Use JSP to generate a color Chinese Character Verification Code

<% @ Page Language = "Java" contenttype = "image/JPEG" pageencoding = "UTF-8" %> <br/> <% @ page import = "Java. AWT. color, <br/> JAVA. AWT. font, <br/> JAVA. AWT. graphics, <br/> JAVA. AWT. image. bufferedimage, <br/> javax. imageIO. imageIO, <br/> JAVA. util. random "%> </P> <p> <%! <Br/> // generate a random color. <br/> color getrandcolor (random, int FC, int BC) {<br/> If (FC> 255) fc = 255; <br/> If (BC> 255) BC = 255; <br/> int r = FC + random. nextint (BC-Fc); <br/> int G = FC + random. nextint (BC-Fc); <br/> int B = FC + random. nextint (BC-Fc); <br/> return new color (R, G, B ); <br/>}< br/>%> </P> <p> <% <br/> // set the page to not be cached <br/> response. setheader ("Pragma", "No-Cache"); <br/> response. setheader ("cache-control", "No-Cache"); <br/> response. setdateheader ("expires", 0); </P> <p> // set the image length and width <br/> int width = 176, Height = 30; </P> <p> // set Alternative Chinese characters <br/> string base = "/u7684/u4e00/u4e86/u662f/u6211/u4e0d/u5728/u4eba/u4eec/u6709 /u6765/latest/u8fd9/latest/u7740 "+ <br/>"/u4e2a/u5730/u5230/u5927/u91cc/u8bf4/u5c31/u53bb/u5b50/latest/ examples/u90a3/u8981/Examples "+ <br/>"/u770b/u5929/u65f6/examples/u51fa/examples/u4e48/u8d77/examples/u90fd/u628a/u597d/u8fd8 /u591a/u6ca1 "+ <br/>"/u4e3a/u53c8/u53ef/u5bb6/u5b66/u53ea/u4ee5/u4e3b/latest/u6837/latest/u60f3/latest/ u8001 "+ <br/>"/u4e2d/u5341/u4ece/u81ea/u9762/latest/u5934/u9053/latest/u8d70/u5f88/u50cf/u89c1 "+ <br/> "/u4e24/u7528/u5979/u56fd/u52a8/u8fdb/u6210/u56de/samples/u5bf9/u5f00/u800c/u5df1" + <br/> "/users/u73b0/u5c71/u6c11/u5019/users/u53d1/u5de5/u5411/u4e8b/u547d/users/u6c34/u51e0" + <br/> "/ u4e49/u4e09/u58f0/latest/u9ad8/u624b/u77e5/u7406/u773c/u5fd7/latest/u6218/latest/u95ee "+ <br/> /users/u5403/u505a/u53eb/u5f53/u4f4f/u542c/u9769/users/u5462/users/u5168 "+ <br/>"/u624d/u56db/u5df2/ u6240/examples/u6700/u5149/u4ea7/u60c5/u8def/u5206/u603b/u6761/u767d "+ <br/>"/u8bdd/u4e1c/examples/Examples /u5982/u88ab/u82b1/u53e3/u653e/u513f/u5e38/u6c14/examples/u7b2c "+ <br/>"/examples/u519b/u5427/u6587/examples/ u518d/u679c/u600e/u5b9a/u8bb8/examples/u884c/Examples "+ <br/>"/examples/u98de/u5916/u6811/u00009/examples/u90e8 /users/u5f80/u8239/u671b/u65b0/u5e26/u961f "+ <br/>"/users/u7ad9/u4ee3/u5458/u673a/u66f4/ examples/u60a8/u6bcf/u98ce/u7ea7/u8ddf "+ <br/>"/examples/templates/u5c11/u76f4/u610f/u591c/u6bd4/u9636/Examples /users/u91cd/users/u6597 "+ <br/>"/users/u54ea/u5316/u592a/u6307/u53d8/u793e/u4f3c/u58eb/u8005/users/u77f3/ examples/u65e5/u51b3 "+ <br/>"/u767e/u539f/u62ff/u7fa4/examples/samples/u672c/u601d/u89e3/u7acb/u6cb3/u6751/Examples /u96be "+ <br/>"/u65e9/u8bba/u5417/u6839/u5171/u8ba9/u76f8/u7814/u4eca/users/u5750/u63a5/users" + <br/> "/u4fe1/u89c9/examples/u53cd/examples/u5343/u627e/u4e89/u9886/u6216/u5e08/u7ed3/u5757" + <br /> "/u8dd1/u8c01/u8349/u8d8a/users/u52a0/u811a/u7d27/u7231/users/u9635/u6015/u6708/u9752" + <br/>" /u534a/u706b/u6cd5/u9898/u5efa/u8d76/latest/u5531/u6d77/latest/u5973/latest/u51c6 "+ <br/>"/u5f20/ u56e2/u5c4b/u79bb/u8272/u8138/u7247/u79d1/u5012/u775b/u5229/latest/u521a/latest/u7531 "+ <br/>"/u9001/latest /queues/u8868/u591f/u6574/u8ba4/u54cd/u96ea/u6d41/u672a/u573a/queues "+ <br/>"/u5e76/u5e95/u6df1/queues/ u5e73/latest/u8fd1/u4family/u8f7b/u8bb2/u519c/u53e4 "+ <br/>"/u9ed1/u544a/latest/u62c9/latest/u5440 /users/u6e05/u9633/u7167/u529e/u53f2/u6539/users "+ <br/>"/u753b/u9020/u5634/users/u6cbb/u5317/u5fc5/ examples/u96e8/u7a7f/u5185/u8bc6/examples/u4e1a "+ <br/>"/u83dc/examples/u7761/examples/u5f62/u91cf/u54b1/u89c2 /users/u901a/u51b2/u5408/u7834 "+ <br/>"/u53cb/u5ea6/u672f/u996d/u516c/u65c1/u623f/u6781/users/u67aa/ u8bfb/platform/u91ce "+ <br/>"/u575a/u7a7a/u6536/platform/u81f3/u653f/u57ce/u52b3/u843d/u94b1/platform/u56f4 /users/u80dc/u6559 "+ <br/>"/u70ed/u5c55/u5305/users/u7c7b/u6e10/u5f3a/u6570/u4e61/users/u6027/u97f3/users/ examples/u9645 "+ <br/>"/u65e7/u795e/u5ea7/u7ae0/examples/u7cfb/u4ee4/u8df3/u975e/u4f55/examples/u53d6/Examples "+ <br/>"/users/u68.0/u6389/u5ffd/u79cd/u88c5/u9876/u6025/u6797/u505c/users/u53e5/u533a/u8863/users "+ <br/> "/u62a5/u53f6/u538b/u6162/u53d4/u80cc/u7ec6 "; </P> <p> // length of alternative Chinese characters <br/> int length = base. length (); </P> <p> // create a memory image <br/> bufferedimage image = new bufferedimage (width, height, bufferedimage. type_int_rgb); </P> <p> // obtain the image context <br/> graphics G = image. getgraphics (); </P> <p> // create a random class instance <br/> random = new random (); </P> <p> // set the background color of the image. The background color is lighter. <br/> G. setcolor (getrandcolor (random, 200,250); <br/> G. fillrect (0, 0, width, height); </P> <p> // optional font <br/> string [] fonttypes = {"/u5b8b/u4f53 ", "/u65b0/u5b8b/u4f53", "/u9ed1/u4f53", "/u6977/u4f53", "/u96b6/u4e66"}; <br/> int types = fonttypes. length; </P> <p> // Add noise to the image background <br/> G. setcolor (getrandcolor (random, 160,200); <br/> G. setfont (new font ("Times New Roman", Font. plain, 14); <br/> for (INT I = 0; I <6; I ++) {<br/> G. drawstring ("************************************* ********", 0, 5 * (I + 2 )); <br/>}</P> <p> // obtain the random token of 6 Chinese characters. <br/> string srand = ""; <br/> for (INT I = 0; I <6; I ++) {<br/> int start = random. nextint (length); <br/> string Rand = base. substring (start, start + 1); <br/> srand + = rand; <br/> // set the font color <br/> G. setcolor (getrandcolor (random, 10,150); <br/> // set the font <br/> G. setfont (new font (fonttypes [random. nextint (fonttypeslength)], Font. bold, 18 + random. nextint (6); <br/> // draw the Chinese character on the image <br/> G. drawstring (RAND, 24 * I + 10 + random. nextint (8), 24); <br/>}</P> <p> // Save the authentication code to the session <br/> session. setattribute ("RAND", srand); </P> <p> G. dispose (); </P> <p> // output the image to the page <br/> ImageIO. write (image, "Jpeg", response. getoutputstream (); <br/> %>