FYI,jruby is now 1.5.1, i want to build gpaph service.so i want to familiar with jruby and jfreechart api. this is blow doc is my practice notes.any feedback welcome.
first step:
use jruby+jetty+sinatra stack:
only git clone done.you will have done this stack in local
second step:
create your rb file:
charting.rb
==========
require 'rubygems'
require 'sinatra'
require 'java'
import 'org.jfree.data.category.DefaultCategoryDataset'
class DefaultCategoryDataset
class Inner
def initialize(dataset, row)
@dataset, @row = dataset, row.to_s
end
# a value of nil can call 'removeValue'
def []=(column, value)
@dataset.addValue value.to_java(:int), @row, column.to_s
end
def populate(hash)
hash.each_pair do |column, value|
@dataset.addValue value.to_java(:int), @row, column.to_s
end
end
end
def [](row)
Inner.new self, row
end
end
module Graph
class StackedBar
include_class 'java.io.File'
include_class 'org.jfree.chart.ChartUtilities'
include_class 'org.jfree.chart.JFreeChart'
include_class 'org.jfree.data.category.DefaultCategoryDataset'
include_class 'org.jfree.chart.ChartFactory'
include_class 'org.jfree.chart.plot.PlotOrientation'
def initialize(width=600, height=400, data=[])
@width = width
@height = height
dataset = create_sample_data() if data.empty?
@chart = create_chart(dataset)
end
def render_to_file(filename, format="png")
puts "Rendering graph to #{filename}"
javafile = java.io.File.new(filename)
ChartUtilities.saveChartAsPNG(javafile, @chart, @width, @height)
end
private
def create_sample_data
# This also allows symbols as well as strings
dataset = DefaultCategoryDataset.new
dataset[:Submitted].populate(:A => 1, :B => 2, :C => 3)
dataset[:Assigned].populate(:A => 1, :C => 1)
dataset["In-work"].populate(:A => 3, :C => 3)
dataset[:InVerfication][:A] = 1
dataset[:Delivered][:A] = 2
dataset[:Rejected][:B] = 1
dataset[:Closed][:B] = 1
dataset["On-hold"][:C] = 2
dataset
end
def create_chart(dataset)
chart = ChartFactory.createStackedBarChart("XYZ's Development Projects",
"Project Name",
"Hours",
dataset,
PlotOrientation::VERTICAL,
true,
true,
false)
return chart
end
end # class StackedBar
end # class Graph
get '/' do
sb = Graph::StackedBar.new
@pp = "stacked_bar.png"
img_pub = "public/images/"
sb.render_to_file(img_pub+@pp)
erb :graph
end
