This document compares several Java JSON parsers based on various criteria. It provides an overview of JSON and the Java APIs for processing JSON (JSR 339 and JSR 353). It then evaluates parsers like Jackson, Google GSON, javax.json and others based on criteria like community activity, performance, API features, dependencies and license. The conclusion is that Google GSON is best for small data and Jackson for large data according to previous benchmarks. It asks which parser may be best for RAM-constrained or IoT applications.

1. Java JSON Parser
Comparison
Allan Huang @ Delta DRC

2. Agenda
 JSON
 Java API for RESTful Web Services
 Java API for JSON Processing
 Java EE Compatible Implementations
 JSON Parser
 Evaluation Criterion
 Parser Candidates
 Evaluation Matrix

3. JSON

4. JSON
 JavaScript Object Notation
 A lightweight, text-based, language-independent
data exchange format.
 Built on two structures…
 A collection of name/value pairs, realized as Object:
{ } or Hash Table.
 An ordered list of values, realized as an Array: [ ].
 Used in AJAX applications, configurations,
NoSQL databases, and RESTful web services

5. Java API for RESTful Web
Services
 Defined as JSR 339 in Java EE 7
 JAX-RS 2.0 specification
 Use HTTP methods to interact with the resource
 GET to retrieve a resource
 POST to create a resource
 PUT to update a resource
 DELETE to remove a resource
 Communication between the client and the
endpoint is Stateless.

6. Java API for JSON Processing
 Defined as JSR 353 in Java EE 7
 Streaming API
 JSON Pull Parser
 Similar to StAX API for XML
 Uses an event-based parser that reads JSON data
one element at a time.
 Object Model API
 JSON Push Parser
 Similar to DOM API for XML
 Creates a object tree that represents the JSON data in
memory.

7. Streaming API
 Generates JSON output
to a given stream by
making a function call
with one element at a
time.
 Provides forward, read-
only access to the JSON
data.

8. Streaming API Example
Json Parser Json Generator

9. Object Model API
 Generates JSON output
by navigating the entire
tree at once.
 It’s slower than streaming
model and requires more
memory.

10. Object Model API Example
Json Reader Json Writer

11. Model API Comparison
 If you want to…
 read a large amount
of JSON.
 write JSON to a
char/byte stream.
 random access
JSON in memory.
 reuse JSON without
need to reparse.

12. Java EE 7 Compatible
Implementations
Full Platform distribution Web Profile distribution

13. Java EE 6 Compatible
Implementations (1)
Full Platform distribution

14. Java EE 6 Compatible
Implementations (2)
Web Profile distributions

15. Java EE FAQ
 Web Profile vs. Full Platform
 Java EE introduced the lightweight Web Profile
optimized for web applications.
 e.g. GlassFish Server Open Source Edition 3.1.x
 TomEE
 An all-Apache Java EE Web Profile certified stack
where Apache Tomcat is top dog.
 Current version 1.7 supports Java EE 6
 Next version 2.x support Java EE 7
 Wildfly – formerly known as JBoss AS

16. JSON Parser

17. Evaluation Criterion (1)
 Community Activity
 Repository, Organization, Downloads, Project
References
 Performance Ranking
 Revision
 Previous Release Date, Last Release Date, Last
Revision Number, Revision Frequency, Total
Open Issues

18. Evaluation Criterion (2)
 API Richness
 Object Model API, Streaming API support, Java
Annotation, Serialization / De-serialization,
Documentation & Example
 Dependency
 3rd
-party Libraries
 Minimum JDK Version
 License
 MIT, BSD, Apache 2.0 ...

19. License

20. Parser Candidates
JSON Parser
 json.org
 Jackson
 Google GSON
 json-lib
 javax json
 json-simple
 json-smart
 flexjson
 fastjson
Performance Report
 Top 7 Open-Source JSON-Bin
 JSON serialization
benchmarks
 Revisiting a (JSON) Benchmar
 jvm-serializers
 json-parsers-benchmark
 Json BecnhMark

21. Parser Matrix Java JSON Parser
Criteria javax json Jackson Google GSON json.org json-lib json-simple json-smart flexjson fastjson
Community Activity
Repository Oracle Java Net GitHub Google Code GitHub Sourceforge Google Code Google Code Sourceforge GitHub
Organization Oracle N/A Google JSON org N/A N/A N/A N/A Alibaba
Downloads Unknown Unknown 521,946 Unknown 316,668 228,839 12,213 48,276 8,412
Project References 40 215 forks 8 1268 forks 12 33 7 Unknown 586 forks
Performance
Ranking
Top 7 Open-Source
(Small)
N/A 3 1 N/A 4 N/A N/A 2 N/A
Top 7 Open-Source
(Large)
N/A 1 3 N/A 2 N/A N/A 4 N/A
JSON serialization
benchmarks
N/A 1 2 N/A N/A N/A N/A N/A N/A
Revisiting a (JSON)
Benchmark
N/A 1 2 N/A N/A N/A N/A N/A N/A
jvm-serializers N/A 1 3 6 8 5 4 7 2
json-parsers-
benchmark
(Boon)
N/A 1 2 N/A N/A N/A 3 N/A N/A
Json BecnhMark
(json-smart)
N/A 3 N/A 5 6 4 1 N/A 2
Revision
Previous Release
Date
Unknown 2014/8/15 2013/5/13 Unknown 2009/7/11 2009/2/15 2013/8/13 2013/5/19 2014/5/20
Last Release Date 2013/11/18 2014/10/4 2014/8/11 2014/5/22 2010/12/14 2012/2/18 2013/8/15 2013/7/31 2014/10/11
Last Revision
Number
1.0.4 2.4.3 2.3 N/A 2.4 1.1.1 2.0-RC3 3.2 1.1.42
Revision Frequency Sometimes Always Sometimes Often No Longer No Longer Rarely Rarely Often
Total Open Issues 6 bugs
7 issues
2 pull reqeusts
84 defects
32 enhancements
3 pull requests 35 bugs
10 defects
16 enhancements
5 defects
2 enhancements
8 bugs 10 issues
API Richness
Object Model API
Support
Yes Yes Yes Yes Yes Yes Yes Yes Yes
Streaming API
Support
Yes Yes Yes No No Yes Yes No Yes
Java Annotation Yes Yes Yes No No No No Yes Yes
Serialization & De-
serialization
Yes Yes Yes Yes
Yes, but hard to
use
No
Yes, but hard to
use
Yes Yes
Documentation &
Example
Rich Rich Rich Poor Enough Enough Poor Poor Enough
Dependency
3rd-party Libraries 0 0 0 0 Apache commons 0 0 0 0
Minimum JDK
Version
1.7 1.6 1.6 1.8 1.5 1.2 1.5 1.6 1.5
License License
CDDL 1.1
GPL 2.0
Apache 2.0
LGPL 2.1
Apache 2.0 Apache 2.0 Apache 2.0 Apache 2.0 Apache 2.0 Apache 2.0 Apache 2.0

22. Conclusion
 “Top 7 Open-Source JSON-Binding
Providers Available Today” said…
 Google GSON
 Process small size data
 Jackson
 Process large size data
 Upgrade Java EE 7 application server? Use
Open-Source solution? Which parser is best
for RAM / IoT?

23. Reference
 Java API for JSON Processing: An Introduction to JSON
 Creating JSON Data Using The Java JSON API (JSR 353)
 Java JSON Processing API Example Tutorial
 Top 7 Open-Source JSON-Binding Providers Available Today
 Java EE 7/6 Compatibility
 Java EE FAQ
 GlassFish Server Open Source Edition 3.1.x
 Apache TomEE
 Support JSON JSR 353 - Java API for JSON Processing (JSON-P)
 軟體的授權觀念與自由軟體授權條款介紹

24. Q&A