java之验证码制作

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;

public class ImgDemo {

public static void main(String []args) throws IOException {
int w =60;
int h =30;
String FILE_NAME = "d:/hello.jpg";
BufferedImage img = new BufferedImage(60, 30, BufferedImage.TYPE_INT_RGB);
Graphics g = img.getGraphics();

//背景
g.setColor(Color.white);
g.fillRect(0, 0, w, h);
//字体
g.setFont(new Font("aa", Font.BOLD, 18));
//输入验证码:4个0~9之间的随机整数
Random r = new Random();
for(int i=0;i<4;i++){
int a = r.nextInt(10);
int y = 10+r.nextInt(20);
Color c= new Color(r.nextInt(255),r.nextInt(255),r.nextInt(255));
g.setColor(c);
g.drawString(""+a, i*16, y);
}
for(int i=0;i<10;i++){
Color c= new Color(r.nextInt(255),r.nextInt(255),r.nextInt(255));
g.setColor(c);
g.drawLine(r.nextInt(w), r.nextInt(h), r.nextInt(w), r.nextInt(h));//画干扰线是为了放黑
}

//把图形刷到 img对象中
g.dispose();//相当于IO中的close()方法带动flush()
ImageIO.write(img, "JPEG", new FileOutputStream(FILE_NAME));
}
}