java日志与验证码

1、java日志：日志的网上很多也：你自己看看。我们的系统里面一般都是自己写了一个程序。将用户的操作信息，IP，时间，操作内容写入我们数据库里面。Tomcat的日志一般我们用绿色版,它自带有日志功能。java验证码：1 根据一个随机值，生成一个模糊图片，然后将 随机值 封装到session中。1.1 生成图片的类：package com.framework.security;import java.awt.*;import java.awt.image.BufferedImage;import java.io.Serializable;import java.util.Random;/* * 随机

2、验证码 * User: * Date: 2006-11-2 * Time: 11:31:00 * To change this template use File | Settings | File Templates. */public class ImgCheckCode implements Serializable private String charRandomCode = "" private BufferedImage imageRandomCode; private int width; private int height; public ImgChec

3、kCode(int width, int height) this.width = width; this.height = height; create(4); public ImgCheckCode(int width, int height, int length) this.width = width; this.height = height; create(length); public int getWidth() return width; public void setWidth(int width) this.width = width; public int getHei

4、ght() return height; public void setHeight(int height) this.height = height; public String getCharRandomCode() return charRandomCode; public BufferedImage getImageRandomCode() return imageRandomCode; private void create(int length) / 在内存中创建图象 imageRandomCode = new BufferedImage(width, height, Buffer

5、edImage.TYPE_INT_RGB); / 获取图形上下文 Graphics g = imageRandomCode.getGraphics(); /生成随机类 Random random = new Random(); / 设定背景色 g.setColor(getRandomColor(200, 250); g.fillRect(0, 0, width, height); /设定字体 g.setFont(new Font("Times New Roman", Font.PLAIN, 18); / 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到 g.se

6、tColor(getRandomColor(160, 200); for (int i = 0; i < 155; 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); for (int i = 0; i < length; i+) String rand = String.valueOf(random.nextInt(1

7、0); charRandomCode += rand; / 将认证码显示到图象中 g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110);/调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成 g.drawString(rand, 13 * i + 6, 16); g.dispose(); /* * 给定范围获得随机颜色 * * param fc * param bc * return Color */ private Color getRand

8、omColor(int fc, int bc) Random random = new Random(); if (fc > 255) fc = 255; if (bc > 255) bc = 255; int r = fc + random.nextInt(bc - fc); int g = fc + random.nextInt(bc - fc); int b = fc + random.nextInt(bc - fc); return new Color(r, g, b); 2 进入登陆页面时，将生成的图片显示。Action中调用图片生成类。将图片写入response的io流

9、中public void createCheckCode() throws Exception ImgCheckCode check = new ImgCheckCode(60,18);session.setAttribute("charRandomCode",check.getCharRandomCode();ImageIO.write(check.getImageRandomCode(),"JPEG",response.getOutputStream();页面调用：<img src="adminLoginCheckCode.system" />3 拿着用户输入的值和session的值做比较，验证是否正确。 String checkCode = request.getParameter("rando