in src/main/java/org/apache/sling/commons/metrics/internal/JSONReporter.java [281:292]
private static Object jsonSafeValue(Object v){
//Json does not allow NaN or infinite doubles. So take care of that
if (v instanceof Number){
if (v instanceof Double){
Double d = (Double) v;
if (d.isInfinite() || d.isNaN()){
return d.toString();
}
}
}
return v;
}