隨機生成驗證碼

1、ackage login.validate;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.util.Random;import javax.imageio.ImageIO;import javax.imageio.stream.ImageOutputStream;pu

2、blic class RandomNum private ByteArrayInputStream image;/像private String str;/驗證碼/* public static final char code = 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,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; */private RandomNum()init();/初始化屬性/* 取得 RandomNumUtil 實例*/p

3、ublic static RandomNum Instance()return new RandomNum();/*取得驗證碼圖片*/public ByteArrayInputStream getImage()return this.image;/*取得圖片的驗證碼*/public String getString()return this.str;private void init() (/在內(nèi)存中創(chuàng)建圖象int width=65, height=20;Bufferedlmage image = new BufferedImage(width, height, BufferedImage.T

4、YPE_INT_RGB);/獲取圖形上下文Graphics g = image.getGraphics();/生成隨機類Random random = new Random();/設(shè)定背景色g.setColor(getRandColor(200,250);g.fillRect(0, 0, width, height);/設(shè)定字體g.setFont(new Font(Times New Roman,Font.PLAIN,18);/隨機產(chǎn)生155條干擾線，使圖象中的認(rèn)證碼不易被其它程序探測到g.setColor(getRandColor(160,200);for (int i=0;i155;i+)int x = random.nextInt(width);int y = random.nextInt(height);int xl = random.nextInt(12);int yl = random.nextInt(12);g.drawLine(x,y,x+xl,y+yl);/取隨機產(chǎn)生的認(rèn)證碼(4位數(shù)字)String sRand=;for (int i=0;i255) fc=255;if(bc255) bc=255;int r=fc+random.nextInt(bc-fc);int g=fc+r