Re: how do i test ?

From:
"gk" <srcjnu@gmail.com>
Newsgroups:
comp.lang.java.programmer
Date:
8 Oct 2006 02:20:43 -0700
Message-ID:
<1160299243.689402.143080@m7g2000cwm.googlegroups.com>
Manish Pandit wrote:

Hi,

You will never notice the difference at the browser level.


but i am getting browser level difference !!

 The

difference is in the generated servlet code of your JSP.


Yes

ok...here i have three files which i did experiment but still not
clear about the concept.

here are the jsp files.

A.jsp
======
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>

<%

int x = 2;

out.println("hai");

%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>

</body>
</html>

B.jsp
======
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>

    <%int x=3;

    out.println(x);

    %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<include file="A.jsp"><%out.println(x);%>

</body>
</html>

C.jsp
======
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<%int x=3;

    out.println(x);

    %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<jsp:include page="A.jsp" />
</body>
</html>

then , i tried to open in browser

but i found the output as following ...

in I.E:

B.jsp===>outputs 3 3

C.jsp===> 3 hai

 >In case of the

directive, the included code goes in the calling JSP before it is
translated into a class file.


what do you mean by this ?

well, i am copying the generated code under _jspService method for
the directive

B_jsp.java
-----------------

public void _jspService(HttpServletRequest request, HttpServletResponse
response)
        throws java.io.IOException, ServletException {

    JspFactory _jspxFactory = null;
    PageContext pageContext = null;
    HttpSession session = null;
    ServletContext application = null;
    ServletConfig config = null;
    JspWriter out = null;
    Object page = this;
    JspWriter _jspx_out = null;
    PageContext _jspx_page_context = null;

    try {
      _jspxFactory = JspFactory.getDefaultFactory();
      response.setContentType("text/html; charset=ISO-8859-1");
      pageContext = _jspxFactory.getPageContext(this, request,
response,
       null, true, 8192, true);
      _jspx_page_context = pageContext;
      application = pageContext.getServletContext();
      config = pageContext.getServletConfig();
      session = pageContext.getSession();
      out = pageContext.getOut();
      _jspx_out = out;

      out.write("\r\n");
      out.write(" \r\n");
      out.write(" ");
int x=3;
    out.println(x);

      out.write("\n");
      out.write("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01
Transitional//EN\">\n");
      out.write("<html>\n");
      out.write("<head>\n");
      out.write("<meta http-equiv=\"Content-Type\" content=\"text/html;
charset=ISO-8859-1\">\n");
      out.write("<title>Insert title here</title>\n");
      out.write("</head>\n");
      out.write("<body>\n");
      out.write("<include file=\"A.jsp\">");
out.println(x);
      out.write("\r\n");
      out.write("</body>\n");
      out.write("</html>");
    } catch (Throwable t) {
      if (!(t instanceof SkipPageException)){
        out = _jspx_out;
        if (out != null && out.getBufferSize() != 0)
          out.clearBuffer();
        if (_jspx_page_context != null)
_jspx_page_context.handlePageException(t);
      }
    } finally {
      if (_jspxFactory != null)
_jspxFactory.releasePageContext(_jspx_page_context);
    }

 In case of jsp:include, the code that

goes into the servlet is like a *runtime* link.


link ? what link.....yea...i found something like below in the
generated code

org.apache.jasper.runtime.JspRuntimeLibrary.include(request, response,
"A.jsp", out, false);

is that you meant ?

here is the full _jspService method for this....

C_jsp.java
----------------
  public void _jspService(HttpServletRequest request,
HttpServletResponse response)
        throws java.io.IOException, ServletException {

    JspFactory _jspxFactory = null;
    PageContext pageContext = null;
    HttpSession session = null;
    ServletContext application = null;
    ServletConfig config = null;
    JspWriter out = null;
    Object page = this;
    JspWriter _jspx_out = null;
    PageContext _jspx_page_context = null;

    try {
      _jspxFactory = JspFactory.getDefaultFactory();
      response.setContentType("text/html; charset=ISO-8859-1");
      pageContext = _jspxFactory.getPageContext(this, request,
response,
       null, true, 8192, true);
      _jspx_page_context = pageContext;
      application = pageContext.getServletContext();
      config = pageContext.getServletConfig();
      session = pageContext.getSession();
      out = pageContext.getOut();
      _jspx_out = out;

      out.write('\n');
int x=3;
    out.println(x);

      out.write("\r\n");
      out.write("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01
Transitional//EN\">\n");
      out.write("<html>\n");
      out.write("<head>\n");
      out.write("<meta http-equiv=\"Content-Type\" content=\"text/html;
charset=ISO-8859-1\">\n");
      out.write("<title>Insert title here</title>\n");
      out.write("</head>\n");
      out.write("<body>\n");
      org.apache.jasper.runtime.JspRuntimeLibrary.include(request,
response, "A.jsp", out, false);
      out.write("\n");
      out.write("</body>\n");
      out.write("</html>");
    } catch (Throwable t) {
      if (!(t instanceof SkipPageException)){
        out = _jspx_out;
        if (out != null && out.getBufferSize() != 0)
          out.clearBuffer();
        if (_jspx_page_context != null)
_jspx_page_context.handlePageException(t);
      }
    } finally {
      if (_jspxFactory != null)
_jspxFactory.releasePageContext(_jspx_page_context);
    }

 So, if you remove the

incuded JSP after the servlet is generated, in case of directive, it
will work fine,


what do you mean by this........its not at all including the jsp file
at all....because you see the print above ..............so there is no
meaning of removing it !

but in case of <jsp:include> it will fail as the
servlet will not be able to find the JSP.


thats true.

Take a peek at the _jspService() method of the generated servlets for
both cases - you will be able to figure it out right away.


yea.....i have posted it.

in the case of include:file , its not all including the file at all
!!!

and hence i could not verify your comment also .

confused now

-cheers,
Manish


thanks

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