img.jsp这个是生成验证码的。文件 <%@ page contentType="image/jpeg" import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*" pageEncoding="GB2312"%> <%!//给定范围获得随机颜色 Color getRandColor(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); }%> <% //声明字符串型的arrNumber用于保存产生随机数的数字,其中包括26个英文字母(大写小写)和0-9的数字 String arrNumber = "0123456789"; //设置页面不缓存 response.setHeader("Pragma", "No-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); // 在内存中创建图象 int width = 60, height = 20; BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); // 获取图形上下文 Graphics g = image.getGraphics(); //生成随机类 Random random = new Random(); // 设定背景色 g.setColor(getRandColor(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.setColor(getRandColor(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); } /* 取随机产生的认证码(4位数字)*/ String sRand=""; for (int i=0;i<4;i++){ int rand=random.nextInt(10); sRand+=String.valueOf(arrNumber.charAt(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(String.valueOf(arrNumber.charAt(rand)),13*i+6,16); //g.drawString(rand, 13 * i + 6, 16); } // 将认证码存入SESSION session.setAttribute("rand", sRand); // 图象生效 g.dispose(); // 输出图象到页面 ImageIO.write(image, "JPEG", response.getOutputStream()); out.clear(); out = pageContext.pushBody(); %> 页面调用的时候这么用 <img src="code.jsp?" onclick="this.src+=Math.random();" style="cursor:hand"/>
<%@ page contentType="image/jpeg"
import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"
pageEncoding="GB2312"%>
<%!//给定范围获得随机颜色
Color getRandColor(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);
}%>
<%
//声明字符串型的arrNumber用于保存产生随机数的数字,其中包括26个英文字母(大写小写)和0-9的数字
String arrNumber = "0123456789";
//设置页面不缓存
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
// 在内存中创建图象
int width = 60, height = 20;
BufferedImage image = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
// 获取图形上下文
Graphics g = image.getGraphics();
//生成随机类
Random random = new Random();
// 设定背景色
g.setColor(getRandColor(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.setColor(getRandColor(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);
} /* 取随机产生的认证码(4位数字)*/
String sRand="";
for (int i=0;i<4;i++){
int rand=random.nextInt(10);
sRand+=String.valueOf(arrNumber.charAt(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(String.valueOf(arrNumber.charAt(rand)),13*i+6,16);
//g.drawString(rand, 13 * i + 6, 16);
}
// 将认证码存入SESSION
session.setAttribute("rand", sRand);
// 图象生效
g.dispose();
// 输出图象到页面
ImageIO.write(image, "JPEG", response.getOutputStream());
out.clear();
out = pageContext.pushBody();
%>
页面调用的时候这么用
<img src="code.jsp?" onclick="this.src+=Math.random();" style="cursor:hand"/>
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/*
* 产生图片验证码。
*
*/
public class CodeServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { response.setContentType("image/png"); String code = genCode(); request.getSession().setAttribute("code", code); BufferedImage image = new BufferedImage(80, 30, BufferedImage.TYPE_4BYTE_ABGR);
Graphics2D g = (Graphics2D) image.getGraphics();
g.setColor(new Color(237, 189, 0));
g.drawLine(0, 0, 80, 30);
g.setColor(new Color(160, 139, 57));
Font f = g.getFont();
g.setFont(new Font(f.getFamily(), f.getStyle(), 20));
g.drawString(code, 10, 20); OutputStream out = response.getOutputStream(); ImageIO.write(image, "png", out); out.close(); } private String genCode() {
Random random = new Random();
StringBuilder buf = new StringBuilder();
buf.append((char) ('A' + random.nextInt(26)));
buf.append((char) ('A' + random.nextInt(26)));
buf.append((char) ('A' + random.nextInt(26)));
buf.append((char) ('A' + random.nextInt(26)));
return buf.toString();
} public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}