<% @ Page ContentType = "Image / JPEG" Import = "java.awt. *,
Java.awt.Image. *, java.util. *, javax.imageio. * "%>
<%
/ / Create image in memory
INT width = 60, height = 20;
BufferedImage Image = New BufferedImage (Width, Height,
BufferedImage.Type_INT_RGB);
/ / Get the graphical context
Graphics g = image.getgraphics ();
// Set the background color
G.SetColor (New Color (0xDCDCDC));
g.fillRect (0, 0, Width, Height);
// Sea Box
g.setcolor (color.ble);
g.drawRect (0, 0, Width-1, Height-1);
// Take the randomly generated authentication code (4 digits)
String Rand = Request.getParameter ("Rand");
Rand = rand.substring (0, rand.indexof ("."));
Switch (rand.length ())
{
Case 1: Rand = "000" rand; Break;
Case 2: Rand = "00" rand; Break;
Case 3: Rand = "0" rand; Break;
Default: rand = rand.substring (0, 4); Break;
}
// Deposit the authentication code into the session
Session.SetaTRibute ("rand", rand);
// Display the authentication code to the image
g.setcolor (color.ble);
Integer tempnumber = new integer (rand);
String numberstr = TEMPNUMBER.TOSTRING ();
G.SetFont (New Font ("Atlantic Inline", Font.Plain, 18));
String str = numberstr.substring (0, 1);
g.drawstring (STR, 8, 17);
Str = NumBerstr.SUBSTRING (1, 2);
g.drawstring (STR, 20, 15);
Str = NumBerstr.substring (2, 3);
g.drawstring (STR, 35, 18);
Str = NumBerstr.substring (3, 4);
g.drawstring (STR, 45, 15);
// randomly generate 88 interference points, so that the authentication code in the image is not easy to be probed by other programs
Random Random = new random ();
For (int i = 0; i <20; i )
{
INT x = random.nextint (width);
INT Y = random.nextint (height);
g.drawoval (X, Y, 0, 0);
}
// Image take effect
g.dispose ();
// Output image to page
Imageio.write (Image, "JPEG", response.getOutputStream ());
%>
