.8 -> This presentatio
n
• https://projects.eclipse.org/projects/ee4j.glass
fi
s
h
• Incorporate the speci
fi
cations into your projec
t
• Obtain a Maven Archetype or use starter
• https://search.maven.org/artifact/io.github.juneau001/
• https://start.jakarta.ee/

5. Jakarta EE 9.1
Overview
• Namespace changed from javax.* to
jakarta.
*
• Compatible with Java 11

6. Eclipse Transformer
• Utilized to mutate class
fi
les at runtime to
automatically rename imports and
references at runtim
e
• Built into Payara 5.x to automatically allow
support for the jakarta.* namespac
e
• Excellent for testin
g
• Best Practice: Fully migrate code prior to
production use

7. Jakarta EE 9.1 -
Compatibility

8. Recipes!
Statement for Completeness:
Recipes are not meant to provide comprehensive coverage
of the features. Rather, they are meant to get you up and
running with the new functionality quickly, providing the
details you need to know. To learn more details on any of
the features covered, please refer to the online
documentation
.

9. About the Example
Three Services using full server pro
fi
le
:
• Client Front En
d
• Event Servic
e
• Database Servic
e
Demonstration via Payara Server, but each can be deployed
to separate containers
.
GitHub: https://github.com/juneau001/EmployeeServices

10. Problem
You’d like to create a Jakarta EE service to
obtain data from an enterprise data store
table and make it available via REST.

11. Solution
Utilize Java Persistence API (JPA) and
Enterprise JavaBeans (EJB) to obtain the
data, and then utilize Jakarta RESTful Web
Services to make the data available for
consumption
.

12. How It Works
• Map Jakarta Persistence entity class to
corresponding database tabl
e
• Utilize a stateless bean to query employee
s
• Make the results available via Jakarta RESTful
Web Service
s

13. Problem
You need to create a front end to consume
the data from the service that was previously
created.

14. Solution
Utilize Jakarta Server Faces to create a front
end, and consume the data using a Jakarta
REST client
.

15. How It Works
• Utilize Jakarta RESTful Web Services client
to query RESTful web service endpoint and
obtain dat
a
• Display data using JSF dataTable and submit/
edit data using reverse technique
.

16. Problem
You’d like to create a form to enter data and
trigger an async CDI event when saved.

17. Solution
Fire the event calling upon the
fi
reAsync()
method, passing the event class
.

18. Solution
Use @ObservesAsync to observe an
asynchronous event
.

19. How it Works
• Utilizes the Java 8 Asynchronous API to
provide a streamlined approach
.
• @ObservesAsync annotation added to
annotate an observer method parameter
so that existing observers annotated with
@Observes would remain synchronous
.
•
fi
reAsync() added to the Event interface.

20. Problem
You would like read in a JSON document and
map it to a Java class or POJO.

21. Solution
U
ti
lize default JSON binding mapping to quickly map
to a POJO.

22. Solution

23. Solution
Create JSON from Java object

24. Solution
Create JSON from Java List

25. How it Works
•JSON-B API provides serializa
ti
on and
deserializa
ti
on opera
ti
ons for
manipula
ti
ng JSON documents to Java
•Default mapping, with custom
annota
ti
on mapping available for
compile-
ti
me
•JsonCon
fi
g class for run
ti
me mapping
customiza
ti
ons

26. Problem
You are interested in
fi
nding a speci
fi
c value
within a JSON document.

27. Solution
U
ti
lize JSON Pointer to
fi
nd the desired value.

28. How it Works
•Create a new JsonPointer object and
pass a string that will be used for
iden
ti
fying a speci
fi
c value.
•

29. How it Works
•Obtain the value by calling the
JsonPointer.getValue() method and
passing the JsonObject you wish to
parse. The JsonValue will contain the
value to which you had pointed.
•

30. Problem
You would like to perform an opera
ti
on on a
a speci
fi
ed value within a JSON document.

31. Solution
U
ti
lize JSON Patch to replace a speci
fi
ed value
within a JSON document with another value.

32. The original document
{"baz": "qux", "foo": "bar"}
The patch
[
{ "op": "replace", "path": "/baz", "value": "boo" },
{ "op": "add", "path": "/hello", "value": ["world"] },
{ "op": "remove", "path": "/foo"}
]
The result
{"baz": "boo","hello": ["world"]}

33. Solution

34. How it Works
•JSON Document or JsonPatchBuilder
•JSON Pointer is used to
fi
nd the value or
sec
ti
on that will be patched
•A series of opera
ti
ons can be applied

35. Problem
You need to fetch and load some data in the
background without locking the scree
n

36. Solution
• Utilize the Jakarta Concurrency API to
initiate a Callable task and spawn it off to
the ManagedExecutorService
.
• On the client, use a polling mechanism to
check the status of the Future object for
completion

37. Learn More