如何将信息从servlet传递到JSP页面

Question

Is it possible to have a servlet that contains an object (an ArrayList in this case) that then does the equivalent of displaying a jsp page and passing that object to the jsp page. In this case the ArrayList contains database results an I want to iterate through and display the results on the JSP page.

I am not using any MVC framework, is it possible to do this with the basic Servlet/JSP architecture.

Answer 1

Yes.

1. in the servlet call request.setAttribute("result", yourArrayList);

2. then forward to the jsp:

    getServletContext().getRequestDispatcher("your.jsp") .forward(request, response); 

3. using JSTL, in the jsp:

    <c:forEach items="${result}" var="item"> ... </c:forEach> 

If you don't want to use JSTL (but I recommend using it), then you can get the value using request.getAttribute("result") in the JSP as well.

Alternatively, but not recommended, you can use request.getSession().setAttribute(..) instead, if you want to redirect() rather than forward() .

Answer 2

You can pass objects to jsp's by embedding them within the Request.

request.setAttribute("object", object);

and within the jsp:

request.getAttribute("object");

Answer 3

You can put it using request.setAttribute("myobj", myObj); see javadoc

Answer 4

If you are trying to make some kind of "component" then it's better to convert the JSP page into a custom tag. Here is excellent article about that: http://onjava.com/pub/a/onjava/2004/05/12/jsp2part4.html