如果你曾用VB编写文件上传的组件的话，那么用JAVA编写文件上传的JAVABEAN十分容易。
下面的例子只是一个简版
package yuanyifileup;
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.jsp.PageContext;

public class yuanyifileup
{
private ServletRequest request;
private ServletResponse response;
private ServletConfig config;
ServletInputStream DATA;
int FormSize;
File f1;
FileOutputStream os;
DataInputStream is;
String filename;
byte[] b;
byte t;
boolean flag=false;
public yuanyifileup()
{ }
public void initialize(ServletConfig config,HttpServletRequest request,HttpServletResponse response) throws IOException
{
this.request=request;
this.response=response;
this.config=config;
DATA = request.getInputStream();
FormSize=request.getContentLength();
}
public void initialize(PageContext pageContext) throws IOException
{
request=pageContext.getRequest();
response=pageContext.getResponse();
config=pageContext.getServletConfig();
DATA = request.getInputStream();
FormSize=request.getContentLength();
}
public boolean setFilename(String s)
{
try
{
File f1=new File(s);
os=new FileOutputStream(f1);
}
catch(IOException e)
{return(false);}
return(true);
}
public void getByte()
{
int i=0;
try
{
is=new DataInputStream(DATA);
b=new byte[FormSize];

while (true)
{
try
{
t=is.readByte();
b[i]=t;
i++;
}
catch(EOFException e)
{ break;}
}
is.close();}
catch(IOException e)
{}
}

public boolean save()
{
int i=0,start1=0,start2=0;
String temp="";
if (!flag)
{
getByte();
flag=true;
}
try
{
temp=new String(b,"ISO8859_1");
}
catch(UnsupportedEncodingException e)
{return(false);}

start1=temp.indexOf("image/");
temp=temp.substring(start1);

start1=temp.indexOf(" ");

temp=temp.substring(start1+4);
start2=temp.indexOf("; ");
if (start2!=-1)
{
temp=temp.substring(0,start2);
}
try
{
byte[] img=temp.getBytes("ISO8859_1");
for (i=0;i<img.length;i++)
{ os.write(img[i]); }
os.close();
}
catch(IOException e)
{return(false);}

return(true);

}

}