makecertpic.java

bbs论坛系统

package struts.business;

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

import javax.imageio.ImageIO;

public class MakeCertPic {
	
	private char mapTable[]={
			'a','b','c','d','e','f',
			'g','h','i','j','k','l',
			'm','n','o','p','q','r',
			's','t','u','v','w','x',
			'y','z','0','1','2','3',
			'4','5','6','7','8','9'
			};
	public String getCertPic(int width,int height,OutputStream os)
	{
		if(width<=0) width=60;
		if(height<=0) height=20;
		BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
		Graphics g=image.getGraphics();
		g.setColor(new Color(0xE0E0E0));
		g.fillRect(0, 0, width, height);
		g.setColor(Color.black);
		g.drawRect(0, 0, width-1, height-1);
		String strEnsure="";
		for(int i=0;i<4;++i)
		{
			strEnsure+=mapTable[(int)(mapTable.length*Math.random())];
		}
		g.setColor(Color.black);
		g.setFont(new Font("Atlantic Inline",Font.PLAIN,18));
		String str=strEnsure.substring(0,1);
		g.drawString(str, 8, 17);
		str=strEnsure.substring(1,2);
		g.drawString(str, 20, 15);
		str=strEnsure.substring(2,3);
		g.drawString(str, 35, 18);
		str=strEnsure.substring(3,4);
		g.drawString(str,45,15);
		
		Random rand=new Random();
		for(int i=0;i<20;i++)
		{
			int x=rand.nextInt(width);
			int y=rand.nextInt(height);
			g.drawOval(x,y,1,1);
		}
		g.dispose();
		try{
			ImageIO.write(image,"JPEG",os);
			
		}
		catch(IOException e){
			
			return "";
		}
	 return strEnsure;	
	}

}