Java Web picture verification feature implementation two

The previous implementation is the simplest picture verification, this article to achieve a complex point: the picture is rotated, and through a registered instance of the image validation nested in the Web page

The code to implement the image rotation function is:

Write the letter string content = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcedfghijklmnopqrstuvwxyz1234567890"; Random random = new random (); Graphics2D graphics2d = (graphics2d) graphics;//set Font color Graphics2d.setcolor (color.red);//Set font and size Graphics2d.setfont ( New Font ("Arial", font.bold), int x=20;int y=20;for (int i = 0; i < 4; i++) {int index = Random.nextint (Content.length () Char letter = Content.charat (index);d ouble jiaodu = random.nextint -30;double theta = Jiaodu/360*2*math.pi; Graphics2d.rotate (theta, x, y), graphics2d.drawstring (letter+ "", X, y), Graphics2d.rotate (-theta, x, y); x = x+20;}

To implement the servlet code with the Rotate Picture verification feature:

Package Com.lsgjzhuwei.servlet.response;import Java.awt.color;import Java.awt.font;import java.awt.Graphics;import Java.awt.graphics2d;import Java.awt.image.bufferedimage;import Java.io.ioexception;import Java.util.Random;import Javax.imageio.imageio;import Javax.servlet.servletexception;import Javax.servlet.annotation.webservlet;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import javax.servlet.http.httpservletresponse;/** * Servlet Implementation class Verificationcode */@WebServlet ( Asyncsupported = true, Urlpatterns = {"/verificationcode"}) public class Verificationcode extends HttpServlet {private St           Atic final Long serialversionuid = 1L;        /** * @see httpservlet#httpservlet () */public Verificationcode () {super (); TODO auto-generated Constructor stub}/** * @see Httpservlet#doget (httpservletrequest request, HttpServletResponse R esponse) */protected void doget (HttpServletRequest request, httpservletresponsE response) throws Servletexception, IOException {//TODO auto-generated method stubint width = 120;int height = 30;//Create a In-Memory cached picture BufferedImage BufferedImage = new BufferedImage (width, height, bufferedimage.type_int_rgb);///Background color// Draw an image through the graphics graphics graphics = Bufferedimage.getgraphics ();//Set Color Graphics.setcolor (color.yellow);// Fill graphics.fillrect (0, 0, width, height);///Draw Border Graphics.setcolor (Color.Blue); graphics.drawrect (0, 0, width-1, HEIGHT-1);//write the letter string content = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcedfghijklmnopqrstuvwxyz1234567890"; Random random = new random (); Graphics2D graphics2d = (graphics2d) graphics;//set Font color Graphics2d.setcolor (color.red);//Set font and size Graphics2d.setfont ( New Font ("Arial", font.bold), int x=20;int y=20;for (int i = 0; i < 4; i++) {int index = Random.nextint (Content.length () Char letter = Content.charat (index);d ouble jiaodu = random.nextint -30;double theta = Jiaodu/360*2*math.pi; Graphics2d.rotate (theta, x, y), graphics2d.drawstring (letter+ "", X, y); graphics2d.rotatE (-theta, x, y); x = x+20;} Draw the disturbance line int x1;int x2;int y1;int y2;graphics.setcolor (Color.light_gray); for (int i = 0;i <50;i++) {x1=random.nextint ( width); x2=random.nextint (width); y1=random.nextint (height); y2=random.nextint (height); Graphics.drawline (x1, y1, x2 , y2);} Output the picture to the browser//the image of the memory is output by the browser output stream into a JPG image imageio.write (bufferedimage, "JPG", Response.getoutputstream ());} /** * @see Httpservlet#dopost (httpservletrequest request, httpservletresponse response) */protected void DoPost ( HttpServletRequest request, HttpServletResponse response) throws Servletexception, IOException {//TODO auto-generated Method stub}}

Here is the new HTML page, and add a simple registration button, the source code is as follows:

<! DOCTYPE html>

The operating interface of the system is as follows:

Here is the function of complex points: Verification code refresh when clicking on the picture Verification code
Modify the HTML page code as follows:
<! DOCTYPE html>



Java Web picture verification feature implementation two