Java Struts2下载文件

html：

<form  name="deleteUserForm" method="post" enctype="multipart/form-data">
///////////
</form>
<button id="download">下载</button>

$().ready(function(){
  $("#download")
	.button()
	.click(
		function(){
			deleteUserForm.action = "downloadFile.action";
			deleteUserForm.submit(); 
		}
	);		
});

struts.xml

<action name="downloadFile" class="userAction" method="downloadFile">  
   <result name="success" type="stream">  
       <param name="contentDisposition">   
          attachment;filename="${fileName}"  
      </param> 
      <param name="inputName">downloadFileStream</param>   
   </result>   
</action> 

UserAction

private String fileName;
public String getFileName() {
	SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-DD");
	String fileName = sf.format(new Date()).toString() + ".xls";
	try {
		fileName = new String(fileName.getBytes(),"utf-8");
	} catch (Exception e) {
		e.printStackTrace();
	}
	return fileName;
}
public void setFileName(String fileName) {
	this.fileName = fileName;
}

public String downloadFile(){
	return SUCCESS;
}
public InputStream getDownloadFileStream(){
	String directory = "/upload";
	String targetDirectory = ServletActionContext.getServletContext().getRealPath(directory);
	try {
		return new FileInputStream(new File(targetDirectory, uploadFileFileName));
	} catch (FileNotFoundException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
	return null;
}

struts.xml 中fileName 对应 action中fileName， downloadStream对应action中 getDownloadStream， get方法首字母小写。

根据路径+文件名，返回文件流。

fileName可直接根据时间设置，也可以根据目录列出文件名获取。

fileList = getfiles(getdbName);  
  
public  String getfiles(String dbDir){  
//       String t=Thread.currentThread().getContextClassLoader().getResource("").getPath();   
//       System.out.println(t);  
//          if(t.indexOf("WEB-INF")>0)  
//              t = t.substring(1,t.indexOf("/WEB-INF/classes"));  
    String t ="C:/DB_Backup";  
    if(dbDir != null && !dbDir.equals("")){  
            t +="/"+dbDir;                
    }  
    String  str = readFile(t);   
    return str;          
}  
public String readFile(String fileName) {   
       String output = "";   
       File file = new File(fileName);   
                 
       if(file.exists()){   
           if(file.isFile()){   
               try{   
                   BufferedReader input = new BufferedReader (new FileReader(file));   
                   StringBuffer buffer = new StringBuffer();   
                   String text;   
                   while((text = input.readLine()) != null)   
                   buffer.append(text +"\n");   
                   output = buffer.toString();                       
            } catch(IOException ioException){   
                  System.err.println("File Error!");   
            }   
        } else if(file.isDirectory()){   
            String[] dir = file.list();   
            //     output += "Directory contents:\n";   
                      
           for(int i=0; i<dir.length; i++){   
                 output += dir[i] +",";   
           }   
        }   
    } else{   
          System.err.println("Does not exist!");   
    }   
    return output;   
}