jsp显示图像的问题，马上给分！！！！

Question

http://www.csdn.net/oldexpert/TopicView.asp?id=83096&table=200101

Answer 1

<%
/**
 * 文 件 名:showcoverphoto.jsp
 * 显示封面图片
 * 输入参数：bookid.
 */
%>
<%@ page contentType="image/gif;charset=gb2312" %>
<%@ include file="/include/initanonymousportal.jsp"%>
<%@ page import="java.sql.*"%>
<%@ page import="java.io.*"%>
<%@ page import="com.chinabook.module.content.ContentFactory"%>
<%@ page import="com.chinabook.module.content.Book"%>
<%@ page import="com.chinabook.util.web.ParamUtils"%>
<%!private void showImg(InputStream ins,javax.servlet.http.HttpServletResponse response){
    try{
      byte[] buffer = new byte[8000];
      int index=0;
      int len;
      javax.servlet.ServletOutputStream out = response.getOutputStream();
      while((len=ins.read(buffer,index,8000))!=-1){
        out.write(buffer,0,len);
      }
      out.flush();
      out.close();
   }catch(java.io.IOException e){}
}
%>
<%
  //获取参数
  int bookId=ParamUtils.getIntParameter(request,"bookid");  com.chinabook.module.content.ContentFactory
                 contentFactory = portal.getContentFactory();
   com.chinabook.module.content.Book book
                 = contentFactory.getBook(bookId);
   java.io.InputStream inStream = book.getCoverPhoto();
   if(inStream==null){
      inStream = new java.io.FileInputStream(new File("/opt/orion/default-web-app/upload/CoverNo.gif"));//
   }
   showImg(inStream,response);
   try{
      inStream.close();
   }catch(java.io.IOException e){   }
%>