pretty-print-nashorn.cfm

<cfscript>
	function prettyPrintJSON (inputJSON) {
		var engine = createObject("java","javax.script.ScriptEngineManager").init().getEngineByName("nashorn");
    		engine.eval("
			function prettyPrintJSON (data) {
				return JSON.stringify(JSON.parse(data), null, '\t');
			}
		");
		return engine.invokeFunction("prettyPrintJSON", [inputJSON]);
	}
</cfscript>

<cfsavecontent variable="myJSON">
	{"a":1,"b":"foo","c":[true,false,null,"null",{"d":{"e":130000,"f":1.3e5}}]}
</cfsavecontent>

<cfoutput>
	<textarea style="width:100%; height: 100%">#prettyPrintJSON(myJSON)#</textarea>
</cfoutput>

verified working on lucee 4.5

verified now on ACF 11 and 2016

Variable ENGINE is undefined on ColdFusion 10.0.20

10 probably doesnt work because of an older JVM, but thats just a guess.

Good introduction to how you can work back and forth between java and javascript here: http://winterbe.com/posts/2014/04/05/java8-nashorn-tutorial/

and http://www.n-k.de/riding-the-nashorn/