package com.chk.cms.checkcode;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Random;

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

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
import com.sun.xml.internal.ws.api.ha.StickyFeature;

public class CheckCodeServlet extends HttpServlet {

    // 定义验证码 图片的宽度
    private int width;
    // 定义验证码图片的高度。
    private int height;
    // 显示多少位字符
    private int number;
    // 有哪些字符备选
    private String codes;

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("image/jepg");
        // 创建一张图片
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics2D g = image.createGraphics();
        // 设置背景色
        g.setColor(Color.WHITE);
        g.fillRect(0, 0, width, height);
        // 设置黑色边框
        g.setColor(Color.BLACK);
        g.drawRect(0, 0, width - 1, height - 1);
        // 每个字符占据的宽度和高度
        int x = (width - 1) / number;
        int y = height - 4;
        // 定义一个StringBuffer,用于存储code字符串，将来放置到session中
        StringBuffer sb = new StringBuffer();
        // 随机生成字符
        Random random = new Random();
        for (int i = 0; i < number; i++) {
            String code = String.valueOf(codes.charAt(random.nextInt(codes.length())));
            // 随机生成颜色
            int red = random.nextInt(255);
            int green = random.nextInt(255);
            int blue = random.nextInt(255);
            g.setColor(new Color(red, green, blue));
            // 设置字体
            g.setFont(new Font("宋体", Font.BOLD, 14));
            g.drawString(code, i * x + 2, y);
            sb.append(code);
        }
        // 将字符串放置到Http Session中
        request.getSession().setAttribute("codes", sb.toString());

        // 随机生成一些干扰点
        for (int i = 0; i < 50; i++) {
            int red = random.nextInt(255);
            int green = random.nextInt(255);
            int blue = random.nextInt(255);
            g.setColor(new Color(red, green, blue));

            g.drawOval(random.nextInt(width), random.nextInt(height), 1, 1);
        }

        OutputStream out = response.getOutputStream();
        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
        encoder.encode(image);

        out.flush();
        out.close();

    }

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

    public void init() throws ServletException {
        width = Integer.parseInt(this.getInitParameter("width"));
        height = Integer.parseInt(this.getInitParameter("height"));
        number = Integer.parseInt(this.getInitParameter("number"));
        codes = this.getInitParameter("codes");

    }

}

                    

                    
                    
                    
                    

      

        
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