Utilizar chamadas REST no Jasper Report Server foi uma bom desafio pra mim, aqui pra vocês o resultiado disso, um pequeno Script que resolve esse "problema" rapidinho. Utilizando BASIC AUTHENTICATION + mais a interface RESTFul do JasperReport.

Look Code in my Github https://github.com/LuizCarvalho/JasperRest/tree/master/ruby

[geshi lang="ruby" nums="1" target="_blank" ]

#!/usr/bin/env ruby
# encoding: utf-8

require "rubygems"
require "net/http"
require "rexml/document"

REPORT_NAME = 'StandardChartsReport'
REPORT_GROUP = "samples"
SERVER_ROOT = "127.0.0.1" #MUDE PARA O ENDERECO DE SEU SERVIDOR
SERVER_PORT = 8080
SERVER_USER = "jasperadmin"
SERVER_PASSWORD = "jasperadmin"
FORMAT = "PDF"
FILE_NAME = "report.pdf"

REPORT_PATH = "http://#{SERVER_ROOT}:#{SERVER_PORT}/jasperserver/rest/report"

def to_ms(time)
	start = Time.new(1970,1,1)
	((time.to_f - start.to_f) * 1000.0).to_i
end

#parametros sendo passados somente como exemplo
PARAMS = {:criacao_inicio=>to_ms(Time.new(2011,01,01)),:criacao_final=>to_ms(Time.new(2014,01,01))}

def build_xml_request
	url_string = "/reports/#{REPORT_GROUP}/#{REPORT_NAME}"
	request_body = "null"
	puts "CRIANDO XML PARA: #{url_string} "
	PARAMS.each do|k,v|
		request_body += "#{v.to_s}"
		puts "PARAMETROS: #{k}=#{v.to_s}; "
	end
	request_body += ""
end

def get_uuid_and_cookie

	body = ""
	cookie = ""
	puts "FULL URL: #{"#{REPORT_PATH}/reports/#{REPORT_GROUP}/#{REPORT_NAME}"}"
	uri = URI.parse("#{REPORT_PATH}/reports/#{REPORT_GROUP}/#{REPORT_NAME}")
	http = Net::HTTP.new(uri.host, uri.port)
	http.start do |http|
		req = Net::HTTP::Put.new(uri.path + "?RUN_OUTPUT_FORMAT=#{FORMAT}")
		puts "ACESSANDO: #{uri.path}?RUN_OUTPUT_FORMAT=#{FORMAT}"
		req.basic_auth(SERVER_USER, SERVER_PASSWORD)
		req.body = build_xml_request
		resp = http.request(req)
		body = resp.body
		puts "COOKIE RECEBIDO: #{resp['Set-Cookie']}"
		cookie = resp['Set-Cookie']
	end

	xml = REXML::Document.new(body)
	puts "\n\n XML \n #{xml} \n\n"
	uuid_xml = xml.elements["report/uuid"]

	if uuid_xml
		uuid = uuid_xml.text
		puts "UUID RECEBIDO: #{uuid}"
		return uuid,cookie
	else
		puts "PROBLEMA AO RECEBER UUID. RESPOSTA: #{uuid_xml}"
		return false,false
	end
end

def get_file
	body_get = nil
	uuid,cookie = get_uuid_and_cookie
	if uuid
		uri_get = URI.parse("#{REPORT_PATH}/#{uuid}")
		puts "URL DO RELATORIO: #{uri_get}"
		http_get = Net::HTTP.new(uri_get.host, uri_get.port)

		http_get.start do |http|
			req = Net::HTTP::Get.new(uri_get.path + "?file=report")
			puts "REQ: #{req.path}"
			req.basic_auth(SERVER_USER, SERVER_PASSWORD)
			req['cookie'] = cookie
			resp = http.request(req)
			body_get = resp.body
		end
	end
	body_get
end

file = get_file
if file
	#puts file
	f = File.new(FILE_NAME, 'wb')
	f.write(file)
	f.close
else
	puts "Não foi possível criar o relatório"
end

[/geshi]

[github file = "{https://github.com/LuizCarvalho/JasperRest/blob/master/ruby/report_rest.rb}"]