JSP

Adding Verification Code for JSP to Realize Login Function


jsp Login Verification, Web Login Verification with Verification Code Verification, Login Function Added Verification Code

part_1: Class specially used to generate 1 verification code picture: 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 :  This is a class used to test randomly generated verification code pictures;
 */
public class VerificationCode {
  /**
   *  Unit test, try 1 Can you automatically generate verification code pictures under
   */
  //  This function is used in unit testing, and here private1 You can't call it outside;
  /* @Test */
  /* public */private void test_fun() {
    VerificationCode vc = new VerificationCode();
    BufferedImage image = vc.getImage();
    try {
      //  Generate a verification code picture and save it to the specified path
      VerificationCode.output(image, new FileOutputStream(new File(
          ".\\image\\vcode_2.jpg")));
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    }
    //  Output the randomly generated text content to the console for verification
    System.out.println(vc.getText());
  }
  private int w = 70;//  Width
  private int h = 35;//  Gao
  private String text;//  Text content ( Verification code string )
  private Random r = new Random();
  private String[] fontNames = { " Song Style ", " Chinese regular script ", " Blackbody ", " Microsoft Yahei ", " Regular script _GB2312" };
  //  The random character set does not include 0 And o , O , 1 And l Because these are not easy to distinguish
  private String codes = "23456789abcdefghijkmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYXZ";
  //  Background color of verification code picture: white
  private Color bgColor = new Color(255, 255, 255);
  /**
   *  Return 1 Verification code picture buffer Object: BufferedImage
   */
  public BufferedImage getImage() {
    BufferedImage image = createImage();
    //  Get Drawing Environment (Brush Tool)
    Graphics2D g2 = (Graphics2D) image.getGraphics();
    // sb  :   Used to save the text content of the verification code string
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < 4; ++i) {//  Random generation 4 Characters
      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();//  Record the text content of the verification code
    drawLine(image);//  Draw interference lines
    return image;
  }
  /**
   * @return  Get the text content of the verification code
   */
  public String getText() {
    return text;
  }
  /**
   * @param image
   * @param out
   *       Writes text to the specified output stream. For example, in this test FileOutputStream The specified save path
   */
  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) {//  Painting 3 Interference line
      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: Login interface: 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");
    // Add 1 Request parameters a Because, usually browsers have caches, click to change 1 I didn't respond when I was Zhang, so I added 1 Request parameters, get the current request time, can be accurate to milliseconds, so the parameters of each request are different, so the browser has cache does not hinder;
    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) {
      // If you have logged in during this session, redirect directly to 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">
       Please log in :
      <br>
      <form action="/ServletDemoProject/servlet/LoginVerificationServlet"
        method="post">
        <div>
           User name:
          <input type="text" name="username" value="<%=username%>" />
          <br>
        </div>
        <div>
           Dense    Code:
          <input type="password" name="password" />
          <br>
        </div>
        <div>
           Verification code:
          <input type="text" name="code_text" size="3" />
          <img src="/ServletDemoProject/servlet/GetVerificationCodeServlet"
            id="img_src" />
          <a href="javascript:_change_verity_code()"> Change 1 Zhang </a>
          <br>
        </div>
        <div>
          <font color='red'><%=fdbkMsg%></font>
          <br>
        </div>
        <div>
          <input type="submit" value=" Submit " />
          <br>
        </div>
      </form>
    </div>
  </body>
</html>

part_3: servlet for login verification: 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. New 1 A VerificationCode Class;
    VerificationCode vc = new VerificationCode();
    // 2. From VerificationCode Obtain in the class BufferedImage Object;
    BufferedImage bufImage = vc.getImage();
    // 3. At the same time, get the text content in the verification code and put it in session Domain,   Used for verification;
    String code_text = vc.getText();
    request.getSession().setAttribute("code_text", code_text);
    // 4. Output the generated picture to the client browser
    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: Prompt interface after successful login: 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) {
      // If username Is null, indicating that it is not from the normal channel and forwarded to Login Page;
      request.setAttribute("fdbkMsg", " Don't try to come in through the back door, log in quickly! ");
      request.getRequestDispatcher("/LOGIN-DEMO/Login.jsp").forward(
          request, response);
    }
  %>
  <body>
    <br>
    <%=username%> Has successfully landed.
    <br>
    <font> You can choose to browse: </font>
    <br>
    <a href="/ServletDemoProject/LOGIN-DEMO/success-page-2.jsp"> Click here to have wonderful things .</a>
    <br>
    <a href="/ServletDemoProject/LOGIN-DEMO/success-page-2.jsp"> It's more exciting to click here .</a>
    <br />
    <a href="/ServletDemoProject/LOGIN-DEMO/success-page-2.jsp"> Do you dare to light here .</a>
    <br />
  </body>
</html>

part_5: Prompt interface after successful login: 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", " Heheda, is this where you come from? Log in! ");
      // Forward to login interface :
      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 = " Morning ";
    } else
      am_pm_str_in_chinese = " Afternoon ";
    // set null;
    sDateFormat = null;
    today = null;
    am_pm_str = null;
  %>
  <body>
    <br />
    <font><b><%=username%><%=am_pm_str_in_chinese%> OK, you can come to the page 2 It's not easy .</b>
    </font>
  </body>
</html>