实现JAVA验证码

1、yanZm.jsp: function changeImg() var a=document.getElementById(mySpan); a.innerHTML= ; /?mySpan? servlet:ImageServlet.javapackage com.servlet; public class ImageServlet extends HttpServlet private static final long serialVersionUID = 1L; public void doGet(HttpServletRequest request, HttpServletRespon

2、se response) throws ServletException, IOException doPost(request, response); public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException int width=150;/ int height=60;/ BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_3BYTE_B

3、GR); Graphics g=image.getGraphics(); Random random=new Random();/ g.setColor(getRandColor(200,250);/ g.fillRect(0, 0, width, height);/ g.setColor(getRandColor(0,255);/ g.drawRect(0, 0, width-1, height-1);/ g.setColor(getRandColor(160,200);/ 5 for(int i=0;i8;i+) int x=random.nextInt(width); int y=ran

4、dom.nextInt(height); int x1=random.nextInt(width); int y1=random.nextInt(height); g.drawLine(x, y, x1, y1); g.setColor(getRandColor(160,200);/ 100 for(int i=0;i100;i+) int x=random.nextInt(width); int y=random.nextInt(height); g.drawLine(x, y, x, y); Font font = new Font(Times New Roman, Font.ITALIC

5、,38); / g.setFont(font);/ int length = 6; / 4 String s=abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789; / :a-z0-9 String sRand=; / / () / g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110); for(int i=0;i255) upper=255; if(upper1) upper=1; if(lowe

6、r255) lower=255; int r=lower+random.nextInt(upper-lower); int g=lower+random.nextInt(upper-lower); int b=lower+random.nextInt(upper-lower); return new Color(r,g,b); resultServlet.javapackage com.servlet;public class resultServlet extends HttpServlet public void doGet(HttpServletRequest request, Http

7、ServletResponse response) throws ServletException, IOException doPost(request, response); public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException response.setContentType(text/html;charset=utf-8); String validateC = (String)request.getSession(

8、).getAttribute( checkCode); String veryCode = request.getParameter(txtyzm); PrintWriter out = response.getWriter(); if (veryCode = null | .equals(veryCode) out.print(); out.println(alert(); out.print(); else if (validateC.equals(veryCode) out.print(); out.println(alert(); out.print(); else out.print(); out.println(alert(); out.print(); out.flush(); out.c