Hi all,
It's not clear to me how PageContext can be used. If I understand well it has a very limited scope, that is if I move from one jsp to another what I store in the page context gets lost...........can it be used only for intermediate processing page data? (like Controllers)
Thanks
Francesco

The PageContext object is implicity defined as 'pageContext' in JSP and JSP tag libraries. Usually, pageContext is useful for storing and retrieving objects by string name (like a hashmap) within a single JSP, accessible within a JSP and any tag library it uses. For example, I have a database connection tag (only to find out one already existed on http://jakarta.apache.org) that creates a connection and stores it in pageContext making it accessible to my other tag libraries.

For example:

<mytag:connection id="con" dataSourceRef="mydsn" />

In my tag library code, I store the connection in pageContext mapped to the id string:

public void setId(String id) {
    this.id = id;
}

public void setDataSourceRef(String dataSourceRef) {
    this.dataSourceRef = dataSourceRef;
}

public int doStartTag() throws JspException {
    try {
        // getting connection from data source
        Context ctx = new InitialContext();
        DataSource ds = (DataSource) ctx.lookup(this.dataSourceRef);
        Connection con = ds.getConnection();
        
        // storing connection in pageContext
        pageContext.setAttribute(this.id, con);

    } catch (Exception ex) {
        // err sorry lazy right now =p
    }
}


Now I can access the connection in the JSP:

<%
  Connection con = (Connection)pageContext.getAttribute("con");
%>

Or in another taglib in the same JSP:

<mytag:closeConnection id="con" />


There are also ways to define the scope of the pageContext object (i.e. request, session, application), but I usually use the implicit HttpServletRequest, HttpSession, and ServletContext objects (request, session, application =p).
I suggest you read the servlet API doc for more information.

Hope this helps!