Servlet combined with HTML for login verification (including CAPTCHA verification) functionality

The servlet generates the verification code and outputs:

@WebServlet (name = "Yzmservlet") public class Yzmservlet extends HttpServlet {private static final int WIDTH = 100;    private static final int HEIGHT = 40;         protected void DoPost (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException {    Doget (Request,response);         } protected void Doget (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException {        Response.setcharacterencoding ("Utf-8");        Response.setcontenttype ("Text/html;charset=utf-8");        Request.setcharacterencoding ("Utf-8");        BufferedImage image=new bufferedimage (width,height, BUFFEREDIMAGE.TYPE_INT_RGB);        Graphics G=image.getgraphics ();        Set Background color g.setcolor (Color.cyan);        Fill background color g.fillrect (0,0,width,height);        Set foreground color G.setcolor (color.black);        Set the font for Fonts font=new font ("imitation", font.bold,20);        G.setfont (font);        Get Verification code int len=4; String ResULt= "";            for (int x=0;x<len;x++) {char c= (char) randomutils.nextint (65,91);        Result=result+c;        } g.drawstring (result,20,20);            Set the interference line for (int i=0;i<10;i++) {int x1= randomutils.nextint (0,width);            int x2= randomutils.nextint (0,width);            int y1= randomutils.nextint (0,height);            int y2= randomutils.nextint (0,height);            Color Color=new Color (randomutils.nextint (0,255), Randomutils.nextint (0,255), Randomutils.nextint (0,255));            G.setcolor (color);        Set line G.drawline (X1,Y1,X2,Y2);        }//Save the acquired verification code to the session HttpSession Session=request.getsession ();        Session.setattribute ("Identifycode", result);        Output Image Bufferedoutputstream Bos=new Bufferedoutputstream (Response.getoutputstream ());        Imageio.write (image, "JPG", BOS);        Imageio.write (image, "JPG", New File ("e:\\b.jpg"));        Bos.flush ();    Bos.close (); }}

The servlet validates the nickname/password/verification code entered in the login interface:

@WebServlet (name = "Identifyyzmservlet") public class Identifyyzmservlet extends HttpServlet {protected void DoPost (HTT Pservletrequest request, HttpServletResponse response) throws Servletexception, IOException {doget (request,respon    SE);          } protected void Doget (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException {         Response.setcharacterencoding ("Utf-8");         Response.setcontenttype ("Text/html;charset=utf-8");         Request.setcharacterencoding ("Utf-8");        Gets the user name entered as String Username=request.getparameter ("username");         Gets the input password String password=request.getparameter ("password");         Gets the input verification code String yzm2=request.getparameter ("yzm01");         Gets the data accessed in the Session object HttpSession session1=request.getsession ();         String yzm1= (String) session1.getattribute ("Identifycode");             if (!username.equals ("") &&!password.equals ("") &&!yzm2.equals ("")) {if (Username.equals ("Bighead")) {if (Password.equals ("4214963")) {if (Yzm1.equals (yzm                         2)) {Response.getwriter (). println ("Login Successful");                     The page//request.getrequestdispatcher ("form01.html") that jumps to after successful login. Forward (request,response);                     } else {Response.getwriter (). println ("The Verification code is wrong, please re-enter");                 }} else {Response.getwriter (). println ("Password is incorrect, please re-enter");             }}else{Response.getwriter (). println ("Wrong nickname, please re-enter");       }}else{Response.getwriter (). println ("the nickname or password or verification code cannot be blank, please enter"); }    }}

Web-xml To configure:

-<servlet><servlet-name>identifyYzmServlet</servlet-name><servlet-class>com.westos.identifyYzmServlet</servlet-class></servlet>-<servlet-mapping><servlet-name>identifyYzmServlet</servlet-name><url-pattern>/ident</url-pattern></servlet-mapping>-<servlet><servlet-name>yzmServlet</servlet-name><servlet-class>com.westos.untitle2.yzmServlet</servlet-class></servlet>-<servlet-mapping><servlet-name>yzmServlet</servlet-name><url-pattern>/yzm01</url-pattern></servlet-mapping>

HTML Implementation Login Interface:

<!    DOCTYPE html>

Servlet combined with HTML for login verification (including CAPTCHA verification) functionality