简单文件下载

前台ext调用方法  随便的一个方法名

onDeclare : function() {
		
		window.open(this.MftDeclHeadAction + this.delcareReplenishManifest+"&manifestId="+this.mftDeclHeadForm.getForm().findField("manifestId").getValue());
}

this.MftDeclHeadAction + this.delcareReplenishManifest action 组成访问路径
action层

public ActionForward sendReplenishDoc(ActionMapping mapping, ActionForm form,HttpServletRequest request, HttpServletResponse response)throws Exception {
		if (request.getParameter("manifestId") != null) {
			String mftId = (String)request.getParameter("manifestId");
	      try {
		      StringBuffer documentBuffer = this.mftDeclManager.getReplenishDoc(mftId);
				response.setContentType("application/x-download");  
			    response.setHeader("content-disposition", "attachment;filename=" + java.net.URLEncoder.encode(mftId+".xml", "UTF-8"));
					byte[] bytes = documentBuffer.toString().getBytes("UTF-8");
				     BufferedInputStream bis = new BufferedInputStream(new ByteArrayInputStream(bytes));
				     OutputStream out = new BufferedOutputStream(response.getOutputStream());
				     int i=-1;
						while ((i = bis.read()) != -1) {
							out.write(i);
						}
						out.close();
						bis.close();
			}catch(Exception e){
				e.printStackTrace();
			}
			
		}
		return mapping.findForward("");
	}

documentBuffer只是返回要下载的文件内容