Servlet-HTML connection

I'm having some problems connecting html to a servlet. Im currently at my university and under my own root, the servlet is under /booksonline/html/servlet. the html code looks like this
<tr>
<FORM ACTION="http://localhost:8080/BooksOnline/HTML/servlet.MyServlet" METHOD=POST>
<td valign="center"><B>Login Name: </B></td>
<td valign="center"><input type="text" name="LoginName" size="50" maxlength="50" value=""></td>
</tr>
and the corresponding part in MyServlet looks like this:
public void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException
String name=req.getParameterValues("LoginName")[0];
//*****Construct a response in HTML*****
String reply="<HTML>\n<HEAD><TITLE>Sample response</TITLE></HEAD>\n<BODY>\n<CENTER><BR><B>\n";
reply=reply.concat("hi "+ name);
reply=reply.concat("\n</B></CENTER>\n</BODY>\n</HTML>");
//*****Send the reply*****
res.setContentType("text/html");
PrintWriter out=res.getWriter();
out.println(reply);
out.close();
i think the servlet should be fine as it was taken from an online tutorial. i think the problem may lie in it not being able to find it.
i have also tried combinations such as
="http://localhost:8080/BooksOnline/HTML/servlet/MyServlet", MyServlet.class and so on and so forth. Its really basic at the moment, but once i have it running, then i can actually have it doing better stuff. Can anyone help?!
cheers
Alex Thomas

Hi,
do i have to be running tomcat at this point? at the moment im just trying to get some connectivity before using tomcat. I just want to see that i can actually connect the html with the java. is this possible without using tomcat?
cheers
alex

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I made the following changes as suggested, to the LoginHandlaer code.
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out.print("Rec: "+buf);

Hi,
Since you use POST Method for the request, you have to implement the doPost(...) Method in the servlet, right? Do a simple implementation of the doGet(...) Method and call the Servlet using a browser. So you can easily check, whether the Servlet is available or not. You got the Error 404 which means, that the Servlet cant be found on the Tomcat. Make sure, that it is deployed correctly and your URL in the MIDlet is also correct.
hth
Kay

Servlet - database connection usage

Hi
I am writing a servlet based upon the multi thread model (default in many cases).In the servlet, I go to database 2 or 3 times per request and get data. I have broken down my main method into 4 methods. so method 1 calls method 2 with some params, method 2 calls method 3 etc.
I am using connection pooling. I am passing the connection object from method 1 to downstream methods. and release the connection only at the end.
My question is since this servlet can be accessed by multiple threads, is this a good practice of passing connection downstream since a servlet might try to access with a closed connection object. Should I just get connection objects from the pool and release them inside each method.
thanks

Hi
I am writing a servlet based upon the multi thread
model (default in many cases).In the servlet, I go to
database 2 or 3 times per request and get data. I have
broken down my main method into 4 methods. so method 1
calls method 2 with some params, method 2 calls method
3 etc.
I am using connection pooling. I am passing the
connection object from method 1 to downstream methods.
and release the connection only at the end.
My question is since this servlet can be accessed by
multiple threads, is this a good practice of passing
connection downstream since a servlet might try to
access with a closed connection object. Should I just
get connection objects from the pool and release them
inside each method.
thanksIf the Connection is a local variable for the service, doPost, doGet, etc... there isn't any problem with your aproach.
If it is, then your Connection is shared between all the threads that run concurrently (run througth the servlet).
Concerning your aproach (and the Connection beeing a local variable), there is no problem in passing it to the next method by parameter because it is the same thread running the code.
MSB

Save servlet html output as jpeg.

Hello everybody,
I have a servlet that creates an html page.
The html consits of information from a database and displays a data sheet with images and text.
I have been asked if the outputed data sheet can be saved as an image (jpeg).
Is this possible?
Thanks.

I am can of confused how this works
I know that there is more to do in order to create an
image.First you have to make a desition, what do you need?
* if you only want to save a data sheet i think the better solution is a Excel format file, for this yo coul take a look at http://jakarta.apache.org/poi/hssf/index.html
* if you want to generate a pdf with images, tables, etc. yo should take a look at http://xml.apache.org/fop/
* if you want to create a custom image i cant help you
the proces to generate excel isnt dificult but to make a pdf is a little hard. but if you read the documentation and the examples you shouldnt have problems
Jorge

Servlet-html

How to send values from servlet to html..
I retrieve values from database using servlet pgm and want to display in textfield...
do reply
thx,
dish

You welcome to use my code... the syntax is not 100% for i changed table names, field names, etc for copyright purposes... but this is how i did mine
You will need to change it according to yur program/output
Create your SQL statement ...
=======================================================================================================
String q8="SELECT *     + "from search_projects "
     + "where queried_user_name = '" + g_user_name + "'";
os.println("<BR><BR><BR>");
DisplayQuery(q8, res, "view");
========================================================================================================
static String DisplayQuery(String p_sql,HttpServletResponse res, String p_heading_types)
throws ServletException,IOException
PrintWriter os=res.getWriter();
Statement stmt = null;
String l_error = "";
try
stmt = con.createStatement();
stmt.execute(p_sql);
ResultSet rs = stmt.getResultSet();
if (rs != null)
DispResultSet(rs, res, p_heading_types);
rs.close();
return(p_sql);
catch (Exception e)
os.println("<BR><BR>EXCEPTION. Unable to execute. If problem persists, please contact");
os.println(e);
return("<BR>ERROR3");
===================================================================================================
static void DispResultSet(ResultSet rs, HttpServletResponse res, String p_heading_types)
throws ServletException,IOException, SQLException
PrintWriter os=res.getWriter();
ResultSetMetaData rsmd = rs.getMetaData ();
int p=0;
int numCols = rsmd.getColumnCount ();
if (p_heading_types.equals("view"))
while (rs.next())
os.println("<TABLE BORDER=1 COLS=" + numCols + ">");
     os.println("<TR>");
     os.println("<TD>");
os.println("<TH><FONT color=blue>Id</FONT></TH>");
os.println("</TD>");
     os.println("<TD>");
os.print("<FONT color=black>"+rs.getString(1)+"</FONT></TD>");
     os.println("</TD>");
     os.println("</TR>");
     os.println("<TR>");
     os.println("<TD>");
os.println("<TH><FONT color=blue>Amount</FONT></TH>");
     os.println("</TD>");
     os.println("<TD>");
os.print("<FONT color=black>"+rs.getString(2)+"</FONT></TD>");
     os.println("</TD>");
     os.println("</TR>");
     os.println("<TR>");
     os.println("<TD>");
os.println("<TH><FONT color=blue>rings</FONT></TH>");
     os.println("</TD>");
     os.println("<TD>");
os.print("<FONT color=black>"+rs.getString(3)+"</FONT></TD>");
     os.println("</TD>");
     os.println("</TR>");
     os.println("<TR>");
     os.println("<TD>");
os.println("<TH><FONT color=blue>Date</FONT></TH>");
     os.println("</TD>");
     os.println("<TD>");
os.print("<FONT color=black>"+rs.getString(4)+"</FONT></TD>");
     os.println("</TD>");
     os.println("</TR>");
     os.println("<TR>");
     os.println("<TD>");
os.println("<TH><FONT color=blue>Email</FONT></TH>");
     os.println("</TD>");
     os.println("<TD>");
os.print("<FONT color=black>"+rs.getString(5)+"</FONT></TD>");
     os.println("</TD>");
     os.println("</TR>");
os.println("</TABLE>");
os.println("<BR><BR><BR>");
p=p+1;
Thanks
Naren

Java Servlet/Html link problem

Hi,
I have been using the Java servlet to create the html code itself using the PrintWriter.I would like to know if it possible to input ALL the code into -
PrintWriter out=null;
out.println("<Html><Body>the entrie html code</Body></Html>");
or must I input in this form?-
out.println("<html>");
out.println("<Body>");
out.println("<The entire html code>");
out.println("</Body>");
out.println("</Html>");
Does it really make a difference?
I would also like to know it is possible to retrive data from a database and (via servlet) input the list of data into the combo-box of an html Webpage.
Thank you very much for your assistance.Kindly acknowledge receipt.
Yours sincerely,
Aeshan
PS- I'll send more information soon

Your answers are yes ...and yes.
But don't use:
PrintWriter out=null;
Use:
PrintWriter out = response.getWriter();
Usually the println() method is used to make both the servlet source code ...as well as the html it generates ...a little nicer to read. This may or may not be important to you, but may matter to your employer and those who maintain your code in the future.

Declarative security of servlet- html view changes depending upon the role ??

          Hi All,
          There is acl for ejb methods and we can restrict roles to use certain
          methods of the bean. Now my question is that
          Is something possible in a declarative fashion so that user can have
          certain options enabled and certain disabled in the jsp/servlet output
          depending upon his role ?
          For example, let suppose we have a servlet MyServlet that creates an
          html output with some input boxes and buttons (add, modify, delete). Now
          is it possible, that ceratin user will only see modify button, some
          won't see any button, can only view the screen depending upon their role
          and verything in declarative fashion ?
          Any suggestion is welcome.
          TIA,
          Sudarson


Servlet security is defined in the context of the web application containing
          the servlet, and web app security provides for the declarative protection of
          resources like servlets, jsps and html pages; so the answer is no.
          See http://e-docs.bea.com/wls/docs61///webapp/security.html
          Thanks
          Jim
          sudarson wrote:
          > Hi All,
          >
          > There is acl for ejb methods and we can restrict roles to use certain
          > methods of the bean. Now my question is that
          >
          > Is something possible in a declarative fashion so that user can have
          > certain options enabled and certain disabled in the jsp/servlet output
          > depending upon his role ?
          >
          > For example, let suppose we have a servlet MyServlet that creates an
          > html output with some input boxes and buttons (add, modify, delete). Now
          > is it possible, that ceratin user will only see modify button, some
          > won't see any button, can only view the screen depending upon their role
          > and verything in declarative fashion ?
          >
          > Any suggestion is welcome.
          >
          > TIA,
          > Sudarson
          [Reply.vcf]

Servlet-HTML connection

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