jsp登陸驗證，網頁登陸驗證帶驗證碼校驗，登錄功能之添加驗證碼
part_1：專門用於生成一個驗證碼圖片的類:VerificationCode.Java
package cn.mike.javase.test;
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.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
import org.junit.Test;
/**
* @author : Administrator
* @function : 這是用來測試隨機生成驗證碼圖片的類；
*/
public class VerificationCode {
/**
* 單元測試，試一下能不能自動生成驗證碼圖片
*/
// 這個函數是單元測試時使用的，這裡private一下外面就調用不到了；
/* @Test */
/* public */private void test_fun() {
VerificationCode vc = new VerificationCode();
BufferedImage image = vc.getImage();
try {
// 生成驗證碼圖片，並保存到指定的路徑
VerificationCode.output(image, new FileOutputStream(new File(
".\\image\\vcode_2.jpg")));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
// 將隨機生成的文本內容輸出到控制台，用於校驗
System.out.println(vc.getText());
}
private int w = 70;// 寬
private int h = 35;// 高
private String text;// 文本內容(驗證碼字符串)
private Random r = new Random();
private String[] fontNames = { "宋體", "華文楷體", "黑體", "微軟雅黑", "楷體_GB2312" };
// 隨機字符集合中不包括0和o，O，1和l，因為這些不易區分
private String codes = "23456789abcdefghijkmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYXZ";
// 驗證碼圖片的背景色：白色
private Color bgColor = new Color(255, 255, 255);
/**
* 返回一個驗證碼圖片buffer對象：BufferedImage
*/
public BufferedImage getImage() {
BufferedImage image = createImage();
// 獲取繪圖環境（畫筆工具）
Graphics2D g2 = (Graphics2D) image.getGraphics();
// sb ： 用來保存驗證碼字符串文本內容
StringBuilder sb = new StringBuilder();
for (int i = 0; i < 4; ++i) {// 隨機生成4個字符
String s = randomChar() + "";
sb.append(s);
float x = i * 1.0F * w / 4;
g2.setFont(randomFont());
g2.setColor(randomColor());
g2.drawString(s, x, h - 5);
}
this.text = sb.toString();// 記錄驗證碼文本內容
drawLine(image);// 畫干擾線
return image;
}
/**
* @return 獲取驗證碼文本內容
*/
public String getText() {
return text;
}
/**
* @param image
* @param out
* 將文本寫到指定的輸出流。比如本測試中FileOutputStream指定的保存路徑
*/
public static void output(BufferedImage image, OutputStream out) {
try {
ImageIO.write(image, "jpeg", out);
} catch (IOException e) {
e.printStackTrace();
}
}
private void drawLine(BufferedImage image) {
Graphics2D g2 = (Graphics2D) image.getGraphics();
for (int i = 0; i < 3; ++i) {// 畫3條干擾線
int x1 = r.nextInt(w);
int y1 = r.nextInt(h);
int x2 = r.nextInt(w);
int y2 = r.nextInt(h);
g2.setColor(Color.BLUE);
g2.drawLine(x1, y1, x2, y2);
}
}
private Color randomColor() {
int red = r.nextInt(150);
int green = r.nextInt(150);
int blue = r.nextInt(150);
return new Color(red, green, blue);
}
private Font randomFont() {
int index = r.nextInt(fontNames.length);
String fontName = fontNames[index];
int style = r.nextInt(4);
int size = r.nextInt(5) + 24;
return new Font(fontName, style, size);
}
private char randomChar() {
int index = r.nextInt(codes.length());
return codes.charAt(index);
}
private BufferedImage createImage() {
BufferedImage image = new BufferedImage(w, h,
BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = (Graphics2D) image.getGraphics();
g2.setColor(this.bgColor);
g2.fillRect(0, 0, w, h);
return image;
}
}
part_2:登錄界面：Login.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'Login.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<script type="text/javascript">
function _change_verity_code() {
var imgElem = document.getElementById("img_src");
//添加一個請求參數a是因為，通常浏覽器都有緩存，點擊換一張的時候沒反應，所以加一個請求參數，獲取當前請求時間，可以精確到毫秒，所以每次請求的參數都不同，所以浏覽器有緩存也不妨礙；
imgElem.src = "/ServletDemoProject/servlet/GetVerificationCodeServlet?a="
+ new Date().getTime();
}
</script>
</head>
<%
String fdbkMsg = (String) request.getAttribute("fdbkMsg");
if (null == fdbkMsg) {
fdbkMsg = "";
}
%>
<%
Boolean logedIn = (Boolean) session.getAttribute("logedIn");
if (null == logedIn) {
logedIn = false;
} else if (logedIn) {
//如果在本次會話已經登陸，直接重定向到success-page-1
response
.sendRedirect("/ServletDemoProject/LOGIN-DEMO/success-page-1.jsp");
}
%>
<%
String username = "";
Cookie[] cookies = request.getCookies();
if ((null != cookies) && (cookies.length > 0)) {
for (Cookie c : cookies) {
if ("admin".equals(c.getValue())) {
username = "admin";
break;
}
}
}//end if-condition
%>
<body>
<br>
<div align="center">
請登錄:
<br>
<form action="/ServletDemoProject/servlet/LoginVerificationServlet"
method="post">
<div>
用戶名：
<input type="text" name="username" value="<%=username%>" />
<br>
</div>
<div>
密 碼：
<input type="password" name="password" />
<br>
</div>
<div>
驗證碼：
<input type="text" name="code_text" size="3" />
<img src="/ServletDemoProject/servlet/GetVerificationCodeServlet"
id="img_src" />
<a href="javascript:_change_verity_code()">換一張</a>
<br>
</div>
<div>
<font color='red'><%=fdbkMsg%></font>
<br>
</div>
<div>
<input type="submit" value="提交" />
<br>
</div>
</form>
</div>
</body>
</html>
part_3:處理登錄校驗的servlet ：LoginVerificationServlet.java
package cn.mike.servlet.test_1212;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import cn.mike.javase.test.VerificationCode;
public class GetVerificationCodeServlet extends HttpServlet {
private static final long serialVersionUID = -3520994675366100452L;
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 1.新建一個VerificationCode類；
VerificationCode vc = new VerificationCode();
// 2.從VerificationCode類中獲取BufferedImage對象；
BufferedImage bufImage = vc.getImage();
// 3.同時獲取驗證碼中的文本內容，並放到session域中， 用於校驗；
String code_text = vc.getText();
request.getSession().setAttribute("code_text", code_text);
// 4.將生成的圖片輸出到客戶端浏覽器
VerificationCode.output(bufImage, response.getOutputStream());
}// end method-doGet
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// do same as GET-method :
doGet(request, response);
}// end method-doPost
}
part_4:成功登陸後的提示界面1：success-page-1.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'success-page-1.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<%
String username = (String) session.getAttribute("username");
if (null == username) {
//如果username為空值，說明不是通過正常渠道來的，轉發到Login頁面；
request.setAttribute("fdbkMsg", "別想走後門進來，趕緊登錄！");
request.getRequestDispatcher("/LOGIN-DEMO/Login.jsp").forward(
request, response);
}
%>
<body>
<br>
<%=username%>已經成功登陸。
<br>
<font>您可以選擇浏覽：</font>
<br>
<a href="/ServletDemoProject/LOGIN-DEMO/success-page-2.jsp">點這兒有精彩.</a>
<br>
<a href="/ServletDemoProject/LOGIN-DEMO/success-page-2.jsp">點這兒更精彩.</a>
<br />
<a href="/ServletDemoProject/LOGIN-DEMO/success-page-2.jsp">你敢點這兒嗎.</a>
<br />
</body>
</html>
part_5:成功登陸後的提示界面1：success-page-2.jsp
<%@ page language="java" import="java.util.Date" pageEncoding="UTF-8"%>
<%@ page language="java" import="java.text.SimpleDateFormat"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'success-page-2.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<%
String username = (String) session.getAttribute("username");
if (null == username) {
request.setAttribute("fdbkMsg", "呵呵嗒，這裡是你來的地方嗎？快登陸！");
//轉發到登錄界面:
request.getRequestDispatcher("/LOGIN-DEMO/Login.jsp").forward(
request, response);
}
SimpleDateFormat sDateFormat = new SimpleDateFormat("a");
Date today = new Date();
String am_pm_str = sDateFormat.format(today);
String am_pm_str_in_chinese = "";
if ("am".equalsIgnoreCase(am_pm_str)) {
am_pm_str_in_chinese = "上午";
} else
am_pm_str_in_chinese = "下午";
// set null;
sDateFormat = null;
today = null;
am_pm_str = null;
%>
<body>
<br />
<font><b><%=username%><%=am_pm_str_in_chinese%>好，能來到頁面2真不簡單.</b>
</font>
</body>
</html>
以上所述是小編給大家介紹的JSP實現登錄功能之添加驗證碼，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復大家的。在此也非常感謝大家對網站的支持！
