JSP color verification code

xiaoxiao2021-03-19  189

Generate images with 4 random numbers and messy backgrounds, numbers and background colors will change, the server is refreshing (with history.go (-1) varies)

Prototype Reference Alibaba

http://china.alibaba.com/member/showimage

Generate the file of the verification code ----- image.jsp

<% @ page contenttype = "image / jpeg" import = "java.awt. *, java.awt.image. *, java.util. *, javax.imageio. *"%> <%! Color getrandcolor (int FC) , int BC) {// given 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);}%> <% / / Set the page does not cache Response.setHeader ("prgma", "no-cache"); response.setHeader ("cache-control", "no-cache"); Response.SetDateHeader ("Expires", 0);

// Create image in memory int width = 60, height = 20; bufferedimage image = new bufferedimage (width, height, bufferedimage.type_int_rgb);

/ / Get graphics context graphics g = image.getgraphics ();

/ / Generate random random random = new random ();

// Set the background color G.SetColor (GetrandColor (200, 250)); G.FillRect (0, 0, Width, Height);

// Set the font G.SetFont (New Font ("Times New Roman", Font.Plain, 18));

// Sea Border //g.SetColor (New Color ()); // g.drawRect (0, 0, Width-1, Height-1);

// Randomly generate 155 interference lines, enabling the authentication code in the image to detect G.SetColor (GetrandColor (160, 200)) in the image; for (int = 0; i <155; 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) 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 (20 random.nextint (110), 20 random.nextint (110), 20 random.nextint (110))); /// The color of the call function is the same, it may be because the seed is too close, so only G.DrawString (Rand, 13 * i 6, 16) can only be generated;} // Deposit the authentication code into sessionSession.setttribute ("rand", SRAND);

// Image take effect g.dispose ();

// Output image to page imageio.write (image, "jpeg", response.getoutputstream ());

%>

--------------- Use the verification code picture -------- A.JSP ----------------- -------------------

<% @ Page ContentType = "Text / HTML; Charset = GB2312"%> authentication code input Page </ title> <meta http-equiv = "content-type" content = "text / html; charSet = GB2312"> <meta http-equiv = "pragma" Content = "no-cache"> <meta http-equiv = "Cache-control" content = "no-cache"> <meta http-equiv = "expires" content = "0"> </ head> <body> <form method = post action = "check.jsp"> < Table> <TR> <TD Align = LEFT> The authentication code generated by the system: </ td> <TD> <img border = 0 src = "image.jsp"> </ td> </ tr> <tr> <TD Align = Left> Enter the above authentication code: </ td> <TD> <input type = text name = rand maxlength = 4 value = "> </ td> </ tr> <tr> <td colspan = 2 align = Center> <input type = Submit value = "Submit Detection"> </ td> </ tr> </ form> </ body> </ html></p> <p>----------------- Verified page ---------- Check.jsp <% @ Page ContentType = "Text / HTML; Charset = GB2312" Language = "Java" Import = "java.sql. *" ErrorPage = ""%> <html> <head> <title> authentication code verification page </ title> <meta http-equiv = "content-type" content = "text =" Text / html; charSet = GB2312> <meta http-equiv = "pragma" content = "no-cache"> <meta http-equiv = "cache-control" content = "no-cache"> <meta http-equiv = "Expires" Content = "0"> </ head></p> <p><body> <% string rand = (string) session.getattribute ("rand"); string input = request.getParameter ("rand");%> The authentication code generated by the system is: <% = rand%> <br> authentication code you entered is: <% = input%> <br> <br> <% if (rand.equals (input)) {%> <font color = green> the same input, the authentication is successful! </ font> <%} else {%> <font color = red> Enter different, certification failed! </ font> <%}%> </ body> </ html></p></div><div class="text-center mt-3 text-grey"> 转载请注明原文地址:https://www.9cbs.com/read-130284.html</div><div class="plugin d-flex justify-content-center mt-3"></div><hr><div class="row"><div class="col-lg-12 text-muted mt-2"><i class="icon-tags mr-2"></i><span class="badge border border-secondary mr-2"><h2 class="h6 mb-0 small"><a class="text-secondary" href="tag-2.html">9cbs</a></h2></span></div></div></div></div><div class="card card-postlist border-white shadow"><div class="card-body"><div class="card-title"><div class="d-flex justify-content-between"><div><b>New Post</b>(<span class="posts">0</span>) </div><div></div></div></div><ul class="postlist list-unstyled"> </ul></div></div><div class="d-none threadlist"><input type="checkbox" name="modtid" value="130284" checked /></div></div></div></div></div><footer class="text-muted small bg-dark py-4 mt-3" id="footer"><div class="container"><div class="row"><div class="col">CopyRight © 2020 All Rights Reserved </div><div class="col text-right">Processed: <b>0.042</b>, SQL: <b>9</b></div></div></div></footer><script src="./lang/en-us/lang.js?2.2.0"></script><script src="view/js/jquery.min.js?2.2.0"></script><script src="view/js/popper.min.js?2.2.0"></script><script src="view/js/bootstrap.min.js?2.2.0"></script><script src="view/js/xiuno.js?2.2.0"></script><script src="view/js/bootstrap-plugin.js?2.2.0"></script><script src="view/js/async.min.js?2.2.0"></script><script src="view/js/form.js?2.2.0"></script><script> var debug = DEBUG = 0; var url_rewrite_on = 1; var url_path = './'; var forumarr = {"1":"Tech"}; var fid = 1; var uid = 0; var gid = 0; xn.options.water_image_url = 'view/img/water-small.png'; </script><script src="view/js/wellcms.js?2.2.0"></script><a class="scroll-to-top rounded" href="javascript:void(0);"><i class="icon-angle-up"></i></a><a class="scroll-to-bottom rounded" href="javascript:void(0);" style="display: inline;"><i class="icon-angle-down"></i></a></body></html><script> var forum_url = 'list-1.html'; var safe_token = 'uSlzU8sLqH7GaboW8OKX9slbf7oMReCUq3dxLb0E_2BUnR_2B_2FivcYPcJPYN9M6b6LuQlyMPanUapbQT2HGM3iHtsw_3D_3D'; var body = $('body'); body.on('submit', '#form', function() { var jthis = $(this); var jsubmit = jthis.find('#submit'); jthis.reset(); jsubmit.button('loading'); var postdata = jthis.serializeObject(); $.xpost(jthis.attr('action'), postdata, function(code, message) { if(code == 0) { location.reload(); } else { $.alert(message); jsubmit.button('reset'); } }); return false; }); function resize_image() { var jmessagelist = $('div.message'); var first_width = jmessagelist.width(); jmessagelist.each(function() { var jdiv = $(this); var maxwidth = jdiv.attr('isfirst') ? first_width : jdiv.width(); var jmessage_width = Math.min(jdiv.width(), maxwidth); jdiv.find('img, embed, iframe, video').each(function() { var jimg = $(this); var img_width = this.org_width; var img_height = this.org_height; if(!img_width) { var img_width = jimg.attr('width'); var img_height = jimg.attr('height'); this.org_width = img_width; this.org_height = img_height; } if(img_width > jmessage_width) { if(this.tagName == 'IMG') { jimg.width(jmessage_width); jimg.css('height', 'auto'); jimg.css('cursor', 'pointer'); jimg.on('click', function() { }); } else { jimg.width(jmessage_width); var height = (img_height / img_width) * jimg.width(); jimg.height(height); } } }); }); } function resize_table() { $('div.message').each(function() { var jdiv = $(this); jdiv.find('table').addClass('table').wrap('<div class="table-responsive"></div>'); }); } $(function() { resize_image(); resize_table(); $(window).on('resize', resize_image); }); var jmessage = $('#message'); jmessage.on('focus', function() {if(jmessage.t) { clearTimeout(jmessage.t); jmessage.t = null; } jmessage.css('height', '6rem'); }); jmessage.on('blur', function() {jmessage.t = setTimeout(function() { jmessage.css('height', '2.5rem');}, 1000); }); $('#nav li[data-active="fid-1"]').addClass('active'); </script>