java驗證碼的實現
阿新 • • 發佈:2019-01-04
package com.spring.controller; import java.awt.Color; import java.awt.Font; import java.awt.Graphics2D; import java.awt.image.BufferedImage; 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; import javax.servlet.http.HttpSession; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; @Controller public class VerifyCodeServlet extends HttpServlet { // 驗證碼圖片的寬度。 private int width = 60; // 驗證碼圖片的高度。 private int height = 20; // 驗證碼字元個數 private int codeCount = 4; private int x = 0; // 字型高度 private int fontHeight; private int codeY; char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' }; /** * 初始化驗證圖片屬性 */ public void initxuan() throws ServletException { // 從web.xml中獲取初始資訊 // 寬度 String strWidth ="80"; // 高度 String strHeight ="30"; // 字元個數 String strCodeCount = "4"; // 將配置的資訊轉換成數值 try { if (strWidth != null && strWidth.length() != 0) { width = Integer.parseInt(strWidth); } if (strHeight != null && strHeight.length() != 0) { height = Integer.parseInt(strHeight); } if (strCodeCount != null && strCodeCount.length() != 0) { codeCount = Integer.parseInt(strCodeCount); } } catch (NumberFormatException e) { } x = width / (codeCount + 1); fontHeight = height - 2; codeY = height - 4; } @RequestMapping(value="xuan/verifyCode",method=RequestMethod.GET) public void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, java.io.IOException { initxuan(); // 定義影象buffer BufferedImage buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = buffImg.createGraphics(); // 建立一個隨機數生成器類 Random random = new Random(); // 將影象填充為白色 g.setColor(Color.WHITE); g.fillRect(0, 0, width, height); // 建立字型,字型的大小應該根據圖片的高度來定。 Font font = new Font("Fixedsys", Font.PLAIN, fontHeight); // 設定字型。 g.setFont(font); // 畫邊框。 g.setColor(Color.BLACK); g.drawRect(0, 0, width - 1, height - 1); // 隨機產生160條幹擾線,使圖象中的認證碼不易被其它程式探測到。 g.setColor(Color.BLACK); for (int i = 0; i < 10; 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); } // randomCode用於儲存隨機產生的驗證碼,以便使用者登入後進行驗證。 StringBuffer randomCode = new StringBuffer(); int red = 0, green = 0, blue = 0; // 隨機產生codeCount數字的驗證碼。 for (int i = 0; i < codeCount; i++) { // 得到隨機產生的驗證碼數字。 String strRand = String.valueOf(codeSequence[random.nextInt(36)]); // 產生隨機的顏色分量來構造顏色值,這樣輸出的每位數字的顏色值都將不同。 red = random.nextInt(255); green = random.nextInt(255); blue = random.nextInt(255); // 用隨機產生的顏色將驗證碼繪製到影象中。 g.setColor(new Color(red, green, blue)); g.drawString(strRand, (i + 1) * x, codeY); // 將產生的四個隨機數組合在一起。 randomCode.append(strRand); } // 將四位數字的驗證碼儲存到Session中。 HttpSession session = req.getSession(); session.setAttribute("validateCode", randomCode.toString()); // 禁止影象快取。 resp.setHeader("Pragma", "no-cache"); resp.setHeader("Cache-Control", "no-cache"); resp.setDateHeader("Expires", 0); resp.setContentType("image/jpeg"); // 將影象輸出到Servlet輸出流中。 ServletOutputStream sos = resp.getOutputStream(); ImageIO.write(buffImg, "jpeg", sos); sos.close(); } }
package com.spring.controller; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; @Controller public class ResultServlet { @RequestMapping(value="resultServlet/validateCode",method=RequestMethod.POST) public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=utf-8"); String validateC = (String) request.getSession().getAttribute("validateCode"); String veryCode = request.getParameter("c"); PrintWriter out = response.getWriter(); if(veryCode==null||"".equals(veryCode)){ out.println("驗證碼為空"); }else{ if(validateC.equals(veryCode)){ out.println("驗證碼正確"); }else{ out.println("驗證碼錯誤"); } } out.flush(); out.close(); } }
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>test verify code</title>
</head>
<body>
<input id="veryCode" name="veryCode" type="text"/>
<img id="imgObj" alt="" src="xuan/verifyCode"/>
<a href="#" onclick="changeImg()">換一張</a>
<input type="button" value="驗證" onclick="isRightCode()"/>
<div id="info"></div>
</body>
</html>
<script type="text/javascript">
function changeImg(){
var imgSrc = $("#imgObj");
var src = imgSrc.attr("src");
imgSrc.attr("src",chgUrl(src));
}
//時間戳
//為了使每次生成圖片不一致,即不讓瀏覽器讀快取,所以需要加上時間戳
function chgUrl(url){
var timestamp = (new Date()).valueOf();
urlurl = url.substring(0,17);
if((url.indexOf("&")>=0)){
urlurl = url + "×tamp=" + timestamp;
}else{
urlurl = url + "?timestamp=" + timestamp;
}
return url;
}
function isRightCode(){
var code = $("#veryCode").attr("value");
code = "c=" + code;
$.ajax({
type:"POST",
url:"resultServlet/validateCode",
data:code,
success:callback
});
}
function callback(data){
$("#info").html(data);
}
</script>