图片上传并生成缩略图

1 .负责处理图处的bean:
// ---------------------------------------------------------------
package bean;

import javax.imageio.ImageIO;
import javax.imageio.IIOException;
import java.awt.image.BufferedImage;
import java.awt.Image;
import java.io.File;
import java.awt.image.AffineTransformOp;
import java.awt.geom.AffineTransform;

public class convertImage {

private String fileInput ;
private String fileOutput ;

public convertImage()
{

}
public String getFileInput() {
return fileInput;
}
public void setFileInput(String fileInput) {
this .fileInput = fileInput;
}
public String getFileOutput() {
return fileOutput;
}
public void setFileOutput(String fileOutput) {
this .fileOutput = fileOutput;
}

public void convert()
{
try {
File fi = new File(fileInput); // 大图文件
File fo = new File(fileOutput); // 将要转换出的小图文件
int nw = 150 ; // 定义宽为150
int nh = 100 ; // 定义高为100
AffineTransform transform = new AffineTransform();
BufferedImage bis = ImageIO.read(fi);
int w = bis.getWidth();
int h = bis.getHeight();

double sx = ( double )nw / w;
double sy = ( double )nh / h ;
// 判断是横向图形还是坚向图形
if ( w > h ) // 横向图形
{
if ( ( int )(sx * h ) > nh ) // 比较高不符合高度要求,就按高度比例
{

sx = sy ;
nw = ( int )(w * sx) ;
}
else
{
sy = sx ;
nh = ( int )( h * sy) ;
}
}
else
{
if ( ( int )(sy * w ) > nw )
{
sy = sx ;
nh = ( int )(h * sy ) ;
}
else
{
sx = sy ;
nw = ( int )(w * sx) ;
}
}

transform.setToScale(sx,sy);
AffineTransformOp ato = new AffineTransformOp(transform, null );
BufferedImage bid = new BufferedImage(nw,nh,BufferedImage.TYPE_3BYTE_BGR);
ato.filter(bis,bid);
ImageIO.write(bid, " jpeg " ,fo);
}
catch (Exception e)
{
e.printStackTrace();
}
}
}

2 .上传文件的upload.jsp
--------------------------------------------------------------------
<% @ taglib uri = " /WEB-INF/struts-html.tld " prefix = " html " %>
<! DOCTYPE HTML PUBLIC " -//W3C//DTD HTML 4.01 Transitional//EN " >
< html >
< head >

< title > My JSP 'upload.jsp' starting page </ title >

< meta http - equiv = " pragma " content = " no-cache " >
< meta http - equiv = " cache-control " content = " no-cache " >
< meta http - equiv = " expires " content = " 0 " >
< meta http - equiv = " keywords " content = " keyword1,keyword2,keyword3 " >
< meta http - equiv = " description " content = " This is my page " >


</ head >

< body >
< html:form action = " /upload.do " enctype = " multipart/form-data " >
< html:file property = " theFileone " />
< html:submit />
</ html:form >

</ body >
</ html >
// ------------------------------------------------------------------------
3 .显示成功页面

// ------------------------------------------------------------------------
<% @ page language = " java " import = " java.util.* " pageEncoding = " UTF-8 " %>
<% @ page contentType = " text/html;charset=GB2312 " %>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + " :// " + request.getServerName() + " : " + request.getServerPort() + path + " / " ;
%>

<! DOCTYPE HTML PUBLIC " -//W3C//DTD HTML 4.01 Transitional//EN " >
< html >
< head >
< base href = " <%=basePath%> " >

< title > My JSP 'display.jsp' starting page </ title >

< meta http - equiv = " pragma " content = " no-cache " >
< meta http - equiv = " cache-control " content = " no-cache " >
< meta http - equiv = " expires " content = " 0 " >
< meta http - equiv = " keywords " content = " keyword1,keyword2,keyword3 " >
< meta http - equiv = " description " content = " This is my page " >


</ head >

< body >
上传成功. < br >
</ body >
</ html >
// ---------------------------------------------------------------------
4 .Action
// Created by MyEclipse Struts
// XSL source (default): platform:/plugin/com.genuitec.eclipse.cross.easystruts.eclipse_4.1.1/xslt/JavaClass.xsl

package com.mk.struts.action;

import java.io. * ;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.upload.FormFile;

import com.mk.struts.form.UploadForm;

import bean.convertImage;

/* *
* MyEclipse Struts
* Creation date: 03-28-2006
*
* XDoclet definition:
* @struts.action validate="true"
*/
public class UploadAction extends Action {

// --------------------------------------------------------- Instance Variables

// --------------------------------------------------------- Methods

/* *
* Method execute
* @param mapping
* @param form
* @param request
* @param response
* @return ActionForward
*/
public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response) {

// TODO Auto-generated method stub
String encoding = request.getCharacterEncoding() ;
if ( (encoding != null ) && (encoding.equalsIgnoreCase( " uft-8 " )))
{
response.setContentType( " text/html;charset=gb2312 " ) ; // 如果没有找定编码，编码格式设为gb2312
}

UploadForm theForm = (UploadForm) form ;
FormFile fileone = theForm.getTheFileone() ; // 取得上传的文件名

try
{
// 开始上传文件
String filePath = this .getServlet().getServletContext().getRealPath( " / " ) ; // 取得当前路径
InputStream stream = fileone.getInputStream() ; // 把文件读入
ByteArrayOutputStream baos = new ByteArrayOutputStream() ;

/*
* 建立一个上传文件的输出流如果是linux系统请把"\\" 换成 "/"
*/
OutputStream bos = new FileOutputStream(filePath + fileone.getFileName()) ;

request.setAttribute( " fileName " ,filePath + " / " + fileone.getFileName() ) ;
int bytesRead = 0 ;
byte [] buffer = new byte [ 8192 ] ;
while ( (bytesRead = stream.read(buffer, 0 , 8192 ) ) != - 1 )
{
bos.write(buffer, 0 ,bytesRead) ;
}

bos.close();
stream.close() ;

// 上传文件完成
String oldurl = filePath + fileone.getFileName() ;
String newurl = filePath + " min_ " + fileone.getFileName() ; // 新的缩略图保存地址

convertImage convert = new convertImage() ;
convert.setFileInput(oldurl) ;
convert.setFileOutput(newurl) ;
convert.convert() ;

}

catch (Exception e)
{
System.err.print(e) ;
}
return mapping.findForward( " display " );
}

}

来源:http://www.ideagrace.com/html/doc/2006/04/21/00776.html

图片上传并生成缩略图

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