Captcha.java

import java.awt.Color;
import java.awt.Font;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import javax.imageio.ImageIO;

import jj.play.ns.nl.captcha.backgrounds.BackgroundProducer;
import jj.play.ns.nl.captcha.backgrounds.FlatColorBackgroundProducer;
import jj.play.ns.nl.captcha.backgrounds.GradiatedBackgroundProducer;
import jj.play.ns.nl.captcha.backgrounds.SquigglesBackgroundProducer;
import jj.play.ns.nl.captcha.backgrounds.TransparentBackgroundProducer;
import jj.play.ns.nl.captcha.gimpy.GimpyRenderer;
import jj.play.ns.nl.captcha.gimpy.RippleGimpyRenderer;
import jj.play.ns.nl.captcha.noise.CurvedLineNoiseProducer;
import jj.play.ns.nl.captcha.text.renderer.DefaultWordRenderer;
import play.exceptions.UnexpectedException;

public class Captcha extends InputStream {

    public String text = null;
    public BackgroundProducer background = new TransparentBackgroundProducer();
    public GimpyRenderer gimpy = new RippleGimpyRenderer();
    public Color textColor = Color.BLACK;
    public List<Font> fonts = new ArrayList<Font>(2);
    public int w, h;
    public Color noise = null;

    public Captcha(int w, int h) {
        this.w = w;
        this.h = h;
        this.fonts.add(new Font("Arial", Font.BOLD, 40));
        this.fonts.add(new Font("Courier", Font.BOLD, 40));
    }

    /**
     * Tell the captche to draw a text and retrieve it
     */
    public String getText() {
        return getText(5);
    }

    /**
     * Tell the captche to draw a text using the specified color (ex. #000000) and retrieve it
     */
    public String getText(String color) {
        this.textColor = Color.decode(color);
        return getText();
    }

    /**
     * Tell the captche to draw a text of the specified size and retrieve it
     */
    public String getText(int length) {
        return getText(length, "abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ23456789");
    }

    /**
     * Tell the captche to draw a text of the specified size using the specified color (ex. #000000) and retrieve it
     */
    public String getText(String color, int length) {
        this.textColor = Color.decode(color);
        return getText(length);
    }

    public String getText(int length, String chars) {
        char[] charsArray = chars.toCharArray();
        Random random = new Random(System.currentTimeMillis());
        StringBuffer sb = new StringBuffer(length);
        for (int i = 0; i < length; i++) {
            sb.append(charsArray[random.nextInt(charsArray.length)]);
        }
        text = sb.toString();
        return text;
    }

    public String getText(String color, int length, String chars) {
        this.textColor = Color.decode(color);
        return getText(length, chars);
    }

    /**
     * Add noise to the captcha.
     */
    public Captcha addNoise() {
        noise = Color.BLACK;
        return this;
    }

    /**
     * Add noise to the captcha.
     */
    public Captcha addNoise(String color) {
        noise = Color.decode(color);
        return this;
    }

    /**
     * Set a gradient background.
     */
    public Captcha setBackground(String from, String to) {
        GradiatedBackgroundProducer bg = new GradiatedBackgroundProducer();
        bg.setFromColor(Color.decode(from));
        bg.setToColor(Color.decode(to));
        background = bg;
        return this;
    }

    /**
     * Set a solid background.
     */
    public Captcha setBackground(String color) {
        background = new FlatColorBackgroundProducer(Color.decode(color));
        return this;
    }

    /**
     * Set a squiggles background
     */
    public Captcha setSquigglesBackground() {
        background = new SquigglesBackgroundProducer();
        return this;
    }        // ~~ rendering
    ByteArrayInputStream bais = null;

    @Override
    public int read() throws IOException {
        check();
        return bais.read();
    }

    @Override
    public int read(byte[] b) throws IOException {
        check();
        return bais.read(b);
    }

    void check() {
        try {
            if (bais == null) {
                if (text == null) {
                    text = getText();
                }
                BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
                DefaultWordRenderer renderer = new DefaultWordRenderer(textColor, fonts);
                bi = background.addBackground(bi);
                renderer.render(text, bi);
                if (noise != null) {
                    new CurvedLineNoiseProducer(noise, 3.0f).makeNoise(bi);
                }
                gimpy.gimp(bi);
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                ImageIO.write(bi, "png", baos);
                bais = new ByteArrayInputStream(baos.toByteArray());
                
                //easezhang  delete this line from play for play context depending
                //Response.current().contentType = "image/png";
            }
        } catch (Exception e) {
            throw new UnexpectedException(e);
        }
    }
}