Jackson Performance JSON Parser

Question

Several Internet posts point to Jackson as a better syntax performance than GSON, providing somewhere around 20-30% speed improvement.

• http://rick-hightower.blogspot.com/2014/04/new-json-serialization-benchmark.html
• http://tuhrig.de/jaxb-vs-gson-and-jackson/
• http://java.dzone.com/articles/be-lazy-productive-android

Pulling out our GSON parser and replacing it, Jackson led to a slowdown of 7 times in my project with a delay of more than 300 ms per call. The same parsing action on GSON takes less than 50 ms.

I looked at the gotchas list on Wiki Jackson, but nothing stood out like a red flag.

• http://wiki.fasterxml.com/JacksonDataBinding

For example, I do not recreate my ObjectMapper , and I use ObjectReader to read all JSON. Here is a sample code:

 public class JsonParser { @Nonnull private final ObjectMapper objectMapper; public JsonParser() { final ObjectMapper objectMapper = new ObjectMapper(); objectMapper.setDateFormat(DateFormatUtil.getGmtIso8601DateFormat()); SimpleModule simpleModule = new SimpleModule(); objectMapper.registerModule(simpleModule); this.objectMapper = objectMapper; } public <T> T fromJson(InputStream inputStream, Class<T> clazz) throws IOException { ObjectReader reader = objectMapper.reader(clazz); return reader.readValue(inputStream); } } 

The object above is created once and is used throughout the application to translate JSON to POJO. An example of POJO can be seen here:

 @JsonSerialize(include= Inclusion.NON_NULL) @JsonIgnoreProperties(ignoreUnknown = true) public class ActivityEntity { public ActivityObjectEntity actor; public ActivityObjectEntity object; public ActivityObjectEntity provider; public ActivityObjectEntity target; public ActivityObjectEntity generator; public String content; public String title; public String verb; public String url; public Date published; public Date updated; // other properties omitted ... } 

What is serialized is actually a list of the above items.

Here are my examples of trace windows from each run. Notice this is not an anomaly. I sequentially get the same performance order as Gson and Jackson by analyzing the same dataset.

The comparison was with Jackson 2.4.2 and Gson 2.2.4

Answer 1

The code looks right, and even in the worst case, Jackson should be no slower than Gson; and of course nothing is multiple.

If you were able to get a profiler snapshot for the call stack (for continuous deserialization for 10+ seconds), this will probably indicate where the extra time has been spent, and can help figure out the culprit.

I would still double check that JsonParser not created unintentionally several times: one difficult case is, for example, through frameworks such as Jersey (directly or through DropWizard) that can create resources several times, if not to create and use singleton instances, I say this because the symptoms are just right for this case, and not because I doubt that you have performed due diligence.