jsp中生成图片缩略图的代码

2008-02-23 08:13:27来源：互联网阅读 ()

<%@ 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>