Jsp implementation generates the Chinese flag image effect code, jsp flag

Jsp implementation generates the Chinese flag image effect code, jsp flag

This example describes how to use jsp to generate a Chinese flag image. We will share this with you for your reference. The details are as follows:

The image is as follows:

The Code is as follows:

<% @ Page language = "java" import = "java. util. * "pageEncoding =" UTF-8 "%> <% @ page contentType =" image/jpeg "import =" java. awt. *, java. awt. image. *, java. util. *, javax. imageio. *, java. awt. shape. *, java. awt. geom. *, com.sun.image.codec.jpeg. * "%> <% out. clear (); response. setContentType ("image/jpeg"); response. setHeader ("Pragma", "No-cache"); response. setHeader ("Cache-Control", "no-cache"); response. setDateHeader ("Expi Res ", 0); int width = 300; int height = width/3*2; double maxR = 0.15, minR = 0.05; double maxX = 0.50, maxY = 0.50; double [] minX = {0.75, 0.85, 0.85, 0.75}; double [] minY = {0.35, 0.45, 0.60, 0.70}; BufferedImage image = new BufferedImage (width, height, bufferedImage. TYPE_INT_RGB); java. awt. graphics2D g = (java. awt. graphics2D) image. createGraphics (); g. clearRect (0, 0, width, height); g. setRenderingHin T (RenderingHints. KEY_ANTIALIASING, RenderingHints. VALUE_ANTIALIAS_ON); // draw a chess face g. setColor (java. awt. color. red); g. fillRect (0, 0, width, height); // g. fillRect (50, 50, width, height); g. setColor (java. awt. color. yellow); // draw the star double ox = height * maxX, oy = height * maxY; g. fill (createPentacle (ox, oy, height * maxR,-Math. PI/2); // draw a small pentagram for (int idx = 0; idx <4; idx ++) {double sx = minX [idx] * height, sy = minY [I Dx] * height; double theta = Math. atan2 (oy-sy, ox-sx); g. fill (createPentacle (sx, sy, height * minR, theta);} g. dispose (); out. clearBuffer (); out = pageContext. pushBody (); // ImageIO. write (image, "JPEG", response. getOutputStream (); ServletOutputStream outStream = response. getOutputStream (); required imageencoder encoder = required codec. createJPEGEncoder (outStream); encoder. encode (image); outStream. close (); %> <%! Public static java. awt. shape createPentacle (double sx, double sy, double radius, double theta) {final double arc = Math. PI/5; final double rad = Math. sin (Math. PI/10)/Math. sin (3 * Math. PI/10); GeneralPath path = new GeneralPath (); path. moveTo (1, 0); for (int idx = 0; idx <5; idx ++) {path. lineTo (rad * Math. cos (1 + 2 * idx) * arc), rad * Math. sin (1 + 2 * idx) * arc); path. lineTo (Math. cos (2 * (idx + 1) * arc), Math. sin (2 * (idx + 1) * arc);} path. closePath (); AffineTransform atf = AffineTransform. getScaleInstance (radius, radius); atf. translate (sx/radius, sy/radius); atf. rotate (theta); return atf. createTransformedShape (path) ;}%>

Save the code as a jsp file and place it in the running directory.

Code passed the test in tomcat6.0

I hope this article will help you with JSP program design.