Constructor in my servlet class

Can i write a constructor in my servlet class inherited from HttpServlet.
eg:
class myServlet extends HttpServlet
myServlet()
doGet(......)
}

And who will call the derived class no args constructor?
Remember Servlet classes are managed by the container which is responsible for initiating the servlets and calling appropriate life cycle methods. The container initiates the Servlet using the no args constructor. For all practical purposes you would choose the init() method rather than the constructor for initialization logic.
ram.

Similar Messages

How to reference a DatabaseHandler servlet class from a jsp file in Tomcat

Trying to create a database connection in the jsp file in webapps\project folder by referencing the DatabaseHandler class in webapps\project\WEB-INF\classes.
Here is the code in the jsp to make the connection:
DatabaseHandler db = new DatabaseHandler() ;
String sql = "SELECT password FROM cms_users WHERE user =" + userName ;
java.sql.ResultSet rs = db . selectQuery( sql ) ;
Here is the DatabaseHandler class:
import java.sql.*;
public class DatabaseHandler
     // instance variables - replace the example below with your own
private Connection connection;
     * Constructor for objects of class DatabaseHandler
     public DatabaseHandler()
String url = "jdbc:odbc:javadatabase";
// Load the driver to allow connection to the database
try
Class.forName( "sun.jdbc.odbc.JdbcOdbcDriver" );
connection = DriverManager.getConnection( url );
catch ( ClassNotFoundException cnfex )
System.err.println( "Failed to load JDBC/ODBC driver." );
cnfex.printStackTrace();
System.exit( 1 ); // terminate program
catch ( SQLException sqlex )
System.err.println( "Unable to connect" );
sqlex.printStackTrace();
public ResultSet selectQuery( String query )
Statement statement;
ResultSet resultSet = null ;
try
statement = connection.createStatement();
resultSet = statement.executeQuery( query );
catch ( SQLException sqlex )
sqlex.printStackTrace();
System . exit( 1 ) ;
return resultSet ;
Here is the error i am getting when i try to run the jsp script:
HTTP Status 500 -
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: Unable to compile class for JSP
An error occurred at line: 2 in the jsp file: /ValidateLogon.jsp
Generated servlet error:
[javac] Compiling 1 source file
C:\Program Files\Apache Group\Tomcat 4.1\work\Standalone\localhost\cms\ValidateLogon_jsp.java:47: cannot find symbol
symbol : class DatabaseHandler
location: class org.apache.jsp.ValidateLogon_jsp
DatabaseHandler db = new DatabaseHandler() ;
^

Just like in the class file you need to import any classes that you want to access in the JSP.
http://java.sun.com/products/jsp/tags/11/syntaxref11.fm7.html

Why the constructor of the base class calls first when u run the java app.

why the constructor of the base class calls first when u run the java application

For the record the other very exciting questions are:
pls give the differences between application server and web server with examples
will u pls narrate the differences between servlet context and servlet config.....
where can we find servlet config...
is there any methods to access servlet config

How can i make a servlet (class) temporarily unavailable, except for ADMIN

Hello All!
I am rather new to the programming field and have already completed a web-project in Java only with Servlets. (no jsp). I have a login procedure, means I have a user management for users and admins. If an admin is logged in, he/she should be able to deactivate the servlet with a mouse-click as long he activates it again with the same. if the servlet is deactivated, other users/admins trying to access the servlet should get a "servlet is currently unavailable" message. but the admin, who is logged in, still should be able to work with the servlet! how can i realise that?
in other words, by clicking that particular button, the servlet should be made "non-multi-thread" and other way round by activating it.
any ideas??? how can the standard "servlet currently unavailable" page be displayed? I have tomcat 4 on a linux machine! i'd be really grateful if someone oculd help me.
another question i have is, how to define a "pseudo" link address to the servlet. now, the servlet can only be accessed by typing like this: http://servername.xy.com:8080/ProjectName/servlet/ServletName (because I have activated the servlet mapping in the server.xml/web.xml with /servlet/*)
but I want a link like this: http://servername.xy.com:8080/shortname
How can I do this in an easy way?? I have treid to create a web.xml in der WEB-INF folder of the servlet with following content, but it is not working:
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>
<servlet>
<servlet-name>
shortname
</servlet-name>
<servlet-class>
ClassName
</servlet-class>
</servlet>
</web-app>
Thanks a lot in advance for your kind help,
lisa

Ok,
You'll need to find a tutorial on servlet filters. Its not that hard a concept.
http://java.sun.com/j2ee/1.4/docs/tutorial/doc/Servlets8.html#wp64572
Filters need to be configured in the web.xml.
Basically they are a buffer between a request and your servlet.
Any requests for the servlet, go through the filter first. It lets you do some processing before/after the servlet gets called. Its a good way of putting in some generic code that need to be run for many servlets - security checks are often implemented in this fashion.
This should give you an idea of the sort of thing you need. I haven't really written one before, so I copied this out of the tutorial and did some basic framework for it....
public final class TestFilter implements Filter {
   private FilterConfig filterConfig = null;
   public void init(FilterConfig filterConfig) throws ServletException {
      this.filterConfig = filterConfig;
   public void destroy() {
      this.filterConfig = null;
   public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        // if you want to get the session will need to cast request to an HttpServletRequest
        Session session = request.getSession();
        String requestURL = request.getRequestURL();
        // check if this URL is for a servlet that is disabled for this user
       // somehow you have to keep track of this ... maybe in the servletContext ?
    User user = (User) session.getAttribute("user")
      boolean disabled = checkDisabled(requestURL, user);
      // if its not disabled, go ahead
      if (!disabled)
        chain.doFilter(request, response);
    else{
        // send the servlet off somewhere else - requestDispatcher maybe?
}

Unable to load servlet class specified in the module.

Hi,
Hope that I am in the right Forum to ask this question.
I tried to develop basic servlet example as specified in http://java.sun.com/developer/onlineTraining/J2EE/Intro2/servlet/servlet.html.
When I create WAR file in Deployment tool I get the following error. How can I rectify this?
Thank you very much for any help.
Regards,
Indika
Error :
Unable to load servlet class specified in the module.
Please contact online help for assistance.
java.lang.UnsupportedClassVersionError : bonus/controller/BonusCalculationServlet (Unsupported major.minor version 49.0)

Hi Yohan_co,
I haven't used Application Server 8.2, but I think the problem is because the jdk that AS is using is previous to the jdk that your are using to compile your source files.
I hope that it helps you.
Regards

Failed to load servlet Class: org.apache.jasper.servlet.JspServlet

I am evaluating Weblogic 12c and is stuck in deployment of an application.
My application is locally developed and is working fine in Oracle Glassfish. I have install glassfish and deploy application multiple time.
In weblogic I can deploy the application successfully and the state= Prepared while Health=OK.
When I access applicaiton from web browser, it says:
Error 503--Service Unavailable
From RFC 2068 Hypertext Transfer Protocol -- HTTP/1.1:
10.5.4 503 Service Unavailable
The server.log is having messages similar to following:
When processing WebService module 'SHMA'. Failed to load servlet Class: org.apache.jasper.servlet.JspServlet
Ignoring: unable to load class:java.lang.ClassNotFoundException: org.apache.jasper.servlet.JspServlet at: weblogic.xml.schema.binding.util.ClassUtil.loadClass(ClassUtil.java:76)
Jun 4, 2013 5:59:36 PM com.sun.xml.ws.model.JavaMethodImpl freeze
WARNING: Input Action on WSDL operation RegisterOperation and @Action on its associated Web Method registerOperation did not match and will cause problems in dispatching the requests
Any idea about how to fix this??
Application is working fine in Glassfish 3.2
I am having RHEL6-3 x86 with JDK 1.6u45 for Bea Weblogic 12c.
Thanks

Probably not the right forum. But you have the honour of being the first person to ask a specific WebLogic Server question here.
The BEA dev-2-dev site still seems to be active. Try here hunting for a category here: http://forums.bea.com/index.jspa
-steve-

How to publish a servlet class to web server?

background:
web server: tomcat apache 4
context path: webapp\test\
servlet path: webapp\test\WEB-INF
servlet name: HelloWorld.class
i tried to placed the servlet class file to above servlet path,
but i can't invoke the servlet by http://localhost:8080/test/HelloWorld
what should i do in order to invoke the servlet at browser?
Is a web.xml necessary a must to provided a mapping between request name and actual class name?

First of all you need a *.war structure which look like this
/app-name
/app-name/WEB-INF/
/app-name/WEB-INF/lib
/app-name/WEB-INF/classes
When you have created this structure you add your servlet (HelloWorld.class) in the classes directory (Create the package structure first).
When this is done you need to map the servlet to a given uri which is done in the web.xml. An example is found below:
<servlet>
<servlet-name>hello</servlet-name>
<servlet-class>package.HelloWorld</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>hello</servlet-name>
<url-pattern>/hello/*</url-pattern>
</servlet-mapping>
Hopefully this will help :-)
best regards
Stig

Problem in compiling servlet class - using Tomcat

Hi,
I have a servlet pgm that I'm trying to compile.I using Tomcat application server.I have my servlet class in D:\servlet_wrk\project1\src
and my deployment descriptor in D:\servlet_wrk\project1\etc
my CLASSPATH var is set to C:\Sun\AppServer\jdk\bin
and
my PATH var is set to C:\Sun\AppServer\bin.
When I compile my servlet class Ch1Servlet.java in the command line from the directory
D:\servlet_wrk\project1 using the command
javac -classpath D:\applications\tomcat-5.5.12\common\lib\servlet-api.jar -d classes src/Ch1Servlet.java,
it says error:cannot read: src/Ch1Servlet.java
Can somebody help me to solve this problem and help me to compile my servlet class.
Thanks.

Thanks...as u said I tried putting dir & found that
my file was saved as Ch1Servlet.java.txt instead for
Ch1Servlet.java......So that was a problem.Now I'm
able to compile.Oh, yeah. Notepad will do that to you. I think when you save in Notepad if you put quotes around the name "Whatever.java" then it won't add the .txt.
But on compiling I'm getting the following error
package java.servlet.* does not exist
package java.servlet.http.* does not exist
package java.io.* does not exist
Do u the reason for this??? The servlet stuff is java[b]x.servlet. For the io stuff, I don't know, I'd have to see your code. Either you have a typo or a corrupt installation.

Servlet class path

Can anybody tell me what is the exact path to put the servlet class file in
tomcat 4. I was reading a book called more servelet by Marty Hall and its metioned there that i can put them in install_dir/webapps/ROOT/WEB-INF/classes but when i browse to WEB-INF folder there is no folder named classes there.
Please help.

firsly i installed jdk 1.3 on my computer. Then i installed tomcat 4. Then i changed port 8080 in server.xml to 80. Then i set the JAVA_HOME path to point to jdk1.3 folder. Then i setup the class path to D:\Documents and Settings\Ashi\Desktop\tomcat\apache-tomcat-4.1.34\apache-tomcat-4.1.34\common\lib\servlet.jar
Then i downloaded a source file named HelloServlet.java from author's website and compiled it. It compiled successfully. I copied the HelloServlet.class file to the classes directory that you asked me to create. Then i opened my browser and typed http://localhost/servlet/HelloServlet and getting error HTTP Status 404

Non-servlet class in servlet program

hi,
I declare a non-servlet class which is defined by myself in a servlet class. I passed the complie but got an runtime error said NoClassDefFoundError. Does anyone can help me? Thanks.
The following is my code.
//get the search string from web form
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.net.*;
import java.util.*;
public class SearchEngines extends HttpServlet {
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
String searchString = (String) request.getParameter("searchString");
     String searchType = (String) request.getParameter("searchType");
     Date date = new java.util.Date();
     response.setContentType("text/html");
PrintWriter out = response.getWriter();
Vector doc_retrieved = new Vector();
BooleanSearch bs = new BooleanSearch();
doc_retrieved=bs.beginSearch(searchString, searchType);
out.println("<HTML><HEAD><TITLE>Hello Client!</TITLE>" +
               "</HEAD><BODY>Hello Client! " + doc_retrieved.size() + " documents have been found.</BODY></HTML>");
out.close();
response.sendError(response.SC_NOT_FOUND,
"No recognized search engine specified.");
public void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
// a search engine implements the boolean search
import java.io.*;
import java.util.*;
import au.com.pharos.gdbm.GdbmFile;
import au.com.pharos.gdbm.GdbmException;
import au.com.pharos.packing.StringPacking;
import IRUtilities.Porter;
public class BooleanSearch{
     BooleanSearch(){;}
     public Vector beginSearch(String searchString, String searchType){
          Vector query_vector = queryVector(searchString);
          Vector doc_retrieved = new Vector();
          if (searchType.equals("AND"))
               doc_retrieved = andSearch(query_vector);
          else
               doc_retrieved = orSearch(query_vector);
          return doc_retrieved;
     private Vector queryVector(String query){
     Vector query_vector = new Vector();
          try{
               GdbmFile dbTerm = new GdbmFile("Term.gdbm", GdbmFile.READER);
          dbTerm.setKeyPacking(new StringPacking());
          dbTerm.setValuePacking(new StringPacking());
          query = query.toLowerCase();
          StringTokenizer st = new StringTokenizer(query);
          String word = "";
          String term_id = "";
          while (st.hasMoreTokens()){
               word = st.nextToken();
               if (!search(word)){
                    word = Stemming(word);
                    if (dbTerm.exists(word)){
               //          System.out.println(word);
                         term_id = (String) dbTerm.fetch(word);
                         query_vector.add(term_id);
          catch(GdbmException e){
               System.out.println(e.getMessage());
          return query_vector;
     private Vector orSearch(Vector query_vector){
          Vector doc_retrieved = new Vector();
          try{
               GdbmFile dbVector = new GdbmFile("Vector.gdbm", GdbmFile.READER);
               dbVector.setKeyPacking(new StringPacking());
               dbVector.setValuePacking(new StringPacking());
               int doc_num = dbVector.size();
               String doc_id = "";
               String temp = "";
               for (int i = 1; i <= doc_num; i++){
                    boolean found = false;
                    doc_id = String.valueOf(i);
                    temp = (String) dbVector.fetch(doc_id);
                    StringTokenizer st = new StringTokenizer(temp);
                    while (st.hasMoreTokens() && !found){
                         temp = st.nextToken();
                         StringTokenizer st1 = new StringTokenizer(temp, ",");
                         String term = st1.nextToken();
                         if (query_vector.contains(term)){
                              doc_retrieved.add(doc_id);
                              found = true;
          catch(GdbmException e){
               System.out.println(e.getMessage());
          return doc_retrieved;
     private Vector andSearch(Vector query_vector){
          Vector doc_retrieved = new Vector();
          try{
               GdbmFile dbVector = new GdbmFile("Vector.gdbm", GdbmFile.READER);
               dbVector.setKeyPacking(new StringPacking());
               dbVector.setValuePacking(new StringPacking());
               int doc_num = dbVector.size();
               String doc_id = "";
               String temp = "";
               for (int i = 1; i <= doc_num; i++){
                    Vector doc_vector = new Vector();
                    boolean found = true;
                    doc_id = String.valueOf(i);
                    temp = (String) dbVector.fetch(doc_id);
                    StringTokenizer st = new StringTokenizer(temp);
                    while (st.hasMoreTokens()){
                         temp = st.nextToken();
                         StringTokenizer st1 = new StringTokenizer(temp, ",");
                         String term = st1.nextToken();
                         doc_vector.add(term);
                    for (int j = 0; j < query_vector.size(); j++){
                         temp = (String) query_vector.get(j);
                         if (doc_vector.contains(temp))
                              found = found & true;
                         else
                              found = false;
                    if (found)
                         doc_retrieved.add(doc_id);
          catch(GdbmException e){
               System.out.println(e.getMessage());
          return doc_retrieved;
     private String Stemming(String str){
          Porter st = new Porter ();
          str = st.stripAffixes(str);
          return str;
     private boolean search(String str){
          //stop word list
          String [] stoplist ={"a","about","above","according","across","actually","adj","after","afterwards","again",
                                   "against","all","almost","alone","along","already","also","although","always","am","among",
                                   "amongst","an","and","another","any","anyhow","anyone","anything","anywhere","are",
                                   "aren't","around","as","at","away","be","became","because","become","becomes","becoming",
                                   "been","before","beforehand","begin","beginning","behind","being","below","beside",
                                   "besides","between","beyond","billion","both","but","by","can","cannot","can't",
                                   "caption","co","co.","could","couldn't","did","didn't","do","does","doesn't","don't",
                                   "down","during","each","eg","eight","eighty","either","else","elsewhere","end","ending",
                                   "enough","etc","even","ever","every","everyone","everything","everywhere","except",
                                   "few","fifty","first","five","for","former","formerly","forty","found","four","from",
                                   "further","had","has","hasn't","have","haven't","he","he'd","he'll","hence","her","here",
                                   "hereafter","hereby","herein","here's","hereupon","hers","he's","him","himself","his",
                                   "how","however","hundred","i'd","ie","if","i'll","i'm","in","inc.","indeed","instead",
                                   "into","is","isn't","it","its","it's","itself","i've","last","later","latter","latterly",
                                   "least","less","let","let's","like","likely","ltd","made","make","makes","many","maybe",
                                   "me","meantime","meanwhile","might","million","miss","more","moreover","most","mostly",
                                   "mr","mrs","much","must","my","myself","namely","neither","never","nevertheless","next",
                                   "nine","ninety","no","nobody","none","nonetheless","noone","nor","not","nothing","now",
                                   "nowhere","of","off","often","on","once","one","one's","only","onto","or","other","others",
                                   "otherwise","our","ours","ourselves","out","over","overall","own","per","perhaps","pm",
                                   "rather","recent","recently","same","seem","seemed","seeming","seems","seven","seventy",
                                   "several","she","she'd","she'll","she's","should","shouldn't","since","six","sixty",
                                   "so","some","somehow","someone","sometime","sometimes","somewhere","still","stop",
                                   "such","taking","ten","than","that","that'll","that's","that've","the","their","them",
                                   "themselves","then","thence","there","thereafter","thereby","there'd","therefore",
                                   "therein","there'll","there're","there's","thereupon","there've","these","they","they'd",
                                   "they'll","they're","they've","thirty","this","those","though","thousand","three","through",
                                   "throughout","thru","thus","to","together","too","toward","towards","trillion","twenty",
                                   "two","under","unless","unlike","unlikely","until","up","upon","us","used","using",
                                   "very","via","was","wasn't","we","we'd","well","we'll","were","we're","weren't","we've",
                                   "what","whatever","what'll","what's","what've","when","whence","whenever","where",
                                   "whereafter","whereas","whereby","wherein","where's","whereupon","wherever","whether",
                                   "which","while","whither","who","who'd","whoever","whole","who'll","whom","whomever",
                                   "who's","whose","why","will","with","within","without","won't","would","wouldn't",
                                   "yes","yet","you","you'd","you'll","your","you're","yours","yourself","you've"};
          int i = 0;
          int j = stoplist.length;
          int mid = 0;
          boolean found = false;
          while (i < j && !found){
               mid = (i + j)/2;
               if (str.compareTo(stoplist[mid]) == 0)
                    found = true;
               else
                    if (str.compareTo(stoplist[mid]) < 0)
                         j = mid;
                    else
                         i = mid + 1;
          return found;
     }

please show us the full error message.
it sounds like a classpath problem...

How to access an external text file in a Servlet class?

I do the regular file I/O in the Servlet class. But when I run Servlet class, text file is not loaded. Can sb tell me how to do it?
Thanx
Richard

Hi DrClap;
the following is the main servlet code, which calls other two classes.
===================================================================
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class TermsServlet extends HttpServlet {
          public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
          resp.setContentType("text/html");
          PrintWriter out = resp.getWriter();
          out.println("<HTML>");
          out.println("<TITLE>Computer Terms and Acronyms</TITLE>");
          out.println("<BODY>");
          out.println("<H1>Computer Terms and Acronyms</H1>");
          out.println("<TABLE BORDER=2>");
          out.println("<TR><TH>Term<TH>Meaning</TR>");
          TermsAccessor tax = new TermsAccessor("terms.txt");
          Iterator e = tax.iterator();
          while (e.hasNext()) {
               Term t = (Term)e.next();
               out.print("<TR><TD>");
               out.print(t.term);
               out.print("<TD>");
               out.print(t.definition);
               out.println("</TR>");
          out.println("</TABLE>");
          out.println("<HR></HR>");
          out.println("</BODY></HTML>");
=================================================
import java.io.*;
import java.util.*;
public class TermsAccessor {
     protected BufferedReader is;
     protected String ident;
     public TermsAccessor(String inputFileName) throws IOException {
          is = new BufferedReader(new FileReader(inputFileName));
          String ident = is.readLine();
     public String getIdent() {
          return ident;
     public Iterator iterator() {
     return new Iterator() {
          String line, term, defn;
public boolean hasNext() {
          try {
          return ((line = is.readLine()) != null);
          } catch (IOException e) {
          System.err.println("IO Error: " + e);
          return false;
          public Object next() {
          int i;
          while ((i = line.indexOf("\t"))<0 && hasNext());
          if (line == null)
          throw new IllegalStateException("Invalid EOF state");
                    term = line.substring(0, i);
                    defn = line.substring(i+1);
                    return new Term(term, defn);
          public void remove() {
          throw new UnsupportedOperationException();
=============================================================
public class Term {
          public String term;
          public String definition;
          public Term(String t, String d) {
          term = t;
          definition = d;
=================================================================
part of [terms.txt] file as following:
$Id: terms.txt,v 1.5 2000/03/17 04:08:55 $
AMD     American Micro Devices: a chip maker that competes with Intel.
API     Application Programmer Interface: a set of functions that a programmer can use
ASP     Active Server Pages, a Microsoft technology for imbedding certain commands in HTML pages
BSD     Berkeley Software Distribution, one of the two major flavors of UNIX. See OpenBSD
C     A computer programming language invented for writing UNIX in, and very popular in the late 1970's through the 1990's
C++     An Object-Oriented language heavily based on C; recently displaced by Java
CGI     Common Gateway Interface; a script or program used to handle a form on a web page
COBOL     COmmon Business Oriented Language, a programming language used mainly for large-scale financial applications.
CPU     Central Processing Unit, the "chip" that gives a computer its low-level personality ("machine instruction set") and performs individual instructions (add, multiply, compare...). Common CPUs include Intel/AMD "PC", SPARC, Alpha.
=================================================================
the "terms.txt" file and above class files are under the same directory. I use J2EE server to deploy the file, after run, the erro mesage is:"The requested resource (terms.txt (The system cannot find the file specified)) is not available." That means server can not locate the terms.txt file. So what file path should I use?
Thanx
Richard

Problems importing servlet classes

When I try to compile a bean which has import statements for importing servlet classes, I get the message that the class is not found in import when I compile the code. I have all these class files and I'm not sure whether I've placed them aptly. Please give me the details about placing the servlet classes and configuring my javac to import these classes.
Thanks!

If you place your classes in the %JAVA_HOME%/jre/lib/ext, they will be automatically accepted by the javac and the java. But, depending on the classes you use, it would be better to include them in %application path%/WEB-INF/lib, so they will only be used by that application.

How can I find the servlet class name from inside a ServletFilter?

Ive implemented a servlet filter, but need to discover the class name of any servlet class that gets executed.
Ive dug through the spec and cant seem to find any path to do this.
Seems the methods needed to do this have been deprecated. (for security reasons?)
Is there any way to write a ServletFilter to grab this info?
If not, is there any other way to capture every servlet execution in the container, time its execution, and log the class name along with the execution time?
(***WITHOUT*** requiring a classpath over ride of any container provider classes)
Any help is much appreciated. Been banging my head against this for some time now :(

request.getServletPath() returns the part of the URL which refers to the servlet. It isn't the classname of the servlet but it should be a reasonable surrogate. If you log that, then you could write some code which reads your web.xml and uses the servlet-mapping elements to convert it to servlet class names later.

Tomcat session expires after compiling servlet/ class

Hi,
Does anybody know why tomcat(4.1) session expires if you modify a serlvet or class and compile it.
After compiling I refresh the page and I get session invalidated page. And every time I compile I have to relogin.
Any ideas ? Is there a work around ?

In serverl.xml, if you have set the reloadable="true" attribute in your <Context/> tag for your web application then each time one of the servlet classes is modified, tomcat will reload the web application. Set reloadable="false" and this will stop.
tobes

Compiling servlet class:javac gives 'bad command'

I have a servlet class in the path: E:\Tomcat324\jakarta-tomcat-3.2.4\webapps\examples\WEB-INF\classes
I am using Tomcat 3.2.4 and Just Go (the tomcat launcher) provides this log of my settings:
CLASSPATH:
.;E:\Tomcat324\jakarta-tomcat-3.2.4\lib\servlet.jar;E:\Tomcat324\jakarta-tomcat-3.2.4\lib\ant.jar;E:\Tomcat324\jakarta-tomcat-3.2.4\lib\jaxp.jar;E:\Tomcat324\jakarta-tomcat-3.2.4\lib\crimson.jar;E:\Tomcat324\jakarta-tomcat-3.2.4\lib\webserver.jar;E:\Tomcat324\jakarta-tomcat-3.2.4\lib\jasper.jar
Executable :
E:\JBuilder35\jdk1.2.2\jre\bin\java.exe
Command line arguments (in order appended) :
-Dtomcat.home=E:\Tomcat324\jakarta-tomcat-3.2.4
org.apache.tomcat.startup.Tomcat
Environment Vars :
TOMCAT_HOME=E:\Tomcat324\jakarta-tomcat-3.2.4
TOMCAT_LIB=E:\Tomcat324\jakarta-tomcat-3.2.4\lib
JAVA_HOME=E:\JBuilder35\jdk1.2.2\jre
JAVA_EXE=E:\JBuilder35\jdk1.2.2\jre\bin\java.exe
WINDIR=C:\WINDOWS
CLASSPATH=.;E:\Tomcat324\jakarta-tomcat-3.2.4\lib\servlet.jar;E:\Tomcat324\jakarta-tomcat-3.2.4\lib\ant.jar;E:\Tomcat324\jakarta-tomcat-3.2.4\lib\jaxp.jar;E:\Tomcat324\jakarta-tomcat-3.2.4\lib\crimson.jar;E:\Tomcat324\jakarta-tomcat-3.2.4\lib\webserver.jar;E:\Tomcat324\jakarta-tomcat-3.2.4\lib\jasper.jar
In my DOS screen, I go to the path E:\Tomcat324\jakarta-tomcat-3.2.4\webapps\examples\WEB-INF\classes and type in "javac helloWorld.java" and I get the message :Bad Command or File Name
I'd greatly appreciate it if anyone could tell me what path to use in DOS to enable me to use the javac command.
My problem is there are so many paths in the Tomcat settings (above), I am not sure which one to use to compile my servlet.

Thanks for the suggestion. I am not trying to use JBuilder, just the command line from DOS so I hope that won't impact this.
JAVAC is in e:\jbuilder35\jdk1.2.2\bin
and the class that I am trying to run is in:
e:\tomcat324\jakarta-tomcat-3.2.4\webapps\examples\WEB-INF\classes
and it's called CookieExample.java
Here's a copy of my DOS Screen of what I did and the result:
E:\>set path = javac e:\jbuilder35\jdk1.2.2\bin;%path%
E:\>cd e:\tomcat324\jakarta-tomcat-3.2.4\webapps\examples\WEB-INF\classes
E:\Tomcat324\jakarta-tomcat-3.2.4\webapps\examples\WEB-INF\classes>javac CookieE
xample.java
Bad command or file name
-Any idea why I am still getting the error?

Constructor in my servlet class

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