用ActiveXObject可实现从客户端本地上传文件到服务器端的功能

1、javascript代码如下，filePath为服务器路径：

function sendFileToServer(filePath){

　　  var stream =newActiveXObject("ADODB.Stream");

　　  stream.Type=1; 

    stream.Open(); 

    stream.Position = 0;

    stream.LoadFromFile(filePath) //可以读取服务器端文件,并下载到本地指定路径

    stream.Position = 0;

    sendByteStreamToServer(stream,appRoot+"/uploadServlet?cmd=upload&filePath="+filePath);

　　  stream.Close();

}

//辅助JS函数：将服务器端文件下载到客户端本地

var dbfdata;

function sendByteStreamToServer(stream,url){

if (window.XMLHttpRequest) {

   xmlhttp = newXMLHttpRequest();

   if(xmlhttp.overrideMimeType) {

      xmlhttp.overrideMimeType("text/xml")

   }

} else if (window.ActiveXObject) {

   var activexName =["MSXML2.XMLHTTP","Microsoft.XMLHTTP"];

   for (var i = 0; i< activexName.length; i++) {

      try {

          xmlhttp =new ActiveXObject(activexName[i]);

         break;

      } catch(e) {

         e.print();

      }

   }

}

xmlhttp.onreadystatechange = callback_upload;

xmlhttp.open("post", url, false);

boundary="abcd"

xmlhttp.setRequestHeader("Content-Type", "multipart/form-data,boundary="+boundary);

   xmlhttp.setRequestHeader("Content-Length", stream.Size);

xmlhttp.send(stream);

}

//得到数据

function callback_upload() {

if (xmlhttp.readyState == 4) {

    if (xmlhttp.status ==200) {

       var responseText = xmlhttp.responseText;

       dbfdata =responseText;

    } else

    {

       alert("系统错误");

    }

}

}

2、JAVA后台代码：把文件读到本地

String cmd = request.getParameter("cmd");

OutputStream ou = (OutputStream)response.getOutputStream();

if ("upload".equalsIgnoreCase(cmd)) {

String filePath = newString(request.getParameter("filePath").getBytes("iso8859-1"),"GBK");

String fileName =filePath.substring(filePath.lastIndexOf("\\") + 1);

String loadPath =Constant.ROOTPATH  +"upload_files" +                   System.getProperties().getProperty("file.separator"); //上传文件存放目录

InputStream in = request.getInputStream();

BufferedInputStream bis = new BufferedInputStream(in);

StringtempPath=(String)request.getSession().getAttribute("tempPath");

if(tempPath==null||tempPath.equalsIgnoreCase("")){

tempPath=UUID.randomUUID().toString();

request.getSession().setAttribute("tempPath", tempPath);

}

loadPath=loadPath+tempPath+System.getProperties().getProperty("file.separator");

File newFile = new File(loadPath);

if (!newFile.exists())

newFile.mkdirs();

BufferedOutputStream bos = new BufferedOutputStream(newFileOutputStream(new File(loadPath + fileName.toLowerCase())));//获得文件输出流

int b = 0;

while ((b = bis.read()) != -1) {

bos.write(b);

}

in.close();

bis.close();

bos.close();

ou.write(tempPath.getBytes());

ou.close();