BarcodeGenerator

BarcodeGenerator.java

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.awt.image.RenderedImage;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;

public class BarcodeGenerator {
    public static void main(String[] args) throws IOException {
        BarcodeGenerator barcodeGenerator = new BarcodeGenerator(2, 100);
        RenderedImage barcodeImage = barcodeGenerator.generateBarcodeImage("123456789");

        File file = new File("barcode.png");
        ImageIO.write(barcodeImage, "png", file);
    }

    private static final int DEFAULT_BARCODE_LINE_WIDTH = 5;
    private static final int DEFAULT_BARCODE_LINE_HEIGHT = 100;

    private final int barcodeLineWidth;
    private final int barcodeLineHeight;

    public BarcodeGenerator() {
        this.barcodeLineWidth = DEFAULT_BARCODE_LINE_WIDTH;
        this.barcodeLineHeight = DEFAULT_BARCODE_LINE_HEIGHT;
    }

    public BarcodeGenerator(int barcodeLineWidth, int barcodeLineHeight) {
        this.barcodeLineWidth = barcodeLineWidth;
        this.barcodeLineHeight = barcodeLineHeight;
    }

    public RenderedImage generateBarcodeImage(String message) {
        Code39 code39 = new Code39(message);
        int[] barcode = code39.barcode();
        int width = barcodeLineWidth * barcode.length;
        int height = barcodeLineHeight;

        BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        Graphics2D g2d = bufferedImage.createGraphics();
        for (int i = 0; i < barcode.length; i++) {
            if (barcode[i] == 0) {
                g2d.setColor(Color.WHITE);
            } else {
                g2d.setColor(Color.BLACK);
            }
            g2d.fillRect(i * barcodeLineWidth, 0, barcodeLineWidth, height);
        }

        g2d.dispose();
        return bufferedImage;
    }

    public static class Code39 {
        private static final int INTEGERS_PER_SYMBOL = 12;
        private String code;
        private int[] bars;

        public Code39(String code) {
            this.code = code.toUpperCase().trim();

            bars = new int[(code.length() + 2) * INTEGERS_PER_SYMBOL];

            this.buildSequence();
        }

        public void buildSequence() {
            String encoded = "*" + code + "*";

            int p = 0;
            for (int i = 0; i < encoded.length(); i++) {
                int[] sequence = mapSequence(encoded.charAt(i), i);
                System.arraycopy(sequence, 0, bars, p, sequence.length);
                p += sequence.length;
            }
        }

        public int[] mapSequence(char c, int pos) {
            HashMap<Character, int[]> sequence = new HashMap<Character, int[]>();

            sequence.put('0', new int[]{1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1});
            sequence.put('1', new int[]{1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1});
            sequence.put('2', new int[]{1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1});
            sequence.put('3', new int[]{1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1});
            sequence.put('4', new int[]{1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 1});
            sequence.put('5', new int[]{1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1});
            sequence.put('6', new int[]{1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1});
            sequence.put('7', new int[]{1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1});
            sequence.put('8', new int[]{1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1});
            sequence.put('9', new int[]{1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1});
            sequence.put('A', new int[]{1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1});
            sequence.put('B', new int[]{1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1});
            sequence.put('C', new int[]{1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1});
            sequence.put('D', new int[]{1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1});
            sequence.put('E', new int[]{1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1});
            sequence.put('F', new int[]{1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1});
            sequence.put('G', new int[]{1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1});
            sequence.put('H', new int[]{1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1});
            sequence.put('I', new int[]{1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1});
            sequence.put('J', new int[]{1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1});
            sequence.put('K', new int[]{1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1});
            sequence.put('L', new int[]{1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1});
            sequence.put('M', new int[]{1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1});
            sequence.put('N', new int[]{1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1});
            sequence.put('O', new int[]{1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1});
            sequence.put('P', new int[]{1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1});
            sequence.put('Q', new int[]{1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1});
            sequence.put('R', new int[]{1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1});
            sequence.put('S', new int[]{1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1});
            sequence.put('T', new int[]{1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1});
            sequence.put('U', new int[]{1, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1});
            sequence.put('V', new int[]{1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1});
            sequence.put('W', new int[]{1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1});
            sequence.put('X', new int[]{1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1});
            sequence.put('Y', new int[]{1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1});
            sequence.put('Z', new int[]{1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1});
            sequence.put('-', new int[]{1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1});
            sequence.put('.', new int[]{1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1});
            sequence.put(' ', new int[]{1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1});
            sequence.put('$', new int[]{1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1});
            sequence.put('/', new int[]{1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1});
            sequence.put('+', new int[]{1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1});
            sequence.put('%', new int[]{1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1});
            sequence.put('*', new int[]{1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1});

            return sequence.get(c);
        }

        public int[] barcode() {
            return bars;
        }

        public String code() {
            return code;
        }

        public int calculateCheckDigit() {
            return 0;
        }
    }
}