Axeda Groovy Script: Get Precipitation by a given latitude and Longitude

[#1]

This Groovy script gets the weather forecast for a given lat/long by calling an external web service.

Use in an Expression rule like this:

If: something

Then: SetDataItem ("precipitation", round(ExecuteCustomObject ("GetPrecipitation", location) ))

This sets the dataitem "precipitation" to the value returned by this script.

Parameters:

Variable Name               Display Name
location                         localtion (lat, lon)

import org.apache.commons.httpclient.methods.*
import org.apache.commons.httpclient.*
import java.text.SimpleDateFormat
def location = parameters.location.toString()
def locparts = location.split(',')
def lat = locparts[0]
def lon = locparts[1]
def hostname = " www.weather.gov"
def url = "/forecasts/xml/sample_products/browser_interface/ndfdXMLclient.php"
String ndfdElement = "pop12" // see http://www.weather.gov/forecasts/xml/docs/elementInputNames.php
def perceptTimeFormat = new SimpleDateFormat ("yyyy-MM-dd'T'HH:mm:ss");
def cal = Calendar.getInstance();
Date startDate = cal.getTime()
cal.add(Calendar.HOUR,12)
Date endDate = cal.getTime()
def client = new HttpClient ()
HostConfiguration host = client.getHostConfiguration()
host.setHost(hostname, 80, "http")
GetMethod get = new GetMethod (url)
NameValuePair [] params = new NameValuePair [6]
params[0] = new NameValuePair ("lat", lat);
params[1] = new NameValuePair ("lon", lon);
params[2] = new NameValuePair ("product", 'time-series');
params[3] = new NameValuePair ("begin", perceptTimeFormat.format(startDate));
params[4] = new NameValuePair ("end", perceptTimeFormat.format(endDate));
params[5] = new NameValuePair (ndfdElement, ndfdElement);
get.setQueryString(params)
client.executeMethod(host, get);
message = "Status:" + get.getStatusText()
content = get.getResponseBodyAsString()
get.releaseConnection()
// parse result XML and compute average
def dwml = new XmlSlurper ().parseText(content)
readings = dwml.data.parameters."probability-of-precipitation".value.collect { Integer.parseInt(it.toString()) }
average = readings.sum() / readings.size()
//logger.info "Expected precipitation for $location is $readings"
return readings[0]