If you split expression to more lines, debugging
of following lines is shifted.

Create new JSP and put following code to it:

==================================

<%= "first line" +
    "second line" +
    "third line"%>

<%! private String mymethod() {
       return "mymethod";
    } %>
<%-- put breakpoint here --%>   
<% out.println(mymethod()); 
   int i = 10;
   i = 20;
%>
    

<%= i++ %>

<%= i++ %>


==================================

Put breakpoint to marked line and start debugger. 
Add variable i to watches.
Trace JSP by pressing F7. 
Note that you will jump to mymethod() 2 lines down
than it should be. Also variable i is changed late.