java实现一个简单的验证码生成器

　　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：                                                                                                                                                                                                                                                                                                                                                                                                                                        

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

import javax.imageio.ImageIO;

public class VerifyCode {
    private int width = 90;
    private int high = 40;
    private Random random = new Random();
    private String[] fonts = {"宋体", "微软雅黑", "TimesRoman", "Cambria"};
    private String chars = "1234567890";
    private String operator = "+-x";
    private Color backColor = Color.white;
    private String text;
    private int no1;
    private int no2;
    private String op;
    
    //获取随机颜色
    private Color randomColor() 
    {
        int red = random.nextInt(150);
        int green = random.nextInt(150);
        int blue =random.nextInt(150);
        return new Color(red,green,blue);
    }
    
    //method：获取随机字体
    private Font randomFont() 
    {
        int index = random.nextInt(fonts.length);
        String fontName = fonts[index];
        int style = random.nextInt(4);
        int size = 24+random.nextInt(4);
        
        return new Font(fontName,style,size);
    }
    //method：获取随机操作符号
    private String randomOperator() 
    {
        int index = random.nextInt(3);
        return operator.charAt(2)+"";
    }
    
    //method：获取随机数字
    private String randomNum() 
    {
        int index = random.nextInt(chars.length());
        return chars.charAt(index)+"";
    }
    
    //method：添加干扰线
    private void drawLine(BufferedImage image) 
    {
        int num = 3;
        Graphics2D graphic = (Graphics2D)image.getGraphics();
        for(int i=0;i<num;i++) 
        {
            int x1 = random.nextInt(width);
            int x2 = random.nextInt(width);
            int y1 = random.nextInt(high);
            int y2 = random.nextInt(high);
            graphic.setColor(this.randomColor());
            graphic.setStroke(new BasicStroke(1.5F));
            graphic.drawLine(x1,y1,x2,y2);            
        }
    }
    //method：绘制方法
    private void drawString(Graphics2D graphics,String s,float position) 
    {
        graphics.setColor(randomColor());
        graphics.setFont(randomFont());
        graphics.drawString(s,position,high -5);
    }
    
    //获取图片缓存
    public BufferedImage getImage() 
    {
        BufferedImage bi = new BufferedImage(width,high,BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = (Graphics2D)bi.getGraphics();
        g2.setColor(this.backColor);
        g2.fillRect(0, 0, 90, 40);
        StringBuilder sb = new StringBuilder();
        
            //获取操作数s1，绘制
            String s1 = randomNum();
            this.no1 = Integer.parseInt(s1);
            float p1 = 5.0F;
            sb.append(s1);
            drawString(g2,s1,p1);
            
            
            //获取操作符oper，绘制
            String oper = randomOperator().trim();
            this.op = oper;
            sb.append(oper);
            float p2 = 1.0F*width/5;
            drawString(g2,oper,p2);
            
            //获取操作数s2，绘制
            String s2 = randomNum();
            this.no2 = Integer.parseInt(s2);
            float p3 = 2.0F*width/5;
            sb.append(s2);
            drawString(g2,s2,p3);
            
            //绘制 等号和问号
            String calculate = "=?";
            float p4 = 3.0F*width/5;
            drawString(g2,calculate,p4);
            
            //绘制干扰线
            drawLine(bi);
            
            //返回BufferedImage图片
            return bi;            
    }
    
    //获取算术的运算结果
    public int getValue() 
    {
        int value = 0;
        switch(this.op)
        {
            case "+": value = this.no1+this.no2;break;
            case "-": value = this.no1-this.no2;break;
            case "x":value = this.no1*this.no2;break;
            default :value = 0;
        }
        return value;
    }
    
    //将图片缓存bi输出到指定的输出流out
    public static void output(BufferedImage bi, OutputStream out) 
            throws FileNotFoundException, IOException
    {
        ImageIO.write(bi,"JPEG",out);
    }
}

 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！