@RequestMapping("/getSecurityCode") //对应/user/valicode.do请求
@ResponseBody
public UserResult valicode(HttpServletResponse response,HttpSession session){
//利用图片工具生成图片
  try {
    //第一个参数是生成的验证码，第二个参数是生成的图片Object[] objs = ImageUtil.createImage();//将验证码存入Sessionsession.setAttribute("imageCode",objs[0]);
　　 //将图片输出给浏览器log.info("------图片session----"+objs[0]);BufferedImage image = (BufferedImage) objs[1];response.setContentType("image/png");OutputStream os = response.getOutputStream();ImageIO.write(image, "png", os);return UserResult.ok(null, "ok");} catch (Exception e) {e.printStackTrace();log.info(e.fillInStackTrace());return UserResult.error(ToolString.exception, "验证码生成异常！");}
}

package com.soshare.util;import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;import javax.imageio.ImageIO;public class ImageUtil {// 验证码字符集private static final char[] chars = { '0', '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','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'};// 字符数量private static final int SIZE = 4;// 干扰线数量private static final int LINES = 5;// 宽度private static final int WIDTH = 80;// 高度private static final int HEIGHT = 40;// 字体大小private static final int FONT_SIZE = 30;/*** 生成随机验证码及图片* Object[0]：验证码字符串；* Object[1]：验证码图片。*/public static Object[] createImage() {StringBuffer sb = new StringBuffer();// 1.创建空白图片BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);// 2.获取图片画笔Graphics graphic = image.getGraphics();// 3.设置画笔颜色
        graphic.setColor(Color.LIGHT_GRAY);// 4.绘制矩形背景graphic.fillRect(0, 0, WIDTH, HEIGHT);// 5.画随机字符Random ran = new Random();for (int i = 0; i <SIZE; i++) {// 取随机字符索引int n = ran.nextInt(chars.length);// 设置随机颜色
            graphic.setColor(getRandomColor());// 设置字体大小graphic.setFont(new Font(null, Font.BOLD + Font.ITALIC, FONT_SIZE));// 画字符
            graphic.drawString(chars[n] + "", i * WIDTH / SIZE, HEIGHT*2/3);// 记录字符
            sb.append(chars[n]);}// 6.画干扰线for (int i = 0; i < LINES; i++) {// 设置随机颜色
            graphic.setColor(getRandomColor());// 随机画线
            graphic.drawLine(ran.nextInt(WIDTH), ran.nextInt(HEIGHT),ran.nextInt(WIDTH), ran.nextInt(HEIGHT));}// 7.返回验证码和图片return new Object[]{sb.toString(), image};}/*** 随机取色*/public static Color getRandomColor() {Random ran = new Random();Color color = new Color(ran.nextInt(256), ran.nextInt(256), ran.nextInt(256));return color;}//验证码是否正确public static boolean validate(String code,String session) {if(!Tool.isNotNull(code)||!Tool.isNotNull(session)) {return false;}code = code.toUpperCase();session = session.toUpperCase();return code.equals(session);}public static void main(String[] args) throws IOException {Object[] objs = createImage();BufferedImage image = (BufferedImage) objs[1];OutputStream os = new FileOutputStream("d:/1.png");ImageIO.write(image, "png", os);os.close();}}