Jsp+ajax implementation of local refresh verification code (onblur event triggering more than the test) _jsp programming

The example of this article is about the local refresh verification Code of JSP+AJAX implementation (onblur Event trigger). Share to everyone for your reference, specific as follows:

Foreground Display page:

welcome.jsp

<%@ page language= "java" contenttype= "text/html; Utf-8 "pageencoding=" Utf-8 "%> <!
DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "Http://www.w3.org/TR/html4/loose.dtd" >  

Create a picture page

authcode.jsp

<%@ page contenttype= "image/jpeg" import= "java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*" pageEncoding = "GBK"%> <%!  
  Color Getrandcolor (int fc, int BC) {//The given range gets the random color Random Random = new Random ();  
  if (FC > 255) FC = 255;  
  if (BC > 255) BC = 255;  
  int r = FC + Random.nextint (BC-FC);  
  int g = FC + Random.nextint (BC-FC);  
  int B = FC + Random.nextint (BC-FC);  
 return new Color (R, G, b);  
 }%> <%//Settings page does not cache Response.setheader ("Pragma", "No-cache");  
 Response.setheader ("Cache-control", "No-cache");  
 Response.setdateheader ("Expires", 0);  
 Create image int width = 20 in memory;  
 BufferedImage image = new BufferedImage (width, height, bufferedimage.type_int_rgb);  
 Gets the graphics context Graphics g = image.getgraphics ();  
 Generate Random class Random Random = new Random ();  
 Set Background color G.setcolor (Getrandcolor (200, 250));  
 G.fillrect (0, 0, width, height); Set font g.setfont (new Font ("Times New Roman", Font.plain, 18));  
 Draw a border//g.setcolor (new Color ());  
 G.drawrect (0,0,width-1,height-1);  
 Randomly generated 155 interference lines, so that the authentication code in the image is not easy to be detected by other programs G.setcolor (Getrandcolor (160, 200));  
  for (int i = 0; i < 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); 
 //Take the randomly generated authentication code (4 digits) String SRand = "";  
  for (int i = 0; i < 4; i++) {String rand = string.valueof (Random.nextint (10));  
  SRand + rand; Display the authentication code to the image G.setcolor (new Color (+ random.nextint), + random. Nextint (110))  
  //Call function out of the same color, may be because the seed is too close, so only directly generated g.drawstring (rand, * i + 6, 16); 
 System.out.println (RAND);  
 //The authentication code is stored in session session.setattribute ("code", SRand);  
 Image entry into force g.dispose ();  
Output image to page imageio.write (image, "JPEG", Response.getoutputstream ());

 %>

Ajax Dynamic Validation Page

codevalidate.jsp

<%@ page language= "java" import= "java.util.*,java.util.*,java.text.*,com.neusoft.xkxt.dao.*, Com.neusoft.xkxt.bean.*,com.neusoft.xkxt.util.* "pageencoding=" UTF-8 "%> 
<% 
String Path = Request.getcontextpath (); 
String basepath = request.getscheme () + "://" +request.getservername () + ":" +request.getserverport () +path+ "/"; 
%> 
<% 
 String authcode=request.getparameter ("Authcode"); 
 String code= (String) session.getattribute ("code"); 
 if (authcode.equals (code)) { 
 out.println ("<div class= ' right ' >√</div>");} 
 else{ 
 out.println ("<div class= ' wrong ' > Authenticode incorrect </div>");} 
%>

I hope this article will help you with JSP program design.