jsp中生成图片缩略图的代码

jsp中生成图片缩略图的代码2011-07-15
<%@ page contentType="text/html;charset=gb2312" %>
<%@ page language="java" import="java.util.*" %>
<%@ page language="java" import="java.io.*" %>
<%@ page language="java" import="java.awt.*" %>
<%@ page language="java" import="java.awt.image.*" %>
<%@ page language="java" import="com.sun.image.codec.jpeg.*" %>
<！DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
 <title> </title>
 <meta name="generator" content="editplus" />
 <meta name="author" content="Wang Shiqiang" />
 <meta name="keywords" content="Wang Shiqiang" />
 <meta name="description" content="" />
</head>

<body>
<%
  response.setContentType（"text/html;charset=gb2312"）;
  request.setCharacterEncoding（"gb2312"）;

  out.print（"==================Test for thumbtail picture============="）;

  //-----------------------上传完成，开始生成缩略图-------------------------
  java.io.File file = new java.io.File（"E:\1110168154_58348.jpg"）; //saveurl）; //读入刚才上传的文件
  String newurl="E:\1110168154_58348_min.jpg"; //request.getRealPath（"/"）+url+filename+"_min."+ext; //新的缩略图保存地址
  Image src = javax.imageio.ImageIO.read（file）; //构造Image对象
  float tagsize=287;
  int old_w=src.getWidth（null）; //得到源图宽
  int old_h=src.getHeight（null）;
  int new_w=0;
  int new_h=0; //得到源图长
  int tempsize;
  out.print（"<br/>the old width is :"+old_w+" the old height is "+old_h+"<br/>"）;
  float tempdouble;
  if（old_w>old_h）{
   tempdouble=old_w/tagsize;
  }else{
   tempdouble=old_h/tagsize;
  }
  new_w=Math.round（old_w/tempdouble）;
  new_h=Math.round（old_h/tempdouble）; //计算新图长宽
  out.print（"the new width is :"+new_w+" the new height is "+new_h+"<br/>"）;
  BufferedImage tag = new BufferedImage（new_w,new_h,BufferedImage.TYPE_INT_RGB）;
  tag.getGraphics（）.drawImage（src,0,0,new_w,new_h,null）; //绘制缩小后的图
  FileOutputStream newimage=new FileOutputStream（newurl）; //输出到文件流
  JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder（newimage）;
  encoder.encode（tag）; //近JPEG编码
   newimage.close（）;
  /*
  */
%>
</body>
</html>