java实现一个简单的验证码生成器

Posted 2021-01-20 JavaPanda

　　最近看了网上很多大佬们写的验证码生成，寻思着自己也写一个，话不多说，代码如下：                                                                                                                                                                                                                                                                                                                                                                                                                                        

  1 import java.awt.BasicStroke;
  2 import java.awt.Color;
  3 import java.awt.Font;
  4 import java.awt.Graphics2D;
  5 import java.awt.image.BufferedImage;
  6 import java.io.FileNotFoundException;
  7 import java.io.IOException;
  8 import java.io.OutputStream;
  9 import java.util.Random;
 10 
 11 import javax.imageio.ImageIO;
 12 
 13 public class VerifyCode {
 14     private int width = 90;
 15     private int high = 40;
 16     private Random random = new Random();
 17     private String[] fonts = {"宋体", "微软雅黑", "TimesRoman", "Cambria"};
 18     private String chars = "1234567890";
 19     private String operator = "+-x";
 20     private Color backColor = Color.white;
 21     private String text;
 22     private int no1;
 23     private int no2;
 24     private String op;
 25     
 26     //获取随机颜色
 27     private Color randomColor() 
 28     {
 29         int red = random.nextInt(150);
 30         int green = random.nextInt(150);
 31         int blue =random.nextInt(150);
 32         return new Color(red,green,blue);
 33     }
 34     
 35     //method：获取随机字体
 36     private Font randomFont() 
 37     {
 38         int index = random.nextInt(fonts.length);
 39         String fontName = fonts[index];
 40         int style = random.nextInt(4);
 41         int size = 24+random.nextInt(4);
 42         
 43         return new Font(fontName,style,size);
 44     }
 45     //method：获取随机操作符号
 46     private String randomOperator() 
 47     {
 48         int index = random.nextInt(3);
 49         return operator.charAt(2)+"";
 50     }
 51     
 52     //method：获取随机数字
 53     private String randomNum() 
 54     {
 55         int index = random.nextInt(chars.length());
 56         return chars.charAt(index)+"";
 57     }
 58     
 59     //method：添加干扰线
 60     private void drawLine(BufferedImage image) 
 61     {
 62         int num = 3;
 63         Graphics2D graphic = (Graphics2D)image.getGraphics();
 64         for(int i=0;i<num;i++) 
 65         {
 66             int x1 = random.nextInt(width);
 67             int x2 = random.nextInt(width);
 68             int y1 = random.nextInt(high);
 69             int y2 = random.nextInt(high);
 70             graphic.setColor(this.randomColor());
 71             graphic.setStroke(new BasicStroke(1.5F));
 72             graphic.drawLine(x1,y1,x2,y2);            
 73         }
 74     }
 75     //method：绘制方法
 76     private void drawString(Graphics2D graphics,String s,float position) 
 77     {
 78         graphics.setColor(randomColor());
 79         graphics.setFont(randomFont());
 80         graphics.drawString(s,position,high -5);
 81     }
 82     
 83     //获取图片缓存
 84     public BufferedImage getImage() 
 85     {
 86         BufferedImage bi = new BufferedImage(width,high,BufferedImage.TYPE_INT_RGB);
 87         Graphics2D g2 = (Graphics2D)bi.getGraphics();
 88         g2.setColor(this.backColor);
 89         g2.fillRect(0, 0, 90, 40);
 90         StringBuilder sb = new StringBuilder();
 91         
 92             //获取操作数s1，绘制
 93             String s1 = randomNum();
 94             this.no1 = Integer.parseInt(s1);
 95             float p1 = 5.0F;
 96             sb.append(s1);
 97             drawString(g2,s1,p1);
 98             
 99             
100             //获取操作符oper，绘制
101             String oper = randomOperator().trim();
102             this.op = oper;
103             sb.append(oper);
104             float p2 = 1.0F*width/5;
105             drawString(g2,oper,p2);
106             
107             //获取操作数s2，绘制
108             String s2 = randomNum();
109             this.no2 = Integer.parseInt(s2);
110             float p3 = 2.0F*width/5;
111             sb.append(s2);
112             drawString(g2,s2,p3);
113             
114             //绘制 等号和问号
115             String calculate = "=?";
116             float p4 = 3.0F*width/5;
117             drawString(g2,calculate,p4);
118             
119             //绘制干扰线
120             drawLine(bi);
121             
122             //返回BufferedImage图片
123             return bi;            
124     }
125     
126     //获取算术的运算结果
127     public int getValue() 
128     {
129         int value = 0;
130         switch(this.op)
131         {
132             case "+": value = this.no1+this.no2;break;
133             case "-": value = this.no1-this.no2;break;
134             case "x":value = this.no1*this.no2;break;
135             default :value = 0;
136         }
137         return value;
138     }
139     
140     //将图片缓存bi输出到指定的输出流out
141     public static void output(BufferedImage bi, OutputStream out) 
142             throws FileNotFoundException, IOException
143     {
144         ImageIO.write(bi,"JPEG",out);
145     }
146 }

 测试代码如下：

    @Test
    public void test1() 
    {
        VerifyCode verifyCode = new VerifyCode();
        BufferedImage bi = verifyCode.getImage();
        
        FileOutputStream out;    
        try 
        {
            out = new FileOutputStream("H:\\\\verifyCode.jpg");
            VerifyCode.output(bi, out);
        }catch (Exception e) 
        {
            e.printStackTrace();
        }    
        System.out.println(verifyCode.getValue());    
    }

生成的验证码图片如下：

　　

程序输出结果如下：

18

 

以上，只实现了10以内的加减乘，除法都没有，毕竟作为验证码，除法还要考虑除数非0、整除等内容，因此未添加除法。各位看看就好，水平有限，请多多指教！