绚丽多彩的servlet

import java.awt.Color; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.io.IOException; import java.io.OutputStream; import java.io.PrintWriter; import java.util.Random; import javax.servlet.ServletException; import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.sun.image.codec.jpeg.ImageFormatException; import com.sun.image.codec.jpeg.JPEGCodec; import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class ImageServlet extends HttpServlet { private static final int height = 500; private static final int width = 500;

public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("image/jpeg"); BufferedImage image = getImage(); OutputStream os = response.getOutputStream(); JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(os);

try { encoder.encode(image); } catch (IOException e) { os.write(e.getLocalizedMessage().getBytes()); }

}

private BufferedImage getImage() { BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Random r = new Random(); Graphics g = image.getGraphics(); g.setColor(new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255))); g.fillRect(0, 0, width, height); g.setColor(new Color(0, 0, 0)); g.finalize(); return image; }

}

<?xml version="1.0" encoding="GB18030"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <servlet> <servlet-name>ImageServlet</servlet-name> <servlet-class> ImageServlet </servlet-class> </servlet> <servlet-mapping> <servlet-name>ImageServlet</servlet-name> <url-pattern>/image</url-pattern> </servlet-mapping> </web-app>