Java实现中文算数验证码(算数运算+-*/)

原文：http://blog.csdn.net/typa01_kk/article/details/45050091

 /**
     * creat verification code
     * */
    @Action("/getCode")
    public void getCode(){
      //verification code demander
      String vCdemander = request.getParameter("vcdemander");
      try{
        //set encoding
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        //Verification code tool
        VerificationCodeTool vcTool = new VerificationCodeTool();
        BufferedImage image = vcTool.drawVerificationCodeImage();
        //Verification code result
        int vcResult = vcTool.getXyresult();
        String vcValue = vcTool.getRandomString();
        //Set ban cache
        //Cache-control : Specify the request and response following caching mechanism
        //no-cache: Indicates a request or response message cannot cache
        response.setHeader("Cache-Control", "no-cache");
        //Entity header field response expiration date and time are given
        response.setHeader("Pragma", "No-cache");
        response.setDateHeader("Expires", 0);
        // Set the output stream content format as image format
        response.setContentType("image/jpeg");
        //session
        //true: if the session exists, it returns the session, or create a new session.
        //false: if the session exists, it returns the session, otherwise it returns null.
        session=request.getSession(true);
        //set verificationcode to session
        //login
        if("userlogin".equals(vCdemander)){
            session.setAttribute("verificationcodeuserlogin",vcResult);
        }
        //regiser
        if("userregister".equals(vCdemander)){
            session.setAttribute("verificationcodeuserregister",vcResult);
        }
        //To the output stream output image
        ImageIO.write(image, "JPEG", response.getOutputStream());
        System.out.println("获取验证码成功 :\n验证码:"+vcValue+"\n验证码结果:"+vcResult);
        //ResponseUtil.sendImg(response, image, "image/jpeg", "code", "JPEG");
    } catch (Exception e) {
        System.out.println("获取验证码失败");
    }
  }

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;

/**
 *
 */
public class VerificationCodeTool {
    //LOG
    private static final Logger LOG =Logger.getLogger(VerificationCodeTool.class);
    //verification code image width
    private static final int IMG_WIDTH=146;
    //verification code image height
    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();
    //result
    private int xyresult;
    //result random string
    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 = "\u96F6\u4E00\u4E8C\u4E09\u56DB\u4E94\u516D\u4E03\u516B\u4E5D\u5341\u4E58\u9664\u52A0\u51CF";
    //Definition of drawings in the captcha characters font, font name, font style, font size
    //static final font : In Chinese characters garbled
    private final Font font = new Font("黑体", Font.BOLD, 18);
    //data operator
    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();
        //Set the brush color
//        g.setColor(getRandomColor(200,250));
        g.setColor(Color.WHITE);
        //Fill the background color, using the current brush colour changing background color images
        //The meaning of the four parameters respectively, starting x coordinates, starting y, width, height.
        //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,"\u7B49\u4E8E\uFF1F", 3);
        logsu.append("\u7B49\u4E8E \uFF1F");
        LOG.info("汉字验证码 : "+logsu);
        randomString = logsu.toString();
        //Release the brush object
        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);
        //Character spacing is set to 15 px
        //Using the graphics context of the current font and color rendering by the specified string for a given text.
        //The most on the left side of the baseline of the characters in the coordinate system of the graphics context (x, y) location
        //str- to draw string.x - x coordinate.y - y coordinate.
        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);
        //x1 - The first point of the x coordinate.
        //y1 - The first point of the y coordinate
        //x2 - The second point of the x coordinate.
        //y2 - The second point of the y coordinate.
        //X1 and x2 is the starting point coordinates, x2 and y2 is end coordinates.
        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);
        //x1 - The first point of the x coordinate.
        //y1 - The first point of the y coordinate
        //x2 - The second point of the x coordinate.
        //y2 - The second point of the y coordinate.
        //X1 and x2 is the starting point coordinates, x2 and y2 is end coordinates.
        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);
    }

    /**
     * xyresult.<br/>
     *
     * @return  the xyresult <br/>
     *
     */
    public int getXyresult() {
        return xyresult;
    }

    /**
     * randomString.<br/>
     *
     * @return  the randomString <br/>
     *
     */
    public String getRandomString() {
        return randomString;
    }

}