Having been tasked to generate some JSON in Java, I went out looking for tools, because I hate dealing with the trivia of punctuation. :)
I found the JsonWriter which generated correctly formed JSON.
Slowly. Very slowly. As in, it took about seven seconds to format 18,000 cells of data based on my rough count as it ran in the JDev debugger.
Not surprisingly, folks were not exactly thrilled with that report.
So I did some more research today. It turns out that JsonWriter constructs a JSON structure in memory, much like DOM does for XML. If you've got an itty-bitty structure, this is just fine. If you have large structures, not so much.
Happily, there is a streaming JSON API via the JsonGenerator interface. It plunked out the same 750K of data in less than a second. The limiting factor no longer appears to be the speed with which I can generate the JSON, but rather the speed with which I can retrieve the data and convert it from numeric to string format.