Servlet动态产生JPEG图像的例子

//GenerateImage.java

/* 动态产生JPEG图像的例子 */

import java.awt.*;

import java.awt.image.*;

import com.sun.image.codec.jpeg.*; //编码类

java.util.*;

javax.servlet.*;

javax.servlet.http.*;

java.io.*;

class GenerateImage extends HttpServlet

public void doGet(HttpServletRequest request,HttpServletResponse response)

throws ServletException, java.io.IOException {

response.setContentType("image/jpeg"):

int width=200, height=200;

BufferedImage image = BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);

Graphics g = image.getGraphics();

g.setColor(Color.white);

g.fillRect(0,0,width,heitht);

Polygon poly = new Polygon();

Random random = new Random();

for(int i=0;i<5;i++)

{

poly.addPoint(random.nextInt(width),random.nextInt(height));

}

g.setColor(Color.cyan);

g.fillPolygon(poly);

g.dispose(); //消拙Graphics 对图形没有肖毁

ServletOutputStream sos =response.getOutputStream(); //二进制

JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(sos); //创建编码器,输出到sos那里

encoder.encode(image);

}

public void doPost(HttpServletRequest request,HttpServletResponse response)

throws ServletException, java.io.IOException {

doGet(request,response);

}

}

http://blog.csdn.net/laiahu/archive/2007/01/23/1491681.aspx