jsp中生成圖片縮略圖的代碼

2024-09-05 00:19:49

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<%@ 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=============");

    //-----------------------上傳完成，開始生成縮略圖-------------------------
    java.io.file file = new java.io.file("e://1110168154_58348.jpg");//saveurl);        //讀入剛才上傳的文件
    string newurl="e://1110168154_58348_min.jpg";//request.getrealpath("/")+url+filename+"_min."+ext; //新的縮略圖保存地址
    image src = javax.imageio.imageio.read(file);                     //構造image對象
    float tagsize=287;
    int old_w=src.getwidth(null);                                     //得到源圖寬
    int old_h=src.getheight(null);
    int new_w=0;
    int new_h=0;                            //得到源圖長
    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);//計算新圖長寬
    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);       //繪制縮小后的圖
    fileoutputstream newimage=new fileoutputstream(newurl);          //輸出到文件流
    jpegimageencoder encoder = jpegcodec.createjpegencoder(newimage);
    encoder.encode(tag);                                               //近jpeg編碼
     newimage.close();
    /*
    */
%>
</body>
</html>