将URL中的JSON文件导入R

Question

I've been trying to import a JSON file into R for a while using both the rjson and RJSONIO package, but I can't get it to work. One of the variations of code I used:

json_file <- "http://toolserver.org/~emw/index.php?c=rawdata&m=get_traffic_data&p1=USA&project1=en&from=12/10/2007&to=4/1/2011"
json_data <- fromJSON(paste(readLines(json_file), collapse=""))

This results in an error message:

Error in fromJSON(paste(readLines(json_file), collapse = "")) : 
unexpected character '<'

I think the problem is in the first line of code, because json_file contains the source of the website, not the actual content. I've tried getURL() and getURLContent(), but without any success. Any help would be much appreciated!

Edit: as pointed out by Martin Morgan, the problem seems to be with the URL, not the code!

Answer 1

library(rjson)
fromJSON(readLines('http://toolserver.org/~emw/index.php?c=rawdata&m=get_traffic_data&p1=USA&project1=en&from=12/10/2007&to=4/1/2011')[1])

works for me, with a warning