checkcodeservlet.java

SSH框架整合... 不错的源码

package com.lideedu.huang.addressBook.utils;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

@SuppressWarnings("serial")
public class CheckCodeServlet extends HttpServlet {
	
	private static int WIDTH=60;
	private static int HEIGHT=20;
	
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		
		HttpSession session = request.getSession();

		response.setContentType("image/jpeg");
		ServletOutputStream sos = response.getOutputStream();
		
		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);
		
		BufferedImage image = new BufferedImage(WIDTH,HEIGHT,BufferedImage.TYPE_INT_RGB);
		Graphics g=image.getGraphics();
		
		//生成随机证码
		char[] rands = generateCheckCode();
		
        //画背景
		drawBackground(g);
		
		//画验证码
		drawRands(g,rands);
		
		g.dispose();
		
		ByteArrayOutputStream bos= new ByteArrayOutputStream();
		ImageIO.write(image,"JPEG",bos);
		byte[] buf = bos.toByteArray();
		response.setContentLength(buf.length);
		sos.write(buf);
		bos.close();
		sos.close();
		
		//验证码保存在session中
		session.setAttribute("checkCode", new String(rands));
	}
 
	//画背景
	private void drawBackground(Graphics g) {
		
		//设置颜色并填充
		g.setColor(new Color(0xDCDCDC));
		g.fillRect(0, 0, WIDTH, HEIGHT);
		
		//在背景色之上循环n个空心的彩色圈
		for(int i=0;i<15;i++){
			int x = (int)(Math.random()*WIDTH);
			int y = (int)(Math.random()*HEIGHT);
			int red = (int)(Math.random()*255);
			int green = (int)(Math.random()*255);
			int blue = (int)(Math.random()*255);			
			//设置颜色,并画圈
			g.setColor(new Color(red,green,blue));
			g.drawOval(x, y,10,10);
		}
	}
	

	//画验证码
	private void drawRands(Graphics g, char[] rands) {
		g.setColor(Color.BLACK);
		g.setFont(new Font(null,Font.ITALIC|Font.BOLD,18));
		g.drawString(""+rands[0], 1, 17);
		g.drawString(""+rands[1], 16, 15);
		g.drawString(""+rands[2], 31, 18);
		g.drawString(""+rands[3], 46, 16);
	}

	//产生随机验证码
	private char[] generateCheckCode() {
		String chars = "0123456789abcdefghijklmnopqrstuvwxyz";
		char[] rands = new char[4];
		for(int i=0;i<4;i++){
			int rand = (int)(Math.random()*36);
			rands[i]=chars.charAt(rand);
		}
		return rands;
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		this.doGet(request, response);
	}
}