// Version 2 of modified BarChart class from the JFreeChart Example
// Create barchart of currencies and exchange rates from
// data read from two input files.
// These JAR files must be added to the project as dependencies: 
//     jcommon-1.0.23.jar and jfreechart-1.0.19.jar

import java.io.*;
import java.util.Scanner;
import org.jfree.data.category.DefaultCategoryDataset;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.ChartUtilities;
public class BarChart2 {
    public static void main(String[] args) {

        Scanner s1 = null;
        File f1 = new File("currencies.txt");

        try {
            s1 = new Scanner(f1);
        }
        catch (FileNotFoundException e) {
            System.out.println("Couldn't open currencies file.");
            System.out.println(1);
        }

        Scanner s2 = null;
        File f2 = new File("exchange-rates.txt");
        try {
            s2 = new Scanner(f2);
        }
        catch (FileNotFoundException e) {
            System.out.println("Couldn't open input file.");
            System.out.println(1);
        }

        // Create dataset to hold values for barchart.
        DefaultCategoryDataset barChartDataset =
                new DefaultCategoryDataset();

        // Read currency rates from input file using
        // to create bars in barchart
        while(s1.hasNextLine( )) {

            String currency = s1.nextLine( );

            double exchangeRate = Double.parseDouble(s2.nextLine( ));

            // Add data to barchart dataset
            barChartDataset.addValue(exchangeRate,
                    "total", currency);
        }

        // Define JFreeChart object that represents line chart.
        JFreeChart barChartObject = ChartFactory.createBarChart(
                "Currency Exchange Rates",
                "Currency Code",
                "Currency Rate",
                barChartDataset,
                PlotOrientation.VERTICAL,
                false,  // Include legend.
                false,  // Include tooltips.
                false); // Include URLs.

        // Write line chart to a file.
        int imageWidth = 640;
        int imageHeight = 480;
        File barChart = new File("exchange-rates.png");

        try {
            ChartUtilities.saveChartAsPNG(
                    barChart, barChartObject, imageWidth, imageHeight);
        }
        catch (IOException e) {
            System.out.println("Could not output image file.");
            System.exit(2);
        }
    }
}