aka ObjectReader/ObjectWriter, JsonMapper.builder FTW

The most often used class in the whole Jackson databind API is — without question — ObjectMapper. ObjectMapper has been around since Jackson 0.9.5 and has methods for reading and writing JSON (*), for converting structurally compatible values, and for configuring details of these operations.
Because of this, it is widely…

“How to use jackson-dataformat-csv, part 2”

Now that we know how to read CSV with Jackson…

Ok, so the assumption is that you have read my earlier post (Reading CSV with Jackson) — if not, it would probably make sense to do that first as I will be expanding on some of the aspects without repeating explanations.

But here’s a brief recap:

  • While Jackson started as…

aka “Why is UUID.fromString() so slow?”

Similar to my recent adventure into evaluating performance of String.format() for simple String concatenation, I found another potentially meaningful case of widely used (and useful) JDK-provided functionality that seems to significantly under-perform: decoding of java.util.UUID from a String:

UUID uuid = UUID.fromString(request.getParameter("uuid"));

This was found to be a hot spot…


Open Source developer, most known for Jackson data processor (nee “JSON library”), author of many, many other OSS libraries for Java, from ClassMate to Woodstox

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