package y.z.m;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

//产生图片servlet

public class VerifyCodeServlet extends HttpServlet {

    /**
     * 验证码图片的宽度。
     */
    private int width = 120;

    /**
     * 验证码图片的高度。
     */
    private int height = 30;

    /**
     * 验证码字符个数
     */
    private int codeCount = 5;

    /**
     * xx
     */
    private int xx = 0;

    /**
     * 字体高度
     */
    private int fontHeight;

    /**
     * codeY
     */
    private int codeY;

    /**
     * codeSequence
     */
    char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
            'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
            'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
    /**
     * 初始化验证图片属性
     */
    public void init() throws ServletException {
        // 从web.xml中获取初始信息
        // 宽度
        String strWidth = this.getInitParameter("width");
        // 高度
        String strHeight = this.getInitParameter("height");
        // 字符个数
        String strCodeCount = this.getInitParameter("codeCount");

        // 将配置的信息转换成数值
        try {
            if (strWidth != null && strWidth.length() != 0) {
                width = Integer.parseInt(strWidth);
            }
            if (strHeight != null && strHeight.length() != 0) {
                height = Integer.parseInt(strHeight);
            }
            if (strCodeCount != null && strCodeCount.length() != 0) {
                codeCount = Integer.parseInt(strCodeCount);
            }
        } catch (NumberFormatException e) {
            e.printStackTrace();
        }

        xx = width / (codeCount + 1);
        fontHeight = height - 2;
        codeY = height - 4;

    }

    /**
     * @param req
     * @param resp
     * @throws ServletException
     * @throws java.io.IOException
     */
    protected void service(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, java.io.IOException {

        // 定义图像buffer
        BufferedImage buffImg = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_RGB);
        Graphics2D gd = buffImg.createGraphics();

        // 创建一个随机数生成器类
        Random random = new Random();

        // 将图像填充为白色
        gd.setColor(Color.WHITE);
        gd.fillRect(0, 0, width, height);

        // 创建字体，字体的大小应该根据图片的高度来定。
        Font font = new Font("Fixedsys", Font.PLAIN, fontHeight);
        // 设置字体。
        gd.setFont(font);

        // 画边框。
        gd.setColor(Color.BLACK);
        gd.drawRect(0, 0, width - 1, height - 1);

        // 随机产生160条干扰线，使图象中的认证码不易被其它程序探测到。
        gd.setColor(Color.BLACK);
        for (int i = 0; i < 50; i++) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int xl = random.nextInt(12);
            int yl = random.nextInt(12);
            gd.drawLine(x, y, x