中文算数验证码（加减乘除）

平台被爬虫爬了。故在网上找了有有趣的验证码。为防止向数据库暴力注册入力。原文http://blog.csdn.net/typa01_kk/article/details/45050091

验证码生成工具类：

package com.etoc.customer.web.tool;

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

import org.apache.log4j.Logger;
/**
 * 
 * @ClassName: VerificationCodeTool  
 * @Description: 中文算数验证码 
 * @author ysq
 * @date 2018年2月05日 上午11:18:54 
 *
 */
public class VerificationCodeTool {
    //LOG
    private static final Logger LOG =Logger.getLogger(VerificationCodeTool.class);
    //验证码宽度
    private static final int IMG_WIDTH=146;
    //验证码高度
    private static final int IMG_HEIGHT=30;
    //The number of interference lines
    private static final int DISTURB_LINE_SIZE = 15;
    //generate a random number
    private Random random = new Random();
    //验证码结果
    private int xyresult;
    //验证码
    private String randomString;
    //Chinese Numbers
//    private static final String [] CNUMBERS = "零,一,二,三,四,五,六,七,八,九,十".split(",");
    //零一二三四五六七八九十乘除加减
    //Here, must be java Unicode code
    private static final String CVCNUMBERS = "u96F6u4E00u4E8Cu4E09u56DBu4E94u516Du4E03u516Bu4E5Du5341u4E58u9664u52A0u51CF";
    //字体
    private final Font font = new Font("黑体", Font.BOLD, 18);
    
    private static final Map<String, Integer> OPMap = new HashMap<String, Integer>();
    
    static{
        OPMap.put("*", 11);
        OPMap.put("/", 12);
        OPMap.put("+", 13);
        OPMap.put("-", 14);
    }
    /**
     * The generation of image  verification code
     * */
    public BufferedImage drawVerificationCodeImage(){
        //image
        BufferedImage image = new BufferedImage(IMG_WIDTH, IMG_HEIGHT, BufferedImage.TYPE_INT_RGB);
        //In memory to create a brush
        Graphics g = image.getGraphics();
        g.setColor(Color.WHITE);
        //image background
        g.fillRect(0, 0, IMG_WIDTH, IMG_HEIGHT);
        //Set the brush color
        g.setColor(getRandomColor(200,250));
        //image border
        g.drawRect(0, 0, IMG_WIDTH-2, IMG_HEIGHT-2);
        
        //Set disturb line color
         g.setColor(getRandomColor(110, 133));
         //Generate random interference lines
        for(int i =0;i < DISTURB_LINE_SIZE; i++){
            drawDisturbLine1(g);
            drawDisturbLine2(g);
        }
        //Generate a random number, set return data
        getRandomMathString();
        LOG.info("验证码 : "+randomString);
        LOG.info("验证码结果 : "+xyresult);
        //The generated random string used to save the system
        StringBuffer logsu = new StringBuffer();
        for(int j=0,k = randomString.length(); j < k; j++){
          int chid = 0;
          if(j==1){
              chid = OPMap.get(String.valueOf(randomString.charAt(j)));
          }else{
              chid = Integer.parseInt(String.valueOf(randomString.charAt(j)));
          }
          String ch = String.valueOf(CVCNUMBERS.charAt(chid));
          logsu.append(ch);
          drawRandomString((Graphics2D)g,ch, j);
        }
        //= ?
        drawRandomString((Graphics2D)g,"u7B49u4E8EuFF1F", 3);
        logsu.append("u7B49u4E8E uFF1F");
        LOG.info("汉字验证码 : "+logsu);
        randomString = logsu.toString();
        g.dispose();
        return image;
    }
    /**
     * Get a random string
     * */
    private void getRandomMathString(){
        //Randomly generated number 0 to 10
        int xx = random.nextInt(10);
        int yy = random.nextInt(10);
        //save getRandomString
        StringBuilder suChinese =  new StringBuilder();
            //random 0,1,2
            int Randomoperands = (int) Math.round(Math.random()*2);
            //multiplication
            if(Randomoperands ==0){
                this.xyresult = yy * xx;
//                suChinese.append(CNUMBERS[yy]);
                suChinese.append(yy);
                suChinese.append("*");
                suChinese.append(xx);
            //division, divisor cannot be zero, Be divisible
            }else if(Randomoperands ==1){
                if(!(xx==0) && yy%xx ==0){
                    this.xyresult = yy/xx;
                    suChinese.append(yy);
                    suChinese.append("/");
                    suChinese.append(xx);
                }else{
                    this.xyresult = yy + xx;
                    suChinese.append(yy);
                    suChinese.append("+");
                    suChinese.append(xx);
                }
            //subtraction
            }else if(Randomoperands ==2){
                    this.xyresult = yy - xx;
                    suChinese.append(yy);
                    suChinese.append("-");
                    suChinese.append(xx);
            //add
            }else{
                    this.xyresult = yy + xx;
                    suChinese.append(yy);
                    suChinese.append("+");
                    suChinese.append(xx);
            }
        this.randomString = suChinese.toString();
    }
    /**
     * Draw a random string
     * @param g Graphics
     * @param randomString random string
     * @param i the random number of characters
     * */
    public void drawRandomString(Graphics2D g,String randomvcch,int i){
        //Set the string font style
        g.setFont(font);
        //Set the color string
        int rc = random.nextInt(255);
        int gc = random.nextInt(255);
        int bc = random.nextInt(255);
        g.setColor(new Color(rc, gc, bc));
        //random string
        //Set picture in the picture of the text on the x, y coordinates, random offset value
        int x = random.nextInt(3);
        int y = random.nextInt(2);
        g.translate(x, y);
        //Set the font rotation angle
        int degree = new Random().nextInt() % 15;
        //Positive point of view
        g.rotate(degree * Math.PI / 180, 5+i*25, 20);
        g.drawString(randomvcch, 5+i*25, 20);
        //Reverse Angle
        g.rotate(-degree * Math.PI / 180, 5+i*25, 20);
    }
    /**
     *Draw line interference 
     *@param g Graphics
     * */
    public void drawDisturbLine1(Graphics g){
        int x1 = random.nextInt(IMG_WIDTH);
        int y1 = random.nextInt(IMG_HEIGHT);
        int x2 = random.nextInt(13);
        int y2 = random.nextInt(15);
        g.drawLine(x1, y1, x1 + x2, y1 + y2);
    }
    
    /**
     *Draw line interference 
     *@param g Graphics
     * */
    public void drawDisturbLine2(Graphics g){
        int x1 = random.nextInt(IMG_WIDTH);
        int y1 = random.nextInt(IMG_HEIGHT);
        int x2 = random.nextInt(13);
        int y2 = random.nextInt(15);
        g.drawLine(x1, y1, x1 - x2, y1 - y2);
    }
    /**
     * For random color
     * @param fc fc
     * @param bc bc
     * @return color random color
     * */
    public Color getRandomColor(int fc,int bc){
        if(fc > 255){
            fc = 255;
        }
        if(bc > 255){
            bc = 255;
        }
        //Generate random RGB trichromatic
        int r = fc+random.nextInt(bc -fc - 16);
        int g = fc+random.nextInt(bc - fc - 14);
        int b = fc+random.nextInt(bc - fc - 18);
        return new Color(r, g, b);
    }
    
    /**
     * 返回初始化验证码图片
     * 
     */
    public int getXyresult() {
        return xyresult;
    }
    
    /**
     * randomString.<br/>
     *
     * @return  the randomString <br/>
     * 
     */
    public String getRandomString() {
        return randomString;
    }
    
}

Controller层（没有用servlet）

    @RequestMapping(value = "/getCode", method = {RequestMethod.GET, RequestMethod.POST})
    public @ResponseBody void getCode(HttpServletRequest request, HttpServletResponse response){
      try{
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        //验证码工具
        VerificationCodeTool vcTool = new VerificationCodeTool();
        BufferedImage image = vcTool.drawVerificationCodeImage();
        //验证码结果
        int vcResult = vcTool.getXyresult();
        //验证码
        String vcValue = vcTool.getRandomString();

        response.setHeader("Cache-Control", "no-cache");
        response.setHeader("Pragma", "No-cache");
        response.setDateHeader("Expires", 0);
        response.setContentType("image/jpeg");
        request.getSession().setAttribute("vcResult", vcResult);
        ImageIO.write(image, "JPEG", response.getOutputStream());
//        System.out.println("获取验证码成功 :
验证码:"+vcValue+"
验证码结果:"+vcResult);
    } catch (Exception e) {
//        System.out.println("获取验证码失败");
    }
  }

再说下部署到linux上可能出现的问题（可能服务器上没有验证码上的中文字体）：

　　1：查看CentOS下”/usr/share/fonts“目录，查看新的系统则为空目录；无目录可手动创建fonts。

　　2：打开”C:WindowsFonts“等目录下，找到自己需要的字体的目录，那个文件夹也是见名知意了；

　　3：之后把挑选的字体，可以建个文件夹，一次传到Xftp等上传到服务器的”/usr/share/fonts“的目录下；

　　4：进入"cd /usr/share/fonts"文件夹

　　5：最后在此目录下，执行"#fc-cache -fv"，扫描字体目录并生成字体信息的缓存，然后应用程序就可以"立即"使用这些新安装的字体；

　　6：最终还是要重启web sever，例如：tomcat，字体生效！

　　注：在ubuntu中需要安装：apt-get install fontconfig，侯执行以下命令！     

      附上详情解决方法：Linux环境下"Font font = new Font("黑体", Font.BOLD, 18)"[BufferedImage~Graphics~drawString]中文乱码