[hardwired]

Code:

import java.awt.*;
import java.awt.geom.*;
import java.util.*;
import javax.swing.*;

public class H2 extends JPanel {
    int[] data;
    final int PAD = 20;
    final int BAR_HEIGHT = 25;

    H2(int[] data) {
        this.data = data;
        System.out.print(Arrays.toString(data));
    }

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        int w = getWidth();
        int h = getHeight();
        // draw axes
        g2.draw(new Line2D.Double(PAD, PAD, PAD, h-PAD));
        g2.draw(new Line2D.Double(PAD, h-PAD, w-PAD, h-PAD));
        int numBars = data.length;
        double yInc = (double)(h - 2*PAD - numBars*BAR_HEIGHT)/(numBars-1);
        int maxValue = getMaxValue();
        double unitLength = (double)(w - 2*PAD)/maxValue;
        // plot data
        g2.setPaint(Color.blue);
        for(int j = 0; j < numBars; j++) {
            double y = PAD + j * (BAR_HEIGHT + yInc);
            double width = unitLength*data[j];
            g2.fill(new Rectangle2D.Double(PAD, y, width, BAR_HEIGHT));
        }
    }

    private int getMaxValue() {
        int max = -Integer.MAX_VALUE;
        for(int j = 0; j < data.length; j++) {
            if(data[j] > max)
                max = data[j];
        }
        return max;
    }

    public static void main(String[] args) {
        Random seed = new Random();
        int[] vals = new int[10];
        for(int j = 0; j < vals.length; j++) {
            vals[j] = seed.nextInt(100);
            System.out.print(vals[j]);
            if(j < vals.length-1) System.out.print(" ");
            else                  System.out.println();
        }
        HistogramFreq freqCalc = new HistogramFreq(vals);
        int[] freqs = freqCalc.getValues();
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(new H2(freqs));
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
    }
}

class HistogramFreq {
    int[] frequency;
    int range = 10;

    public HistogramFreq(int[] inputtedValue) {
        determineFrequency(inputtedValue);  
    }

    public int[] getValues() {
        return frequency;
    }

    public void determineFrequency(int[] valuesProvided) {
        // stores frequency of inputted numbers in the appropriate ranges
        frequency = new int[range];
        // for each range increment the appropriate range 
        for( int valueEntered : valuesProvided)
            ++frequency[valueEntered/range];
    }
}