给个例子就行
最好给上注释
------解决方案--------------------
- Java code
1、uploadimage.jsp<%@ page contentType="text/html;charset=gb2312" language="java" import="java.io.*,java.awt.Image,java.awt.image.*,com.sun.image.codec.jpeg.*,java.sql.*,com.jspsmart.upload.*,java.util.*,cn.oof.database.*,cn.oof.house.*"%><%SmartUpload mySmartUpload =new SmartUpload();long file_size_max=4000000;String fileName2="",ext="",testvar="";String url="uploadfile/images/"; //应保证在根目录中有此目录的存在//初始化mySmartUpload.initialize(pageContext);//只允许上载此类文件try { mySmartUpload.setAllowedFilesList("jpg,gif");//上载文件 mySmartUpload.upload();} catch (Exception e){%> <SCRIPT language=javascript> alert("只允许上传.jpg和.gif类型图片文件"); window.location='upfile.jsp'; </script><%}try{ com.jspsmart.upload.File myFile = mySmartUpload.getFiles().getFile(0); if (myFile.isMissing()){%> <SCRIPT language=javascript> alert("请先选择要上传的文件"); window.location='upfile.jsp'; </script> <%} else{ //String myFileName=myFile.getFileName(); //取得上载的文件的文件名 ext= myFile.getFileExt(); //取得后缀名 int file_size=myFile.getSize(); //取得文件的大小 String saveurl=""; if(file_size<file_size_max){ //更改文件名，取得当前上传时间的毫秒数值 Calendar calendar = Calendar.getInstance(); String filename = String.valueOf(calendar.getTimeInMillis()); saveurl=request.getRealPath("/")+url; saveurl+=filename+"."+ext; //保存路径 myFile.saveAs(saveurl,mySmartUpload.SAVE_PHYSICAL); //out.print(filename);//-----------------------上传完成，开始生成缩略图------------------------- java.io.File file = new java.io.File(saveurl); //读入刚才上传的文件 String newurl=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=200; 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; 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 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(); } else{ out.print("<SCRIPT language='javascript'>"); out.print("alert('上传文件大小不能超过"+(file_size_max/1000)+"K');"); out.print("window.location='upfile.jsp;'"); out.print("</SCRIPT>"); } }}catch (Exception e){e.toString();}%> 2 upload.htm<html><head><title>请选择上传的图片</title></head> <body><table border="0" align="center" cellpadding="0" cellspacing="0"> <tr> <td height="45" align="center" valign="middle"><form action="uploadimage.jsp" method="post" enctype="multipart/form-data" name="form1">请选择上传的图片 <input type="file" name="file"><input type="submit" name="Submit" value="上传"> </form></td> </tr></table></body></html>