java之驗證碼製作

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);
		//字體
		g.setFont(new Font("aa", Font.BOLD, 18));
		//輸入驗證碼:4個0~9之間的隨機整數
		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));//畫干擾線是爲了放黑
		}
	        
		//把圖形刷到 img對象中
		g.dispose();//相當於IO中的close()方法帶動flush()
		ImageIO.write(img, "JPEG", new FileOutputStream(FILE_NAME));
	}
}