跨网络文件上传

1:jsp
<tr>

<td colspan="2" align="left" width="75%"><s:text
name="batchfile.selectfile" />:  <input size="35%"
style="height: 20px; font-size: 12px;" type="File" name="file"
id="upload" οnkeypress="return false;" /> <input id="submit"
style="width: auto; height: 20px; height: 21px !important; font-size: 12px;"
type="submit" value="<s:text name="button.submit"/>"
οnclick="return changeBG()" /></td>

</tr>

2:js

function changeBG(){
var str = document.getElementById("upload").value;
if(str == "")
{
alert("<s:text name='batchfile.filepath.isnull'/>");
return false;
}
return checkFile();
}


function checkFile(){
var obj = document.getElementById("upload");
var str = document.getElementById("upload").value;
var fileName = str.substring(str.lastIndexOf(".")+1,str.length);
if(fileName.toLowerCase()!="txt"){
document.getElementById("upload").value="";
alert("<s:text name='batchfile.filetype.error'/>");
return false;
}
else
{
var Sys = {};
if(isFirefox=navigator.userAgent.indexOf("Firefox")>0)
{
Sys.firefox=true;
}
if(isFirefox=navigator.userAgent.indexOf("'Chrome")>0)
{
Sys.firefox=true;
}
if(isFirefox=navigator.userAgent.indexOf("'Opera")>0)
{
Sys.firefox=true;
}
if(navigator.userAgent.indexOf("MSIE")>0)
{
Sys.ie=true;
}
var filesize = 0;
var createErrorEN = document.getElementById("createErrorEN").value;
var createErrorZH = document.getElementById("createErrorZH").value;
var modifySuggest = document.getElementById("modifySuggest").value;
if(Sys.firefox)
{
filesize = obj.files[0].fileSize;
}else if(Sys.ie)
{
try
{
var filename = obj.value;
var activeObject = new ActiveXObject("Scripting.FileSystemObject");
if(!activeObject.FileExists(filename))
{
alert("<s:text name='batchfile.filepath.isnull'/>");
return false;
}
var file = activeObject.getfile(filename);
var filesize = file.size; //单位：b
}catch(e)
{
var msg = e.description;
if(msg.contains("Automation") ||msg.contains("Automatisierung"))
{
window.alert(modifySuggest);
}
else
{
window.location.reload();
}
}
}
if (parseFloat(filesize) > parseFloat(52428800))//大于50M
{
window.alert("<s:text name='batchfile.filesize.exceed'/>");
return false;
}
}
document.getElementById("hiddenFileName").value = document.getElementById("upload").value;
var all = document.getElementById("changeBG");
all.style.display = "block";
window.setTimeout("showFatherDiv()",1000);
hiddenOtherOptions();
}