java數字和中文算數驗證碼的實現

阿新 • • 發佈：2020-07-13

本文介紹了java數字和中文算數驗證碼的實現，分享給大家，具體如下：

效果圖

java數字和中文算數驗證碼的實現

本文程式碼 https://gitee.com/tothis/java-record/tree/master/src/main/java/com/example/captcha

中文實現參考 https://gitee.com/whvse/EasyCaptcha.git

數字實現參考 https://www.jb51.net/article/190561.htm

程式碼如下

中文演算法

package com.example.captcha;

import lombok.extern.slf4j.Slf4j;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;

/**
 * @author 李磊
 * @datetime 2020/7/9 20:10
 * @description
 */
@Slf4j
public class ChineseCaptcha {
 // 寬度
 private static final int IMAGE_WIDTH = 160;
 // 高度
 private static final int IMAGE_HEIGHT = 40;
 // 字型大小
 private static final int FONT_SIZE = 28;
 // 干擾線數量
 private static final int IMAGE_DISTURB_LINE_NUMBER = 15;
 // 字尾
 private static final String SUFFIX = "等於？";

 // 漢字數字
 private static final String SOURCE = "零一二三四五六七八九十乘除加減";

 // 計算型別
 private static final Map<String,Integer> calcType = new HashMap<>();
 private static final Random RANDOM = new Random();

 static {
  // 對應SOURCE下標
  calcType.put("*",11);
  calcType.put("/",12);
  calcType.put("+",13);
  calcType.put("-",14);
 }

 // 計算公式
 private String content;
 // 計算結果
 private int result;

 /**
  * 生成影象驗證碼
  */
 public BufferedImage create() {
  createMathChar();
  BufferedImage image = new BufferedImage(IMAGE_WIDTH,IMAGE_HEIGHT,BufferedImage.TYPE_INT_RGB);
  Graphics g = image.getGraphics();
  // 字型顏色
  g.setColor(Color.WHITE);
  // 背景顏色
  g.fillRect(0,IMAGE_WIDTH,IMAGE_HEIGHT);
  g.setColor(color());
  // 圖片邊框
  g.drawRect(0,IMAGE_WIDTH - 1,IMAGE_HEIGHT - 1);
  g.setColor(color());
  for (int i = 0; i < IMAGE_DISTURB_LINE_NUMBER; i++) {
   // 繪製干擾線
   int x1 = RANDOM.nextInt(IMAGE_WIDTH);
   int y1 = RANDOM.nextInt(IMAGE_HEIGHT);
   int x2 = RANDOM.nextInt(13);
   int y2 = RANDOM.nextInt(15);
   g.drawLine(x1,y1,x1 + x2,y1 + y2);
  }
  StringBuilder builder = new StringBuilder();
  for (int i = 0,j = content.length(); i < j; i++) {
   int index;
   if (i == 1) {
    index = calcType.get(String.valueOf(content.charAt(i)));
   } else {
    index = Integer.parseInt(String.valueOf(content.charAt(i)));
   }
   String ch = String.valueOf(SOURCE.charAt(index));
   builder.append(ch);
   drawString((Graphics2D) g,ch,i);
  }
  drawString((Graphics2D) g,SUFFIX,3);
  content = builder.append(SUFFIX).toString();
  g.dispose();
  return image;
 }

 private void createMathChar() {
  StringBuilder number = new StringBuilder();
  // 10以內數字
  int xx = RANDOM.nextInt(10);
  int yy = RANDOM.nextInt(10);
  // 0~3 對應加減乘除
  int round = (int) Math.round(Math.random() * 3);
  if (round == 0) {
   this.result = yy + xx;
   number.append(yy);
   number.append("+");
   number.append(xx);
  } else if (round == 1) {
   this.result = yy - xx;
   number.append(yy);
   number.append("-");
   number.append(xx);
  } else if (round == 2) {
   this.result = yy * xx;
   number.append(yy);
   number.append("*");
   number.append(xx);
  } else {
   // 0不可為被除數 yy對xx取餘無餘數
   if (!(xx == 0) && yy % xx == 0) {
    this.result = yy / xx;
    number.append(yy);
    number.append("/");
    number.append(xx);
   } else {
    this.result = yy + xx;
    number.append(yy);
    number.append("+");
    number.append(xx);
   }
  }
  this.content = number.toString();
  log.info("數字計算公式 {}",this.content);
 }

 private void drawString(Graphics2D g2d,String s,int i) {
  g2d.setFont(new Font("黑體",Font.BOLD,FONT_SIZE));
  int r = RANDOM.nextInt(255);
  int g = RANDOM.nextInt(255);
  int b = RANDOM.nextInt(255);
  g2d.setColor(new Color(r,g,b));
  int x = RANDOM.nextInt(3);
  int y = RANDOM.nextInt(2);
  g2d.translate(x,y);
  int angle = new Random().nextInt() % 15;
  g2d.rotate(angle * Math.PI / 180,5 + i * 25,20);
  g2d.drawString(s,30);
  g2d.rotate(-angle * Math.PI / 180,20);
 }

 // 獲取隨機顏色
 private Color color() {
  int r = RANDOM.nextInt(256);
  int g = RANDOM.nextInt(256);
  int b = RANDOM.nextInt(256);
  return new Color(r,b);
 }

 public String content() {
  return content;
 }

 public int result() {
  return result;
 }
}

數字演算法

此程式碼使用了ttf字型字型在此處 https://gitee.com/tothis/java-record/tree/master/src/main/resources/font

package com.example.captcha;

import lombok.SneakyThrows;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * @author 李磊
 * @datetime 2020/7/9 20:16
 * @description
 */
public class NumberCaptcha {
 // 寬度
 private static final int IMAGE_WIDTH = 160;
 // 高度
 private static final int IMAGE_HEIGHT = 40;
 // 字型大小
 private static final int FONT_SIZE = 28;
 // 字型目錄
 private static final String FONT_PATH = "/font/";
 // 字型列表
 private static final String[] FONT_NAMES = {
   "actionj.ttf","epilog.ttf","headache.ttf","lexo.ttf","prefix.ttf","robot.ttf"
 };

 private static final Random RANDOM = new Random();
 // 計算公式
 private String content;
 // 計算結果
 private int result;

 /**
  * 生成隨機驗證碼
  */
 private void createMathChar() {
  StringBuilder number = new StringBuilder();
  int xx = RANDOM.nextInt(10);
  int yy = RANDOM.nextInt(10);
  // 0~3 對應加減乘除
  int round = (int) Math.round(Math.random() * 3);
  if (round == 0) {
   this.result = yy + xx;
   number.append(yy);
   number.append("+");
   number.append(xx);
  } else if (round == 1) {
   this.result = yy - xx;
   number.append(yy);
   number.append("-");
   number.append(xx);
  } else if (round == 2) {
   this.result = yy * xx;
   number.append(yy);
   number.append("x");
   number.append(xx);
  } else {
   // 0不可為被除數 yy對xx取餘無餘數
   if (!(xx == 0) && yy % xx == 0) {
    this.result = yy / xx;
    number.append(yy);
    number.append("/");
    number.append(xx);
   } else {
    this.result = yy + xx;
    number.append(yy);
    number.append("+");
    number.append(xx);
   }
  }

  content = number.append("=?").toString();
 }

 // 獲取隨機顏色
 private Color color() {
  int r = RANDOM.nextInt(256);
  int g = RANDOM.nextInt(256);
  int b = RANDOM.nextInt(256);
  return new Color(r,b);
 }

 /**
  * 隨機畫干擾圓
  *
  * @param num 數量
  * @param g Graphics2D
  */
 private void drawOval(int num,Graphics2D g) {
  for (int i = 0; i < num; i++) {
   g.setColor(color());
   int j = 5 + RANDOM.nextInt(10);
   g.drawOval(RANDOM.nextInt(IMAGE_WIDTH - 25),RANDOM.nextInt(IMAGE_HEIGHT - 15),j,j);
  }
 }

 @SneakyThrows
 private Font font() {
  int index = RANDOM.nextInt(FONT_NAMES.length);
  Font font = Font.createFont(Font.TRUETYPE_FONT,getClass().getResourceAsStream(FONT_PATH + FONT_NAMES[index]))
    .deriveFont(Font.BOLD,FONT_SIZE);
  return font;
 }

 /**
  * 生成驗證碼圖形
  */
 public BufferedImage create() {
  createMathChar();
  char[] chars = content.toCharArray();
  BufferedImage image = new BufferedImage(IMAGE_WIDTH,BufferedImage.TYPE_INT_RGB);
  Graphics2D g2d = (Graphics2D) image.getGraphics();
  // 填充背景
  g2d.setColor(Color.WHITE);
  g2d.fillRect(0,IMAGE_HEIGHT);
  // 抗鋸齒
  g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
  // 畫干擾圓
  drawOval(2,g2d);
  // 畫字串
  g2d.setFont(font());
  FontMetrics fontMetrics = g2d.getFontMetrics();
  // 每一個字元所佔的寬度
  int fx = IMAGE_WIDTH / chars.length;
  // 字元左填充
  int flp = 10;
  for (int i = 0; i < chars.length; i++) {
   String item = String.valueOf(chars[i]);
   g2d.setColor(color());
   // 文字的縱座標
   int fy = IMAGE_HEIGHT - ((IMAGE_HEIGHT - (int) fontMetrics
     .getStringBounds(item,g2d).getHeight()) >> 1);
   g2d.drawString(item,flp + i * fx + 3,fy - 3);
  }
  g2d.dispose();
  return image;
 }

 public String content() {
  return content;
 }

 public int result() {
  return result;
 }
}

測試類

package com.example.captcha;

import com.greenpineyu.fel.FelEngine;
import com.greenpineyu.fel.FelEngineImpl;
import lombok.SneakyThrows;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;

/**
 * @author 李磊
 * @datetime 2020/7/9 20:10
 * @description
 */
public class Main {
 @SneakyThrows
 public static void main(String[] args) {
  // 圖片型別
  String IMAGE_TYPE = "png";
  ChineseCaptcha chinese = new ChineseCaptcha();
  NumberCaptcha number = new NumberCaptcha();

  for (int i = 0; i < 10; i++) {
   BufferedImage image1 = chinese.create();
   // 輸出檔案
   ImageIO.write(image1,IMAGE_TYPE,new File("D:/data/a" + i + ".png"));
   System.out.println(chinese.content() + ' ' + chinese.result());

   BufferedImage image2 = number.create();
   // 輸出檔案
   ImageIO.write(image2,new File("D:/data/b" + i + ".png"));
   System.out.println(number.content() + ' ' + number.result());
  }
 }
}

如需要多級運算如1+2-3*4/5 則需要使用表示式引擎計算如下為使用fel計算表示式

// fel計算表示式
FelEngine fel = new FelEngineImpl();
System.out.println(3 * 2 + 1);
System.out.println(fel.eval("3*2+1"));
System.out.println(3 * (2 + 1));
System.out.println(fel.eval("3*(2+1)"));

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