Doing various DB calls in one servlet

Hi,
I have a Servlet that deletes a User from the Database.Before deleting the User the servlet needs to delete other dependencies in cascade, that is deleting,updating...etc on other tables.The question is How should I proceed? Should I do different methods that take the connection to the database,do their work and close it or take the connetion in the servlet service method and send it as a parameter for the methods.
Thanks in advance.

For performance reason and for integrity reason, you should use the same connection for all your sql orders, because :
- opening connectino takes time
- having all orders ina connection allow you to rollback the all transaction if a problem occurs
St�phane

Similar Messages

Calling One Servlet From Another

Thanks in advance for any advice!
I would like to call servletB from servletA then use the response returned from servletB within the processing of servletA.
I have checked the forums and jGuru but nothing I've found really matches the problem. RequestDispatcher has "forward" and "include" but I do not want to include the reponse from the called servlet in the response of the original one.
Here is the situation. I have a web application that uses an applet front-end using a mainframe datasource. The applet displays data in various JTables and prints various reports.
The applet calls a servlet(B) with an SQL statement in the request that responds with a Vector of data to be displayed in the JTable. This is working fine.
The applet also calls servlet(A) which uses iText from SourceForge to create a PDF report that is sent back to the browser for display in Adobe Reader. This also works fine.
Because I cannot figure out how to call servletB from within servletA, my current workaround is to embed the code of servletB inside servletA. Not very good OOP and as the application grows maintaining this will become a problem.
Any suggestions would be greatly appreciated.
Max

Why don't you just take the code that the applet uses to "call" servlet B and replicate that code into servlet "A"? (Or better still, create a class to do that, which could be called both from the applet and from servlet A.)

Calling one Servlet from another servlet

          First servlet...............>
          package javaservlets.samples;
          import javax.servlet.*;
          import javax.servlet.http.*;
          public class TableElements extends HttpServlet{
               public void doGet(HttpServletRequest request,HttpServletResponse response)
               throws ServletException,IOException{
                    response.setContentType("text/plain");
                    try{
                         RequestDispatcher rd = getServletContext().getRequestDispatcher("/TableFilter");
                         if(request==null){
                              System.out.println("Request null...");
                              System.exit(0);
                         if(response == null){
                              System.out.println("Response null...");
                              System.exit(0);
                         if(request!=null&&response != null){
                         System.out.println("Both are not null...");
                         rd.forward(request,response);
                    }catch(ServletException se){
                         se.printStackTrace();
                    }catch(IOException ioe){
                         ioe.printStackTrace();
          Second Servlet..............>
          package javaservlets.samples;
          import javax.servlet.*;
          import javax.servlet.http.*;
          public class TableFilters extends HttpServlet{
               public void service(HttpServletRequest request,HttpServletResponse response)
               throws IOException,ServletException{
                    String type = request.getContentType();
                    System.out.println("type : "+type);
          from the TableElement servlet just I am calling the TableFilter servlet and in
          the TableFilter I am trying to print the request content type. But I am getting
          NULL. i was supposed to get "TEXT/PLAIN".
          can any one tell what is the problem.
          very urgent.
          thanx in advance


Your example seems to assume that the reponse of the first servlet becomes
          the request in the second servlet let this is not so. After the forward the
          request and response obejcts are the same as before the forward, except the
          referer attribute is changed.
          "Gururaj Kosigi" <[email protected]> wrote in message
          news:[email protected]...
          >
          > First servlet...............>
          >
          > package javaservlets.samples;
          >
          > import javax.servlet.*;
          > import javax.servlet.http.*;
          >
          >
          > public class TableElements extends HttpServlet{
          >
          >
          >
          > public void doGet(HttpServletRequest request,HttpServletResponse response)
          > throws ServletException,IOException{
          >
          > response.setContentType("text/plain");
          >
          >
          > try{
          >
          > RequestDispatcher rd =
          getServletContext().getRequestDispatcher("/TableFilter");
          >
          > if(request==null){
          > System.out.println("Request null...");
          > System.exit(0);
          > }
          > if(response == null){
          > System.out.println("Response null...");
          > System.exit(0);
          > }
          > if(request!=null&&response != null){
          > System.out.println("Both are not null...");
          > }
          >
          > rd.forward(request,response);
          > }catch(ServletException se){
          > se.printStackTrace();
          >
          > }catch(IOException ioe){
          > ioe.printStackTrace();
          >
          > }
          >
          > }
          > }
          >
          > Second Servlet..............>
          >
          > package javaservlets.samples;
          >
          > import javax.servlet.*;
          > import javax.servlet.http.*;
          >
          >
          > public class TableFilters extends HttpServlet{
          >
          > public void service(HttpServletRequest request,HttpServletResponse
          response)
          > throws IOException,ServletException{
          >
          >
          > String type = request.getContentType();
          > System.out.println("type : "+type);
          >
          > }
          > }
          >
          > from the TableElement servlet just I am calling the TableFilter servlet
          and in
          > the TableFilter I am trying to print the request content type. But I am
          getting
          > NULL. i was supposed to get "TEXT/PLAIN".
          >
          > can any one tell what is the problem.
          > very urgent.
          >
          > thanx in advance

Issue while making a AJAX call to a servlet in ALUI.

Hi,
The problem scenario is :
I log into the portal using "http://147.149.132.93:7001/portal/server.pt"
i have two instances of applications which have same files but provide different functionality one on 147.149.132.93 and other on 147.149.132.102 .
I have configured my portlet that points to the application on 147.149.132.102 , when i make a ajax call to a servlet using the relative path for the aaplication , in normal scenario the ajax should make call to the servlert on the 147.149.132.102 but this does not happen and ajax makes call to the servlet on the machine 147.149.132.93 .
Is there any issue regarding usage of Ajax in ALUI portal?
Why the Ajax takes the server path from the portal login URL and not from the remote server configured for the portlet ? ?:|
HELP !!!!!!!!!!!!!!!
Regards,
Prashant

I m also facing same problem. I resolve the problem by simply giving >complete servlet address in ajax call.There are 2 issue with this:
1) AJAX call will bypass portal, so it makes calls unsafe + you can not use portal functionality anymore. Plus some other issue like session expiration and so on.
2) URL is hardcoded, so it's difficult to manage.
All calls (include ajax) have to go through portal in portal environment. It means that AJAX url has to be gatewayed like any other url. There is no issue with ajax in portal. In G6 make sure that <inline> refresh checkbox (for WS) is unchecked.
Here is example how to create AJAX URL on the fly by using Javascript. Let's say we have 2 files in root folder of <RemoteProjectName> web application:portlet.jsp file and ajaxExample.jsp.
Code in portlet.jsp may looks like
<script>
var Url = "<pt:url xmlns:pt='http://www.plumtree.com/xmlschemas/ptui/' pt:href='ajaxExample.jsp'/>";
</script>
Here is what you can get as result of this transformation (based on data provided in first post):
http://147.149.132.93:7001/portal/server.pt/gateway/PTARGS_0_0_XXX_XXX_X_XX/http%3B/147.149.132.102%3B/RemoteProjectName/ajaxExample.jsp
where XXX - are numbers specific to particular portal environment.
Edited by Bryazgin at 12/21/2007 7:43 AM

Require client cert for just one servlet

Hello
I enabled SSL with mutual authentication in tomcat 5.5.x into Jboss like this:
<Connector port="443" address="${jboss.bind.address}"
maxThreads="100" strategy="ms" maxHttpHeaderSize="8192"
emptySessionPath="true"
scheme="https" secure="true" clientAuth="true"
truststoreFile="${jboss.server.home.dir}/conf/confiaveis.truststore"
truststorePass="111111"
keystoreFile="${jboss.server.home.dir}/conf/.keystore"
keystorePass="111111"
sslProtocol = "TLS" />
It�s working perfectly and any servlet requires client certificate. But now, i would like that just one servlet require client cert.
Does any body could help me ?

Application and web servers base their authentication mode on Listeners and not Servlets. Since Listeners listen on ports, and and can direct client calls to any number of Servlets, all Servlets served by a Listener will default to the authentication mode of the Listener.
If you want to have selective authentication based on Servlets, then you should use a non-ClientAuth port for most of your Servlets, and redirect the client request to port 443 for the one Sevlet that needs ClientAuth. As a result, you will get the same effect.

3 responses in one Servlet?

Hi
I have a problem with mixig diffrent respones in one servlet. I use "text/plain" , "image/gif "and "text/html" in one servlet. the problem is that only the first ande the last response is showing not the image. I would like the image to show for a couple seconds. Is this possible? I have tried the Thread.sleep() but it didn�t help. I�m using a package from oreilly. Submitting my code below
Thanks.
public void doGet(HttpServletRequest req, HttpServletResponse res) throws IOException, ServletException {
   // res.setContentType("text/plain");
    //PrintWriter out = res.getWriter();
   ServletOutputStream out=res.getOutputStream();
   MultipartResponse mr=new MultipartResponse(res);
   Date day=new Date();
   out.println("Day and time is: ");
   String pattern="yyyy-MM-dd HH:mm:ss";
   //Create a newt SimpleDateobject using the pattern above
   SimpleDateFormat fo=new SimpleDateFormat(pattern);
   String de =fo.format(day);
//text respons
     for(int i=10; i>0; i--){
      mr.startResponse("text/plain");
      out.println("Dat :");
      out.println(de);
      out.println(i+"!!");
      mr.endResponse();
     try
           Thread.sleep(1000);
        }catch(InterruptedException ine){}
      //bild respons
       mr.startResponse("image/gif");
      try
         ServletUtils.returnFile(req.getRealPath(LAUNCH), out);
      }catch(FileNotFoundException e){
            out.println("File not found");
      try{
      Thread.sleep(4000);
      }catch(InterruptedException i){
      mr.endResponse();
      //text/html respons
      mr.startResponse("text/html");
      out.println("<BR> It works</BR>");
      mr.endResponse();
      mr.finish();
}

Hmm, sorry, there sort of is a way with multipart
responses. However, check out the
com.oreilly.servlet.MultipartResponse documentation:
<i>Note that Microsoft Internet Explorer does not
understand this sort of response.</i>
So applicable only for browsers that happen to
support that hack / extension.Thanks for your reply !
Now it works, it turned out that all I had to do was to call Thread.sleep() in the last response to.

Calling 3 different servlets from a single servlet

hi all,
i am in lot of soup...i am new to servlets,etc....so help me pls.
i need to call 3 different servlets from one servlet. all 3 servlets that i want to call perform different functions and execute queries on the database.
what i am trying to do is:
there is an html page that call a servlet called authenticate.java.(whose code is at the bottom of this page).
the servlet authenticate.java should authenticate a user according to the password and username supplied in the html page.
MAINLY:-
i need to display 3 buttons to the authenticted user. those 3 buttons each should call 3 different servlets, which do different things.
now in authenticte.java i set certain information in the session using session.putValue();
further, whatever servlet is called, i need to use that information i set into the session...using session.getValue().
PLS TELL ME HOW TO DO THAT...ALSO C IF THE BELOW CODE IS OK.
ALSO TELL ME HOW TO END A SESSION. ALSO DO SERVLETS SUPPORT SESSIONS?
I AM USING jdk1.3 and jsdk2.0.
* Authenticate.java
// this places all user variables in session
//to access use session.getAttribute
//dispatcher stuff
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpServlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import java.sql.*;
import java.io.*;
import java.util.*;
* @author Gudiya
* @version
public class Authenticate extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, java.io.IOException {
HttpSession session = request.getSession(true);
Connection con=null;
String sessionid;
String deptcode;
String desig;
String add1;
String add2;
String contname;
PrintWriter out = response.getWriter();
try
{System.out.println(1);
response.setContentType("text/html");
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
con=DriverManager.getConnection("jdbc:odbc:SACFA","","");
System.out.println("connection established");
catch(ClassNotFoundException e){
System.out.println("database driver not found");
System.out.println(e.toString());
catch(Exception e){System.out.println(e.toString());
String username=request.getParameter("username");
String password=request.getParameter("password");
try{
System.out.println(2);
PreparedStatement stmt=con.prepareStatement("SELECT * FROM AUTHENTICATION,mb_add where AUTHENTICATION.NAME=? AND AUTHENTICATION.PASSWORD=? AND mb_add.DEPT_NAME=?");
stmt.setString(1,username);
stmt.setString(2,password);
stmt.setString(3,username);
ResultSet rs=stmt.executeQuery();
System.out.println(3);
boolean rowfound=false;
rowfound=rs.next();
if (rowfound==true)
sessionid=session.getId();
System.out.println(sessionid);
System.out.println(4);
session.putValue("user",username);
rs.beforeFirst();
while (rs.next())
System.out.println(5);
deptcode=rs.getString("DEPT_CODE");
desig=rs.getString("DESIGNATION");
add1=rs.getString("ADDRESS1");
add2=rs.getString("ADDRESS2");
contname=rs.getString("NAME");
session.putValue("dept_code",deptcode);
session.putValue("designation",desig);
session.putValue("address1",add1);
session.putValue("address2",add2);
session.putValue("cont_name",contname);
System.out.println(6);
}          out.println("<html>");
          out.println("<head>");
          out.println("<title>Successful Login Screen</title>");
          out.println("</head>");
          out.println("<body bgcolor='ORANGE'>");
out.println("WELCOME SACFA MEMBERS FROM "+ username);
//print decorative html statements here
          out.println(" SELECT ANY ONE ACTION:-");
//out.println("<form Action="+"\"servlet/noc\""+" method =post>");//call for your noc servlet
//print decorative html statements here
out.println("<INPUT TYPE=submit VALUE='GENERATE NOC' NAME='NOC'>");
out.println("</form>");
//print decorative html statements here
//out.println("<form Action="+"\"servlet/comments\""+" method =post>");//call for your comment servlet
out.println("<INPUT TYPE=submit VALUE='ENTER/ MODIFY COMMENTS' NAME='COMMENTS' >");
out.println("</form>");
//print decorative html statements here
// out.println("<form Action="+"\"servlet/bye\""+" method = post>");
out.println("<INPUT TYPE=submit VALUE=EXIT NAME=EXIT >"); //place javascript fucction for exiting window
out.println("</form>");
          out.println("</body>");
          out.println("</html>");
con.close();
} catch( SQLException e){ }
out.close();}
THANK YOU,
REGARDS,
ASHNA

Hi Ashna,
You have use three different forms for three buttons. But I think all are commented one.It will also work if you uncomment it.
Else you can use only one Form without giving action in form tag. Use normal buttons instead of submit type buttons & call different JavaScript functions on onClick event for each button.
Try this out.
Ajay

What's the best way to transfer (not forward) a call from one iPhone to another?

What's the best way to transfer (not forward) a call from one iPhone to another? Is there an app available that does this? I'm asking about receiving a call, then transferring that caller to another iPhone on a separate number and then disconnecting while those two users are joined up in a conversation.

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Just to close the loop on this (and for the next person trying to figure out how to do it), I was able to [extend X509KeyManager as described in Alexandre Saudate's blog|http://alesaudate.com/2010/08/09/how-to-dynamically-select-a-certificate-alias-when-invoking-web-services/] . I was then able to set the com.sun.xml.ws.developer.JAXWSProperties.SSL_SOCKET_FACTORY on my JAX-WS request context to use my custom SSLSocketFactory, and it works like a charm!
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Why does my phone call go directly to voice mail when I call my daughter? No others do this.

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Message was edited by: EVELYN ESKRIDGE

cowboy
Clarifications... when you say "... only some calls..." and "... someone says they called..." - are these all from from one caller?
After following all these fine suggestions and eliminating them systematically, consider that this kind of stuff is as old as the cellphone system. A few possibilities that occur to me just regarding the network system:
you are in a habitually dead spot area. I have one in my own house!
you travel through many of these dead zones (traditionally called 'low-coverage' areas) - remember how big a deal the coverage maps were to us?
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CCC

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XIRWBUSER doing lot of calls with SXMS_ALERT_ERROR_RECEIVE

Hi
I have noticed that our XI System Jlaunch process is using log of CPU (some times 100%). Even after adding extra processor the problems remains same.
On investigation, I have noticed that XIRWBUSER doing lot of call with SXMS_ALERT_ERROR_RECEIVE.
i have found note 913858 which describes our problem (see below):
Quote:
Q4: Why are there so many RFC calls of the user XIRWBUSER calling SXMS_ALERT_ERROR_RECEIVE as can be seen in the ST03N "Workload Monitor" and the "RFC Server Profile"?
A4: This happens usually on development or test systems where lots of sender adapter channels are inadvertently misconfigured (e.g. missing sender agreement, wrong logon parameters etc.). Use the Adapter Monitor of the Runtime Workbench to identify these channels and deactivate them.
Unquote:
Any idea on how to deactivate them?
Also, any other ideas on why Jlaunch process is using lot of CPU. It looks like it's using available CPU, but it is releasing when it is required by other process. Is it normal?
Regards
Chandu

dude, you got one thing right: you don't know about me. My first 3-4 support request were polite and I was asking 1 or 2 thing. I got no answer at all (not within 48 hours not within a month). You're saying they are annoyed with me **bleep** can I say when I spent money on this phone and I got **bleep** in return. So why don't you just keep your smart**bleep** comments to yourself, if you can't answer my questions. Thank you with sugar on top, do not reply to this post, bye!

Doing various DB calls in one servlet

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