验证码相关

package com.springmvc.Common;import javax.imageio.ImageIO;import java.awt.*;import java.awt.image.BufferedImage;import java.io.IOException;import java.io.OutputStream;import java.util.Random;/** * Created by lenovo on 2017/9/10. */public class Validation {    public static final char[] CHARS = {'1','2','3','4','5','6','7','8','9','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'};    Random random = new Random();    public String getRandomString(){        StringBuffer stringBuffer = new StringBuffer();        for (int i = 1;i < 4;i++){            stringBuffer.append(CHARS[random.nextInt(CHARS.length)]);        }        return stringBuffer.toString();    }    public Color getRandomColor(){        return new Color(random.nextInt(255),random.nextInt(255),random.nextInt(255));    }    public Color getReverseColor(Color color){        return new Color(255 - color.getRed(),255 - color.getGreen(),255 - color.getBlue());    }    String text = getRandomString();    public String getText(){        return text;    }    public BufferedImage getBufferedImage(int width,int height){        Color color = getRandomColor();        Color reverse = getReverseColor(color);        BufferedImage bufferedImage = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);        Graphics2D graphics2D = bufferedImage.createGraphics();        graphics2D.setFont(new Font(Font.SANS_SERIF,Font.BOLD,20));        graphics2D.setColor(color);        graphics2D.fillRect(0,0,width,height);        graphics2D.setColor(reverse);        graphics2D.drawString(text,10,22);        for (int i = 0,n = random.nextInt(80);i < n;i++){            graphics2D.drawRect(random.nextInt(width),random.nextInt(height),1,1);        }        return bufferedImage;    }    public void output(BufferedImage bufferedImage, OutputStream outputStream) throws IOException {        ImageIO.write(bufferedImage,"JPEG",outputStream);    }}

@RequestMapping("/validation")    public void validate(HttpServletResponse response) throws IOException {        Validation validation = new Validation();        BufferedImage bufferedImage = validation.getBufferedImage(100,30);//设置验证图片的大小        HttpSession session = getSession();        session.setAttribute("sessionValidation",validation.getText());        validation.output(bufferedImage,response.getOutputStream());    }