What is fastjson Fastjson is a JSON processor (JSON parser + JSON generator) written in Java:

FAST (measured to be faster than any other Java parser and databinder, incudes jackson. ) Powerful (full data binding for common JDK classes as well as any Java Bean class, Collection, Map, Date or enum) Zero-dependency (doest not rely on other packages beyond JDK) Open Source (Apache License 2.0)