生产验证码的代码

package cn.dl.fanshe;

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

import javax.imageio.ImageIO;

public class VerifyCode {
    private int w = 70;
    private int h = 35;
    private Random r = new Random();
    private String[] fontNames = {"宋体","华文楷体","黑体","微软雅黑","楷体_GB2312"};
    private String codes = "23456789abcdefghijklmnopqrstuvwxyzABCDEFJHIJKLMNPQRSTUVWXYZ";
    private Color bgColor =  new Color(255,255,255);
    private String text;
    
    //设置随机颜色
    private Color randomColor(){
        int red = r.nextInt(150);
        int green = r.nextInt(150);
        int blue = r.nextInt(150);
        return new Color(red,green,blue);
    }
    
    //生成随机的字体
    private Font randomFont(){
        int index = r.nextInt(fontNames.length);
        String fontName = fontNames[index];//生成随机字体名称
        int style = r.nextInt(4);//生成随机样式，0：无样式，1：粗体，2：斜体，3：粗体+斜体
        int size = r.nextInt(4) + 24;//生成随机字号，24~28
        return new Font(fontName,style,size);    
    }
    
    //画干扰线
    private void drawLine (BufferedImage image){
        int num = 3;//一共画3条线
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        for(int i = 0; i < 3; i++){//生成两个点的坐标，两点确定一条线
            int x1 = r.nextInt(w);
            int y1 = r.nextInt(h);
            int x2 = r.nextInt(w);
            int y2 = r.nextInt(h);
            g2.setStroke(new BasicStroke(1.5F));
            g2.setColor(Color.blue);//干扰线是蓝色
            g2.drawLine(x1, y1, x2, y2);//画线
        }
    }
    
    //随机生成一个字符
    private char randomChar(){
        int index = r.nextInt(codes.length());
        return codes.charAt(index);
    }
    //创建BufferedImage
    private BufferedImage createImage(){
        BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = (Graphics2D)image.getGraphics();
        g2.setColor(this.bgColor);
        g2.fillRect(0, 0, w, h);
        return image;
    }
    
    //得到验证码
    public BufferedImage getImage(){
        BufferedImage image = createImage();//创建图片缓冲区
        Graphics2D g2 = (Graphics2D) image.getGraphics();//得到绘制环境
        StringBuilder sb = new StringBuilder();//用来装载生成的验证码文本
        //向图片中画4个字符
        for(int i = 0; i < 4; i++){//循环四次，每次生成一个字符
            String s = randomChar() + "";//随机生成一个字母
            sb.append(s);//把字母添加到sb中
            float x = i *1.0F*w/4;//设置当前字符的x轴
            g2.setFont(randomFont());//设置随机字体
            g2.setColor(randomColor());//设置随机颜色
            g2.drawString(s, x, h-5);//画图
        }
        this.text = sb.toString();//把生成的字符串赋给了this.text
        drawLine(image);//添加干扰线
        return image;
    }
    
    //返回验证码图片上文本
    public String getText(){
        return text;
    }
    
    //保存图片到指定的输出流
    public static void output(BufferedImage image, OutputStream out) throws IOException{
        ImageIO.write(image, "JPEG", out);
    }
}

//测试类
public class TestVerifyCode {
    
    @Test
    public void fun() throws FileNotFoundException, IOException{
        VerifyCode veryficode = new VerifyCode();
        VerifyCode.output(veryficode.getImage(),new FileOutputStream("F:/b.jpg"));
        
        System.out.println(veryficode.getText());
    }
}