2022年session实现验证码功能 .pdf

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1、session 实现验证码功能1、页面设计login.html Insert title here function change(img)img.src=img.src+?+new Date().getTime();用户名：密码：认证码：2、随机图片的产生ImageServlet public class ImageServlet extends HttpServlet private static final int WIDTH=130;private static final int HEIGHT=30;public void doGet(HttpServletRequest reque

2、st,HttpServletResponse response)throws ServletException,IOException BufferedImage image=new BufferedImage(WIDTH,HEIGHT,BufferedImage.TYPE_INT_RGB);Graphics g=image.getGraphics();setBackground(g);setBorder(g);drawRandomLine(g);名师资料总结-精品资料欢迎下载-名师精心整理-第 1 页，共 4 页 -String random=drawRandomNum(Graphics2D

3、)g);request.getSession().setAttribute(checkcode,random);/response.setHeader(content-type,image/jpeg);/Expires:-1/Cache-Control:no-cache/Pragma:no-cache/下面的代码一定不能少response.setDateHeader(Expires,-1);response.setHeader(Cache-Control,no-cache);response.setHeader(Pragma,no-cache);response.setContentType(

4、image/jpeg);OutputStream out=response.getOutputStream();ImageIO.write(image,jpg,out);private void setBackground(Graphics g)g.setColor(Color.WHITE);g.fillRect(0,0,WIDTH,HEIGHT);private void setBorder(Graphics g)g.setColor(Color.BLUE);g.drawRect(1,1,WIDTH-2,HEIGHT-2);private void drawRandomLine(Graphi

5、cs g)g.setColor(Color.GREEN);for(int i=0;i5;i+)int x1=new Random().nextInt(WIDTH);int y1=new Random().nextInt(HEIGHT);int x2=new Random().nextInt(WIDTH);int y2=new Random().nextInt(HEIGHT);g.drawLine(x1,y1,x2,y2);/u4e00-u9fa5 30*3.14/180 private String drawRandomNum(Graphics2D g)g.setColor(Color.RED

6、);名师资料总结-精品资料欢迎下载-名师精心整理-第 2 页，共 4 页 -g.setFont(new Font(宋体,Font.BOLD,20);String base=u7684u4e00u4e86u662fu6211u4e0du5728u4ebau4eecu6709u6765u4ed6u8fd9u4e0au7740u4e2au5730u5230u5927u91ccu8bf4u5c31u53bbu5b50u5f97u4e5fu548cu90a3u8981u4e0bu770bu5929u65f6u8fc7u51fau5c0fu4e48u8d77u4f60u90fdu628au597du8fd

7、8u591au6ca1u4e3au53c8u53efu5bb6u5b66u53eau4ee5u4e3bu4f1au6837u5e74u60f3u751fu540cu8001u4e2du5341u4eceu81eau9762u524du5934u9053u5b83u540eu7136u8d70u5f88u50cfu89c1u4e24u7528u5979u56fdu52a8u8fdbu6210u56deu4ec0u8fb9u4f5cu5bf9u5f00u800cu5df1u4e9bu73b0u5c71u6c11u5019u7ecfu53d1u5de5u5411u4e8bu547du7ed9u957

8、fu6c34u51e0u4e8cu95eeu4f46u8eabu65b9u5b9eu5403u505au53ebu5f53u4f4fu542cu9769u6253u5462u771fu5168u624du56dbu5df2u6240u654cu4e4bu6700u5149u4ea7uu8ddfu7b11u554au5b69u4e07u5c11u76f4u610fu591cu6bd4u9636u8fdeu8f66u91cdu4fbfu6597u9a6cu54eau5316u592au6307u53d8u793eu4f3cu58ebu8005u5e72u77f3u6ee1u65e5u51b3u76

9、7eu539fu62ffu7fa4u7a76u5404u516du672cu601du89e3u7acbu6cb3u6751u516bu96beu65e9u8bbau5417u6839u5171u8ba9u76f8u7814u4ecau5176u4e66u5750u63a5u5e94u5173u4fe1u89c9u6b65u53cdu5904u8bb0u5c06u5343u627eu4e89u9886u6216u5e08u7ed3u5757u8dd1u8c01uu534au706bu6cd5u9898u5efau8d76u4f4du5531u6d77u4e03u5973u4efbu4ef6u6

10、11fu51c6u5f20u56e2u5c4bu79bbu8272u8138u7247u79d1u5012u775bu5229u4e16u521au4e14u7531u9001u5207u661fu5bfcu665au8868u591fu6574u8ba4u54cdu96eau6d41u672au573au8be5u5e76u5e95u6df1u523bu5e73u4f1fu5fd9u63d0u786eu8fd1u4eaeu8f7bu8bb2u519cu53e4u9ed1u544au754cu62c9u540du5440u571fu6e05u9633u7167u529eu53f2u6539u5

11、386u8f6cu753bu9020u5634u6b64u6cbbu5317u5fc5u670du96e8u7a7fu5185u8bc6u9a8cu4f20u4e1au83dcu722cu7761u5174u5f62u91cfu54b1u89c2u82e6u4f53u4f17u901au51b2u5408u7834u53cbu5ea6u672fu996du516cu65c1u623fu6781u5357u67aau8bfbu6c99u5c81u56f4u5f1fu80dcu6559u70edu5c55u5305u6b4cu7c7bu6e10u5f3au6570u4e61u547cu6027u9

12、7f3u7b54u54e5u9645u65e7u795eu5ea7u7ae0u5e2eu5566u53d7u7cfbu4ee4u8df3u975eu4f55u725bu53d6u5165u5cb8u6562u6389u5ffdu79cdu88c5u9876u6025u6797u505cu606fu53e5u533au8863u822cu62a5u53f6u538bu6162u53d4u80ccu7ec6;StringBuffer sb=new StringBuffer();int x=10;for(int i=0;i4;i+)String ch=base.charAt(new Random()

13、.nextInt(base.length()+;名师资料总结-精品资料欢迎下载-名师精心整理-第 3 页，共 4 页 -sb.append(ch);/写入字之前，设置好旋转int degree=new Random().nextInt()%30;g.rotate(degree*Math.PI/180,x,20);g.drawString(ch,x,20);g.rotate(-degree*Math.PI/180,x,20);x=x+30;return sb.toString();public void doPost(HttpServletRequest request,HttpServletR

14、esponse response)throws ServletException,IOException doGet(request,response);3、验证码的校验SessionDemo1 public class SessionDemo1 extends HttpServlet public void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException request.setCharacterEncoding(UTF-8);/处理注册请求之前，

15、校验认证码是否有效String c_checkcode=request.getParameter(checkcode);String s_checkcode=(String)request.getSession().getAttribute(checkcode);if(c_checkcode!=null&s_checkcode!=null&c_checkcode.equals(s_checkcode)System.out.println(处理注册请求！);else System.out.println(认证码错误！);public void doPost(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException doGet(request,response);名师资料总结-精品资料欢迎下载-名师精心整理-第 4 页，共 4 页 -