cn.apiclub.captcha.servlet.SimpleCaptchaServlet Maven / Gradle / Ivy

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package cn.apiclub.captcha.servlet;

import static cn.apiclub.captcha.Captcha.NAME;

import java.awt.Color;
import java.awt.Font;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import cn.apiclub.captcha.Captcha;
import cn.apiclub.captcha.backgrounds.GradiatedBackgroundProducer;
import cn.apiclub.captcha.text.renderer.ColoredEdgesWordRenderer;


/**
 * Generates, displays, and stores in session a 200x50 CAPTCHA image with sheared 
 * black text, a solid dark grey background, and a slightly curved line over the 
 * text.
 * 
 * @author James Childers
 */
public class SimpleCaptchaServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    private static int _width = 200;
    private static int _height = 50;
    
    private static final List COLORS = new ArrayList(2);
    private static final List FONTS = new ArrayList(3);
    
    static {
        COLORS.add(Color.BLACK);
        COLORS.add(Color.BLUE);

        FONTS.add(new Font("Geneva", Font.ITALIC, 48));
        FONTS.add(new Font("Courier", Font.BOLD, 48));
        FONTS.add(new Font("Arial", Font.BOLD, 48));
    }

    @Override
    public void init(ServletConfig config) throws ServletException {
        super.init(config);
    	if (getInitParameter("captcha-height") != null) {
    		_height = Integer.valueOf(getInitParameter("captcha-height"));
    	}
    	
    	if (getInitParameter("captcha-width") != null) {
    		_width = Integer.valueOf(getInitParameter("captcha-width"));
    	}
    }
    
    @Override
    public void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        ColoredEdgesWordRenderer wordRenderer = new ColoredEdgesWordRenderer(COLORS, FONTS);
        Captcha captcha = new Captcha.Builder(_width, _height).addText(wordRenderer)
                .gimp()
                .addNoise()
                .addBackground(new GradiatedBackgroundProducer())
                .build();

        CaptchaServletUtil.writeImage(resp, captcha.getImage());
        req.getSession().setAttribute(NAME, captcha);
    }
}