Flex Image加载Servlet图像流处理

　　Image控件是Flex加载、显示图像的一个控件，当然其也可以加载SWF文件。Image加载图像有3种方式：        1）使用@Embed，该种方式加图像数据直接编译到swf文件中去，加载速度最快，但是其编译后的swf文件较大；     2）使用应用的相对路径     如tomcat下有个应用，flex-demo，假设flex客户端程序是发布到flex-demo的web目录下，若在web目录下有一个/statics/image/home.png文件，则image控件若要加载该文件只要设置其source如下即可：     Source = "statics/image/home.png"，flex application在运行时会自动去服务器加载该文件。     3）使用servlet     使用servlet进行图像加载需要做2个事情：servlet编写和image的source设置为该servlet的mapping url。     Servlet编写：     只要该servlet继承httpservlet即可，要注意的就是response需要输出图片文件流，代码如下： package com.servlet;   import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.OutputStream;   import javax.servlet.ServletConfig; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;   /**  *   * Description:image加载图片Servlet
　　* @author Marcus  * @version $Id: CaptureShowServlet.java,v 0.1 2010-9-27 上午08:19:09 Exp $  */ public class CaptureShowServlet extends HttpServlet{        /**         * Comment for serialVersionUID         */        private static final long serialVersionUID = 1L;          private String picFolder = "d:/pictures";        public void destroy()        {                 super.destroy();        }                public void init(ServletConfig config) throws ServletException{               super.init(config);        }                @Override        public void doGet(HttpServletRequest request, HttpServletResponse response)               throws ServletException, IOException{         String fileName = request.getParameter("fileName");         String mimeType = "image/gif";             // Set content type         response.setContentType(mimeType);              // Set content size         File file = new File(picFolder + File.separator + fileName);         response.setContentLength((int)file.length());         // Open the file and output streams         FileInputStream in = new FileInputStream(file);         OutputStream out = response.getOutputStream();         // Copy the contents of the file to the output stream         byte[] buf = new byte[1024];         int count = 0;         while ((count = in.read(buf)) >= 0) {             out.write(buf, 0, count);         }         in.close();         out.close();        }                public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException           {                 //processRequest(request, response);        } }        Image的source指定：
　　假设servlet的访问地址为http://localhost:8080/servlet/CaptureShowServlet,加载的图片文件名为pic01.jpg，则只要如下设置image的source即可：
　　Source = "http://localhost:8080/servlet/CaptureShowServlet? fileName=pic01.jpg"