标签：width 大小 inpu equals ida 大小写 java.awt 而不是 drawrect
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> ${MessageIfo} <form action="<%=request.getContextPath()%>/checkCodeServlet" method="post"> Username:<input type="text" name="username"/> <br><br> 验证码：<input type="text" name="checkCode"/> <br><br> <img src="<%=request.getContextPath()%>/validateColorServlet"> <br><br> <input type="submit" value="登录"/> </form> </body> </html>
package yang.mybatis.servlet.checkCode; import java.awt.Color; import java.awt.Font; import java.awt.Graphics2D; import java.awt.image.BufferedImage; import java.io.IOException; import java.util.Random; 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; /** * Created by yangshijing on 2017/11/23 0023. */ public class ValidateColorServlet extends HttpServlet { public static final String CHECK_CODE_KEY = "CHECK_CODE_KEY"; private static final long serialVersionUID = 1L; //设置验证图片的宽度, 高度, 验证码的个数 private int width = 152; private int height = 40; private int codeCount = 4; //验证码字体的高度 private int fontHeight = 4; //验证码中的单个字符基线. 即：验证码中的单个字符位于验证码图形左上角的 (codeX, codeY) 位置处 private int codeX = 0; private int codeY = 0; //验证码由哪些字符组成 char [] codeSequence = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz23456789".toCharArray(); //初始化验证码图形属性 public void init(){ fontHeight = height - 2; codeX = width / (codeCount + 2); codeY = height - 4; } public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //定义一个类型为 BufferedImage.TYPE_INT_BGR 类型的图像缓存 BufferedImage buffImg = null; buffImg = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR); //在 buffImg 中创建一个 Graphics2D 图像 Graphics2D graphics = null; graphics = buffImg.createGraphics(); //设置一个颜色, 使 Graphics2D 对象的后续图形使用这个颜色 graphics.setColor(Color.WHITE); //填充一个指定的矩形: x - 要填充矩形的 x 坐标; y - 要填充矩形的 y 坐标; width - 要填充矩形的宽度; height - 要填充矩形的高度 graphics.fillRect(0, 0, width, height); //创建一个 Font 对象: name - 字体名称; style - Font 的样式常量; size - Font 的点大小 Font font = null; font = new Font("", Font.BOLD, fontHeight); //使 Graphics2D 对象的后续图形使用此字体 graphics.setFont(font); graphics.setColor(Color.BLACK); //绘制指定矩形的边框, 绘制出的矩形将比构件宽一个也高一个像素 graphics.drawRect(0, 0, width - 1, height - 1); //随机产生 15 条干扰线, 使图像中的认证码不易被其它程序探测到 Random random = null; random = new Random(); graphics.setColor(Color.GREEN); for(int i = 0; i < 15; i++){ int x = random.nextInt(width); int y = random.nextInt(height); int x1 = random.nextInt(20); int y1 = random.nextInt(20); graphics.drawLine(x, y, x + x1, y + y1); } //创建 randomCode 对象, 用于保存随机产生的验证码, 以便用户登录后进行验证 StringBuffer randomCode; randomCode = new StringBuffer(); for(int i = 0; i < codeCount; i++){ //得到随机产生的验证码数字 String strRand = null; strRand = String.valueOf(codeSequence[random.nextInt(36)]); //把正在产生的随机字符放入到 StringBuffer 中 randomCode.append(strRand); //用随机产生的颜色将验证码绘制到图像中 graphics.setColor(Color.BLUE); graphics.drawString(strRand, (i + 1)* codeX, codeY); } //再把存放有所有随机字符的 StringBuffer 对应的字符串放入到 HttpSession 中 request.getSession().setAttribute(CHECK_CODE_KEY, randomCode.toString()); //禁止图像缓存 response.setHeader("Pragma", "no-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); //将图像输出到输出流中 ServletOutputStream sos = null; sos = response.getOutputStream(); ImageIO.write(buffImg, "jpeg", sos); sos.close(); } }
package yang.mybatis.servlet.checkCode; 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 java.io.IOException; /** * Created by yangshijing on 2017/11/23 0023. */ public class CheckCodeServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request,response); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { HttpSession session = request.getSession(); String check_code_key = (String)session.getAttribute("CHECK_CODE_KEY"); String checkCode = request.getParameter("checkCode"); //不区分大小写 if(check_code_key != null && !check_code_key.trim().equals("")){ check_code_key = check_code_key.toLowerCase(); } if (checkCode != null && !checkCode.trim().equals("")){ checkCode = checkCode.toLowerCase(); } //验证码为NULL或者两者不等，重定向到信息提示页面 if(check_code_key == null || checkCode == null && !check_code_key.equals(checkCode)){ request.getSession().setAttribute("MessageIfo","验证不一致"); response.sendRedirect(request.getContextPath()+"/jsp/checkCode/index.jsp"); return; } //如果两个验证码一致，处理该表单请求,并移除sesssion域中的属性值 session.removeAttribute("CHECK_CODE_KEY"); response.sendRedirect(request.getContextPath()+"/jsp/token/success.jsp"); } }
标签：width 大小 inpu equals ida 大小写 java.awt 而不是 drawrect
原文地址：http://www.cnblogs.com/realshijing/p/7884709.html
