IE6下保存时文件名称时文件名不一致

  <body>
  
    <a href="downloadfile.action" >下载</a>
    
  </body>
package org.jin.action ;import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.OutputStream;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionSupport;
public class uploadToolAtion extends ActionSupport{
public void downloadTool(){
HttpServletResponse response = ServletActionContext.getResponse();
HttpServletRequest request = ServletActionContext.getRequest();
try {
// application/x-msdownload   application/octet-stream  x-exe exe
response.setContentType("application/octet-stream");
// response.setHeader("Content-disposition ", "attachment;filename= "+ "chrome_installer.exe");
// String filename = "chrome_installer.exe" ;
String filepath = request.getRealPath("/")+"upload"+File.separator+"chrome_installer.exe";
File file = new File(filepath);
String filename = file.getName();
response.setHeader("Content-disposition ","attachment;filename="+new String(filename.getBytes("UTF-8"),"iso-8859-1"));
FileInputStream  input = new FileInputStream(filepath);
long filelength = filepath.length();
String downloadFileLength = String.valueOf(filelength);
response.setHeader("Content_length", downloadFileLength);
        int filelen = input.available();
        byte a[] = new byte[filelen] ;
        int len = 0 ;
        OutputStream output = response.getOutputStream();
        while ((len=input.read(a))!=-1){
         output.write(a, 0, len);
         output.flush();
         output.close();
        }
} catch (Exception e) {
}
}
}application/x-msdownload   application/octet-stream  x-exe exe
response.setContentType("application/octet-stream");
为什么我换了好几种application ，IE6下保存时文件名称时文件名称老是我链接的那个Href里面的名称呀？为什么不是这定义的chrome_installer.exe呢？真纠结！