如何通过超链接从JSP将对象发送到Servlet？

Question

How can I send a an object got it from a bean in a JSP page to a Servlet after clicking an hyperlink??

something like...

...
<td align="center"><% if(j.getClubActual().isIsResource()){ request.setAttribute("equipo", j.getClubActual());%>
<a href="teamServlet" type="submit" target="_blank"><%= j.getClubActual().getNombre()%></a><%}%>
</td>
...

But when I try to recover it in the teamServlet, the request object is empty.

Thanks in advance.

Answer 1

What object you are trying to send?

If you want to "send" objects, I think your safest bet is to use HTTP session to do that. You can't send "objects" (or beans) with a hyperlink to a servlet. You can only send parameters values usually in form of strings.

Answer 2

The lifetime of a HTTP request ends when its associated HTTP response is finished sending the data (read: the HTML page generated by JSP). Clicking a link will create a brand new HTTP request which doesn't contain the attributes of any previous request at all.

You need to send the unique identifier of the Java object in question as a request parameter. Ultimately, the HTML must end up to basically look like this:

<a href="teamServlet?clubId=123">link</a>

In the servlet, you can get the request parameter as follows:

String clubId = request.getParameter("clubId");

You can use this value to re-obtain the Java object associated with the given ID from some data store.

Club club = clubService.find(Long.valueOf(clubId));
// ...