关于Struts的下载代码报错

代码如下：Action.java
package com.yh.ccsu.Action;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;

import com.opensymphony.xwork2.ActionSupport;

public class DownloadAction extends ActionSupport {
  private String filename;

  public String getFilename() {
    return filename;
}

public void setFilename(String filename) {
    this.filename = filename;
}

//输入流方法
public InputStream getInputStream() throws FileNotFoundException{

    FileInputStream fis = new FileInputStream("D:/FileTest"+filename);
    return fis;
}
@Override
public String execute() throws Exception {
    // TODO Auto-generated method stub
    System.out.println("下载中...");
    return SUCCESS;
    }
}

Struts.xml

Download.jsp

点击链接就会报错：
找了一天了没找到解决办法，不知道哪里写错了。

http://zhidao.baidu.com/link?url=tdDHB1HxMCfyOF3Cx8w7EE4d7hk4v4WB9LRpO67ZVicqS54WrXHoDq_krb_CyFaY6YHnwl7tWF63FRzXiWO0ra

 
attachment;filename="${fileName}" 

的attachment和后面的分号去掉