package cn.bingou.util;import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
/*** 动态生成图片*/
public class VerifyCode {// {"宋体", "华文楷体", "黑体", "华文新魏", "华文隶书", "微软雅黑", "楷体_GB2312"}private static String[] fontNames = { "宋体", "华文楷体", "黑体", "微软雅黑",  "楷体_GB2312" };// 可选字符//"23456789abcdefghjkmnopqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ";private static String codes = "23456789abcdefghjkmnopqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ";// 背景色private Color bgColor = new Color(255, 255, 255);// 基数(一个文字所占的空间大小)private int base = 30;// 图像宽度private int width = base * 4;// 图像高度private int height = base;// 文字个数private int len = 4;// 设置字体大小private int fontSize = 22;// 验证码上的文本private String text;private BufferedImage img = null;private Graphics2D g2 = null;/*** 生成验证码图片*/public void drawImage(OutputStream outputStream) {// 1.创建图片缓冲区对象, 并设置宽高和图像类型img = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);// 2.得到绘制环境g2 = (Graphics2D) img.getGraphics();// 3.开始画图// 设置背景色
        g2.setColor(bgColor);g2.fillRect(0, 0, width, height);StringBuffer sb = new StringBuffer();// 用来装载验证码上的文本for (int i = 0; i < len; i++) {// 设置画笔颜色 -- 随机// g2.setColor(new Color(255, 0, 0));g2.setColor(new Color(getRandom(0, 150), getRandom(0, 150),getRandom(0, 150)));// 设置字体g2.setFont(new Font(fontNames[getRandom(0, fontNames.length)], Font.BOLD, fontSize));// 旋转文字(-45~+45)int theta = getRandom(-45, 45);g2.rotate(theta * Math.PI / 180, 7 + i * base, height - 8);// 写字String code = codes.charAt(getRandom(0, codes.length())) + "";g2.drawString(code, 7 + i * base, height - 8);sb.append(code);g2.rotate(-theta * Math.PI / 180, 7 + i * base, height - 8);}this.text = sb.toString();// 画干扰线for (int i = 0; i < len + 2; i++) {// 设置画笔颜色 -- 随机// g2.setColor(new Color(255, 0, 0));g2.setColor(new Color(getRandom(0, 150), getRandom(0, 150),getRandom(0, 150)));g2.drawLine(getRandom(0, 120), getRandom(0, 30), getRandom(0, 120),getRandom(0, 30));}/*** 绘制边框*/// 设置边框的颜色
        g2.setColor(Color.GRAY);// 绘制边框g2.drawRect(0, 0, width-1, height-1);// 4.保存图片到指定的输出流try {ImageIO.write(this.img, "JPEG", outputStream);} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e);}finally{// 5.释放资源
            g2.dispose();}}/*** 获取验证码字符串* @return*/public String getCode() {return this.text;}/** 生成随机数的方法*/private static int getRandom(int start, int end) {Random random = new Random();return random.nextInt(end - start) + start;}public static void main(String[] args) throws Exception {VerifyCode vc = new VerifyCode();vc.drawImage(new FileOutputStream("d:/vc.jpg"));System.out.println("执行成功~!");}
}

VerifyCode

    // 为img标签添加一个点击事件$("#valiImage").click(function(){// 每次点击修改src属性的值，在后面拼接一个不同的参数// 获取当前时间的毫秒值表示var timeStr=new Date().getTime();// 将毫秒之直接拼接在url后面，保证每次点击url的值不同var url="/ValiImageServlet?time="+timeStr;// 使用生成的url给img标签的src属性赋值$("#valiImage").attr("src",url);});    

package cn.bingou.web;import java.io.IOException;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;import cn.bingou.util.VerifyCode;public class ValiImageServlet extends HttpServlet {public void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {// 1.接收请求// 2.调用工具类，生成验证码图片VerifyCode vc=new VerifyCode();// 3.将生成的验证码图片存入response实体中
        vc.drawImage(resp.getOutputStream());// 4.控制浏览器不要缓存验证码// 获取验证码字符串String text=vc.getCode();// 将生成的验证码文本输出到控制台System.out.println("text="+text);// 获取用户的Session对象HttpSession session=req.getSession();// 将正确的验证码文本传入Session作用域session.setAttribute("text", text);// 不要缓存验证码resp.setHeader("Pragma", "no-cache");resp.setHeader("Cache-Control", "no-cache");}public void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {doGet(req, resp);}}

package cn.bingou.web;import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;import cn.bingou.util.JDBCUtils;
import cn.bingou.util.WebUtils;public class RegistServlet extends HttpServlet {public void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {// 1.请求乱码问题// 请求乱码-POST请求req.setCharacterEncoding("utf-8");// 应答乱码问题resp.setContentType("text/html;charset=utf-8");// 2.接收表单参数String username = req.getParameter("username");String password = req.getParameter("password");String password2 = req.getParameter("password2");String nickname = req.getParameter("nickname");String email = req.getParameter("email");String valistr = req.getParameter("valistr");// 3.验证表单// 1)非空验证if(WebUtils.isEmpty(username)){ // 用户名为空验证// 向request作用域中添加错误提示信息req.setAttribute("errMsg", "用户名不能为空！");// 将请求转发给regist.jsp，forward()：请求转发req.getRequestDispatcher("/regist.jsp").forward(req, resp);// 如果用户输入为空，直接返回return;}if(WebUtils.isEmpty(password)){ // 密码为空验证req.setAttribute("errMsg", "密码不能为空！");req.getRequestDispatcher("/regist.jsp").forward(req, resp);return;}if(WebUtils.isEmpty(nickname)){ // 昵称为空验证req.setAttribute("errMsg", "昵称不能为空！");req.getRequestDispatcher("/regist.jsp").forward(req, resp);return;}if(WebUtils.isEmpty(email)){ // 邮箱为空验证req.setAttribute("errMsg", "邮箱不能为空！");req.getRequestDispatcher("/regist.jsp").forward(req, resp);return;}// 2)密码一致验证if(!password.equals(password2)){// 如果密码与确认密码不一样，则输出错误req.setAttribute("errMsg", "密码不一致");req.getRequestDispatcher("/regist.jsp").forward(req, resp);return;}// 3)邮箱格式验证// abc@123.163.comString reg="^\\w+@\\w+(\\.\\w+)+$"; if(!email.matches(reg)){req.setAttribute("errMsg", "邮箱格式不符");req.getRequestDispatcher("/regist.jsp").forward(req, resp);return;}// 4)用户名是否存在String sql1="select * from user where username=?";Connection conn = null;PreparedStatement ps = null;ResultSet rs=null;try {conn=JDBCUtils.getConnection();ps=conn.prepareStatement(sql1);ps.setString(1, username);rs=ps.executeQuery();while(rs.next()){ // 寻找用户名，直到找到为止req.setAttribute("errMsg", "用户名已存在");req.getRequestDispatcher("/regist.jsp").forward(req, resp);return;}} catch (SQLException e) {e.printStackTrace();throw new RuntimeException("验证用户名时数据库出现异常："+e.getMessage());} finally{JDBCUtils.close(conn, ps, rs);}// 5)验证码验证if(WebUtils.isEmpty(valistr)){ // 验证码为空验证req.setAttribute("errMsg", "验证码不能为空！");req.getRequestDispatcher("/regist.jsp").forward(req, resp);return;} else{// 验证码不为空，执行验证码内容验证// 获取保存在session中的正确验证码HttpSession session=req.getSession(false);// 如果当前Session没有就为nullboolean flag=true; // 默认验证码没有问题if(session==null && session.getAttribute("text")==null){// 没有session对象，或者session中没有正确的验证码文本flag=false;}else{String text=(String) session.getAttribute("text");if(!valistr.equalsIgnoreCase(text)){// 用户输入的文本和正确文本不一致flag=false;}}if(flag==false){// 向request作用域中添加错误提示信息req.setAttribute("errMsg", "验证码错误");// 将请求转发给regist.jspreq.getRequestDispatcher("/regist.jsp").forward(req, resp);return;}}// 4.数据存入数据库// 验证信息没有问题，将用户提交的注册信息提交到数据库String sql2="insert into user values(null,?,?,?,?)";Connection conn2=null;PreparedStatement ps2=null;try {conn2=JDBCUtils.getConnection();ps2=conn2.prepareStatement(sql2);ps2.setString(1, username);ps2.setString(2, password);ps2.setString(3, nickname);ps2.setString(4, email);ps2.executeUpdate();int i=ps2.executeUpdate();if(i>0){// 保存成功-提示成功信息，定时刷新到首页resp.getWriter().write("<h1 style='text-align:center;color:red'>恭喜您，注册成功！3秒后自动跳转首页</h1>");// 实现定时刷新resp.setHeader("refresh", "3;url="+req.getContextPath()+"/index.jsp");}else{req.setAttribute("errMsg", "注册出现异常，请稍后重试...");req.getRequestDispatcher("/regist.jsp").forward(req, resp);return;}} catch (SQLException e) {e.printStackTrace();throw new RuntimeException("注册数据出现异常："+e.getMessage());} finally{JDBCUtils.close(conn2, ps2, rs);}}public void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {doGet(req, resp);}}