JSF 文件下载

													<h:commandLink actionListener="#{referenceGuideCtrller.download}" value="Download" >
														<f:param name="fileLink" value="#{refFile.filePath}"></f:param>
													</h:commandLink>

 

    public void download() {    
    	try {      
    		FacesContext fc = FacesContext.getCurrentInstance();
    		String fileName = FacesContextUtil.getRequest().getParameter("fileLink");
    		String filePath = FacesContextUtil.getFileUploadPath() + fileName;
    		logger.debug("file path:" + filePath);					//filePath:/mnt/vishuo-data/reference/test.txt      
    		ByteArrayOutputStream baos= downloadFile(filePath);      
    		HttpServletResponse response = (HttpServletResponse) fc.getExternalContext().getResponse();      
    		response.reset(); 
    		response.setHeader("Content-disposition", "attachment; filename=" + fileName.substring(fileName.lastIndexOf("/")+1)); //不是内嵌显示(attachment)，而是作为附件下载   
//	    	response.setHeader("Content-disposition", "inline; filename=" + fileName.substring(fileName.lastIndexOf("/")+1)); //内嵌显示(inline)   
    		response.setContentType("application/x-download");
    		response.setContentLength(baos.size()); 
    		ServletOutputStream sos = response.getOutputStream();      
    		baos.writeTo(sos);      
    		baos.close();      
    		sos.flush();  
    		sos.close();
    		FacesContext.getCurrentInstance().responseComplete();
    	} catch (IOException ex) { 
    		logger.debug(ex);    
    	}    
    }
    
    public ByteArrayOutputStream downloadFile(String fileName) throws IOException {    
    	FileInputStream fis=new FileInputStream(fileName);    
    	BufferedInputStream bis=new BufferedInputStream(fis);    
    	ByteArrayOutputStream baos=new ByteArrayOutputStream();    
    	BufferedOutputStream bos=new BufferedOutputStream(baos);        
    	int i;    
    	while((i=bis.read())!=-1) {      
    		bos.write(i);   
    	}    
    	bos.flush();  
    	bis.close();    
    	return baos;  
    }