java 返回到在 Servlet 中使用 RequestDispatcher 发送请求的同一个 JSP
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Go back to same JSP that sent request with RequestDispatcher in Servlet
提问by Colinch
I have a servlet which can get requests by multiple JSP's.
我有一个 servlet，它可以通过多个 JSP 获取请求。
But when I use the RequestDispatcher in the servlet, I don't know how to forward to the JSP that sent the request.
但是当我在servlet中使用RequestDispatcher时，我不知道如何转发到发送请求的JSP。
req.getRequestDispatcher("page.jsp").forward(req, resp);
I know there is something like this in html: javascript:javascript:history.go(-1)
我知道 html 中有这样的东西：javascript:javascript:history.go(-1)
I just need something like this:
我只需要这样的东西：
req.setAttribute("originalRequest", req.getRequestPage());
req.getRequestDispatcher(originalRequest).forward(req, resp);
That piece of code is probably very noob but it gives you the idea of what I need.
这段代码可能非常菜鸟，但它让您知道我需要什么。
So: I need to forward to the page that sent the original request (basically reload the page), but because multiple jsp's use the servlet, I cannot simply forward to "page.jsp"
所以：我需要转发到发送原始请求的页面（基本上重新加载页面），但是因为多个jsp使用servlet，我不能简单地转发到“page.jsp”
回答by Prasad Kharkar
You can do following
您可以执行以下操作
- Create a hidden parameter for every jsp named
jspNameand give value for respective JSPs. e.g. for JSP A, parameter name isjspNameand value isa, for JSP B, parameter name isjspNameand value isb Read this hidden parameter in the servlet using following code.
String jspName = request.getParameter("jspName"); RequestDispatcher rd = request.getRequestDispatcher(jspName); rd.forward(request, response);
- 为每个命名的 jsp 创建一个隐藏参数，
jspName并为相应的 JSP 提供值。例如对于 JSP A，参数名称是jspName，值是a，对于 JSP B，参数名称是jspName，值是b 使用以下代码读取 servlet 中的这个隐藏参数。
String jspName = request.getParameter("jspName"); RequestDispatcher rd = request.getRequestDispatcher(jspName); rd.forward(request, response);
When you are calling the servlet from JSP A, then it will have paramter japName=a, when servlet code is running, it will retrieve the value afrom request.getParamter("jspName")and a getRequestDispatcher(jspName)will create the dispatcher for the same and rd.forward(request, response)will forward to the jsp.
当您从 JSP A 调用 servlet 时，它将具有 paramter japName=a，当 servlet 代码运行时，它将a从中检索值request.getParamter("jspName")，agetRequestDispatcher(jspName)将为其创建调度程序rd.forward(request, response)并将转发到 jsp。
回答by SM ANSARI
I have not tried the following, but I hope this may help you to solve your problem.
我还没有尝试过以下方法，但我希望这可以帮助您解决问题。
req.setAttribute("originalRequest", req.getRequestPage());
req.getRequestDispatcher(req.getAttribute(originalRequest).toString()).forward(req, resp);
