/**
* Copyright (c) 2005-2012 https://github.com/zhangkaitao
*
* Licensed under the Apache License, Version 2.0 (the "License");
*/
package com.github.zhangkaitao.shiro.chapter22.jcaptcha;
import org.springframework.web.filter.OncePerRequestFilter;
import javax.imageio.ImageIO;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.io.IOException;
/**
* 生成验证码
* <p>User: Zhang Kaitao
* <p>Date: 13-3-22 下午3:36
* <p>Version: 1.0
*/
public class JCaptchaFilter extends OncePerRequestFilter {
@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
response.setDateHeader("Expires", 0L);
response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");
response.addHeader("Cache-Control", "post-check=0, pre-check=0");
response.setHeader("Pragma", "no-cache");
response.setContentType("image/jpeg");
String id = request.getRequestedSessionId();
BufferedImage bi = JCaptcha.captchaService.getImageChallengeForID(id);
ServletOutputStream out = response.getOutputStream();
ImageIO.write(bi, "jpg", out);
try {
out.flush();
} finally {
out.close();
}
}
}