看了好多网上用struts1.x实现文件下载功能的介绍了
action的写法大致有三 1， 用输入流，输出流
2， 用dispatcher
3， 用downloadAction
可是，怎么没看见个下载完成后跳转到成功画面的写法呢
用了第一和第二两种写法，最后都只能return null,如果写成return mapping.findForward("success"),则都会因为response已经提交而报exception
莫非都是下载完了就什么也不管了？
很疑惑，不知道怎么办好？有解决方法么，或者非正规的解决方法也好
[b]问题补充：[/b]
这段代码也是我从论坛上看来的，下载没有问题，画面forward不可
[code="java"]
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) {
FileDownLoadForm fdform =(FileDownLoadForm)form;
String path = fdform.getFilePath();
BufferedInputStream bis = null;
BufferedOutputStream bos = null;
InputStream fis = null;
OutputStream fos = null;
try{
File uploadFile = new File(path);
fis = new FileInputStream(uploadFile);
bis = new BufferedInputStream(fis);
fos = response.getOutputStream();
bos = new BufferedOutputStream(fos);
response.reset();
response.setHeader("Content-disposition", "attachment;filename =" + URLEncoder.encode(path, "utf-8"));
int bytesRead = 0;
byte[] buffer = new byte[4096];
while((bytesRead = bis.read(buffer,0,4096)) != -1){
bos.write(buffer, 0, bytesRead);
}
bos.flush();
fis.close();
bis.close();
fos.close();
bos.close();
//return mapping.findForward("success");
return null;
} catch(Exception e){
e.printStackTrace();
System.out.println(path);
ActionMessages downErrors = new ActionMessages();
ActionMessage downError = new ActionMessage("errors.download", path);
downErrors.add(ActionMessages.GLOBAL_MESSAGE, downError);
saveMessages(request, downErrors);
return mapping.findForward("error");
}
}
[/code]
[b]问题补充：[/b]
对应第二种方法的
也是从论坛看来的
[code="java"]
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) {
FileDownLoadForm fdform =(FileDownLoadForm)form;
String path = fdform.getFilePath();
response.setContentType("application/x-download");
String filenamedownload = path;
String filenamedisplay = path.substring(path.lastIndexOf("/")+1);
try {
filenamedisplay = URLEncoder.encode(filenamedisplay,"UTF-8");
response.addHeader("Content-Disposition","attachment;filename=" + filenamedisplay);
RequestDispatcher dispatcher = request.getRequestDispatcher(filenamedownload);
if(dispatcher != null)
{
dispatcher.forward(request,response);
}
response.flushBuffer();
return null ;
// return mapping.findForward("success");
}
catch(Exception e) {
e.printStackTrace();
ActionMessages downErrors = new ActionMessages();
ActionMessage downError = new ActionMessage("errors.download", path);
downErrors.add(ActionMessages.GLOBAL_MESSAGE, downError);
saveMessages(request, downErrors);
return mapping.findForward("error");
}
}
[/code]
可以分两步，第一步处理下载之前的事务，第二步利用弹出窗口做下载。在弹出窗口上面做文章控制父页面的消息显示。
想直接一个请求做是不行的，因为response已经返回了的缘故。
如果跳转最后的页面不复杂，你可以直接在action里输出吧。。。上传文件直接用jsp就可以了，不用那么复杂
检查一下你的文件下载请求响应的顺序吧，action不会有什么问题的．
由于线性提交时间长
会看像假死一样.......
一般用ajax来作....成功页面
叫作异步....
建议用AJAX来检测用户下载，这样的界面比较友好，而且，最后只需要返回一个字符串或XML就可以了，很方便，而且，很友好