Java swing random verification code

Public? Static electricity Invalid? processRequest(http servlet request？ Request,

HttpServletResponse？ Response)? Throwing? ServletException，？ IOException？ {

?

? response . setcontenttype(" image/JPEG ")；

? Response.setHeader("Pragma ","no cache ");

? Response.setheader ("cache-control", "no cache");

? response . setdate header(" Expires "，0);

? HttpSession？ Conversation? =? request . getsession()；

?

? int？ Width? =? 60,? Height? =? 20;

?

? BufferedImage？ Image? =? New? BufferedImage (width, height,

BufferedImage。 TYPE _ INT _ RGB)；

?

? //? Get graphic context

? Graphics? g？ =? image . get graphics()；

?

? //? Generate random class

? Random? Random? =? New? random()；

?

? //? Set the background color.

? g.setColor(getRandColor(200，？ 250));

? g.fillRect(0，？ 0,? Width? Height);

?

? //? Set font

? G.setFont (new? Font("Times？ New? Roman? Font. Flat and faint? 18));

?

? //? 155 interference line is generated randomly, which makes the authentication code in the image difficult to be detected by other programs.

? g . set color(getRandColor( 160，？ 200));

? For what? (int？ Me? =? 0; ? Me? & lt？ 155; ? i++)？ {

int？ x？ =? Random.nextInt (width);

int？ y？ =? Random.nextInt (height);

int？ xl？ =? random . nextint( 12)；

int？ yl？ =? random . nextint( 12)；

g.drawLine(x，y，？ x？ +? xl，？ y？ +? yl)；

? }

?

? //? Take the randomly generated authentication code (4 digits)

? String? sRand？ =? "";

? For what? (int？ Me? =? 0; ? Me? & lt？ 4; ? i++)？ {

String? Rand? =? string . value of(random . nextint( 10))；

sRand？ +=? Rand;

//? Display the verification code to the image.

G.setColor (new? Color (20? +? random.nextInt( 1 10)，？ 20? +? at will

? . nextInt( 1 10)，？ 20? +? random . nextint( 1 10)))； //? Call functions are all the same color, probably because the seeds are too close, so they can only be generated directly.

G. draw rope (rand, 13? *? Me? +? 6,? 16);

? }

?

? //? Store the authentication code in the session.

? session.setAttribute("rand "，sRand)；

? //? Image verification

? g . dispose()；

? ServletOutputStream？ responseOutputStream？ =? response . get output stream()；

? //? Output the image to the page

? ImageIO.write(image，？ “JPEG”，？ responseOutputStream)；

?

? //? Close the input stream below!

? responseoutputstream . flush()；

? responseoutputstream . close()；

? }

?

Static electricity Color? getRandColor(int？ fc，？ int？ bc)？ {

? //? Gets a random color in a given range.

? Random? Random? =? New? random()；

? What if? (fc？ & gt？ 255)

fc？ =? 255;

? What if? (BC? & gt？ 255)

BC? =? 255;

? int？ r？ =? fc？ +? random.nextInt(bc？ -? fc)；

? int？ g？ =? fc？ +? random.nextInt(bc？ -? fc)；

? int？ b？ =? fc？ +? random.nextInt(bc？ -? fc)；

? Return? New? Color (r, g,? b)；

? }

?

? /**?

? *? Handle? That? HTTP？ Get? Method. ?

? *

? *? @param？ Request?

? *servlet？ Request?

? *? @param？ Response?

? *servlet？ Response?

? */?

? Protected? Invalid? doGet(HttpServletRequest？ Request,

HttpServletResponse？ Response)? Throwing? ServletException，？ IOException？ {

? ProcessRequest (request, response);

? } This is the verification code used in my web. You can change it.