Comparing JSON Lib

1. Comparing
JSON libraries
Sean Sullivan
Portland Java User Group
July 19, 2011

6. JavaScript Object Notation

7. {
“hello” : “world”,
“count” : 1
}
pentagon hexagon json

8. JSON is a data interchange format

9. {
“name” : “Mock Crest Tavern”,
“tags” : [ “music”, “beer”, “tots” ],
“location” :
{
“city” : “Portland”,
“state” : “Oregon”
}
}

10. JSON
• based on a subset of the JavaScript
programming language
• text format
• language independent

11. RFC 4627

12. How is JSON useful to Java developers?

14. Web Services

18. “In the first version of our API, data was available
in XML, with JSON support added largely as an
afterthought. XML as a means for delivering
developer-friendly data hasn’t aged well. Seeing
the growing inclination of developers and API
makers alike towards JSON, we’ve decided to
eliminate XML support and put the energy spent
there into getting our JSON implementation just
right.”
July 2011
http://engineering.tumblr.com/post/7541361718/introducing-tumblrs-new-api

20. JSON libraries
• json.org library
• Google GSON
• Jackson
• lift-json

21. http://json.org/javadoc

22. import org.json.*;
JSONObject obj = new JSONObject();
obj.put(“Hello”, “World”);
obj.put(“count”, 1);
String json = obj.toString();

23. http://jackson.codehaus.org/

24. import org.codehaus.jackson.*;
import org.codehaus.jackson.map.*;
ObjectMapper mapper = new ObjectMapper();
String json = mapper.writeValueAsString(foo);
Foo foo2 = mapper.readValue(json, Foo.class);

27. http://code.google.com/p/google-gson/

28. import com.google.gson.*;
GsonBuilder builder = new GsonBuilder();
Gson gson = builder.create();
String json = gson.toJson(foo);
Foo foo2 = gson.fromJson(json, Foo.class);

29. Jackson vs GSON
• GSON serializes all non-transient non-
static fields. GSON accesses fields directly
with Java’s Reflection API
• Jackson uses JavaBean methods (setter
methods / getter methods)

30. JSON and Scala

31. lift-json

32. JSON and Android

35. JsonReader,
json.org
JsonWriter
Android 1.x Y N
Android 2.x Y N
Android 3.x Y Y

36. Benchmarks

39. Related topics

41. Native JSON
http://blogs.msdn.com/ie/archive/2008/09/10/native-json-in-ie8.aspx
http://blog.mozilla.com/webdev/2009/02/12/native-json-in-firefox-31/

42. For more information
• http://www.json.org
• http://en.wikipedia.org/wiki/JSON

43. Thank you