<% @ 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 ();
// graphics2d graphics = image.creategraphics ();
// Set the background color
g.setcolor (color.white);
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);
G.SetFont (New Font ("Times New Roman", Font.Plain, 18));
g.drawstring (rand, 10, 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 <88; i ) {
INT x = random.nextint (width);
INT Y = random.nextint (height);
g.drawline (x, y, x, y);
}
// Image take effect
g.dispose ();
// Output image to page
Imageio.write (Image, "JPEG", response.getOutputStream ());
%>
