Java Help - tomcat servlet

Author

tomcat servlet

Hai Tran

2004-03-29, 10:36 am

I have browse through some of the posted notes on Tomcat Servlet and
couldn't find a fix. I am very new at this and any help is
appreciated.

I have installed MYQL and Tomcat 4.1 on WinXP. Manage to get the
Tomcat up and was able to view my app (myapp). Had my myapp in the
following directory:

c:/tomcat/webapps/myapp/WEB-INF/classes/ - contains all the java class
programs.

Web.xml contains:

<?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>topper</servlet-name>
<servlet-class>testme</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>topper</servlet-name>
<url-pattern>/servlet/*</url-pattern>
</servlet-mapping>
</web-app>

Created two simple hello java programs called "testme" and "abc123"
and put them under the "classes" directory. Had my URL pointer to
"http://localhost:7500/myapp/servlet/testme" which work for testme.
When I changed the URL to test the second program
("http://localhost:7500/myapp/servlet/abc123"), abc123, I only get
testme? Is there a way to set Tomcat so Tomcat will execute the any
classes from the URL?

1. Isn't servlet-name is just any name you give assign??
2. Servlet-class is the a test class program locate in the classes
directory so Tomcat knows where to look for all others???
3. url-pattern is the specify the URL pattern to expected return???

I am so confuse ...

Bryce (Work)

2004-03-29, 1:56 pm

On 29 Mar 2004 06:39:45 -0800, Hai.Tran@qwest.com (Hai Tran) wrote:

>Web.xml contains:
>
><?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>topper</servlet-name>
> <servlet-class>testme</servlet-class>
> </servlet>
> <servlet-mapping>
> <servlet-name>topper</servlet-name>
> <url-pattern>/servlet/*</url-pattern>
> </servlet-mapping>
></web-app>

ok, nothing wrong with this, as long as:

1. the class (full class name, including any packages) is testme.class
2. Any URL with the pattern http://yourserver/servlet/* will be
directted to your server.

>Created two simple hello java programs called "testme" and "abc123"
>and put them under the "classes" directory. Had my URL pointer to
>"http://localhost:7500/myapp/servlet/testme" which work for testme.
>When I changed the URL to test the second program
>("http://localhost:7500/myapp/servlet/abc123"), abc123, I only get
>testme? Is there a way to set Tomcat so Tomcat will execute the any
>classes from the URL?

Yes, because that's what you specified above.

You need 2 servlet declarations, such as:

<web-app>
<servlet>
<servlet-name>testme</servlet-name>
<servlet-class>testme</servlet-class>
</servlet>
<servlet>
<servlet-name>abc123</servlet-name>
<servlet-class>abc123</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>testme</servlet-name>
<url-pattern>/servlet/testme</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>abc123</servlet-name>
<url-pattern>/servlet/abc123</url-pattern>
</servlet-mapping>
</web-app>

>1. Isn't servlet-name is just any name you give assign??

Yes, servlet-name is a reference to a servlet. You use that same name
in servlet-mapping, etc.

>2. Servlet-class is the a test class program locate in the classes
>directory so Tomcat knows where to look for all others???

No. servlet-class is the class name of the servlet.

>3. url-pattern is the specify the URL pattern to expected return???

No. url-pattern is the URL that is used by the servlet container
(Tomcat) to know when to call your servlet.

>I am so confuse ...

I'd suggest finding some servlet tutorials.

--
now with more cowbell

Hai Tran

2004-03-30, 5:50 pm

Bryce - Thank you so much for your help and clarification. To sum from
what you have said. I have to declare every servlet programs that will
be called in the web.xml file? Isn't there a dynamic or better way
other then declaring each servlet to be call?

Also, I've did purchase a book called "JSP, Servlets, and MYSQL by
David Harms" but it briefly mention it. Do you have other book
suggestion?

"Bryce (Work)" <spamtrap@berzerker-soft.com> wrote in message news:<63ng60prkjfnkslrmsmt8sf61cc89jk013@4ax.com>...
> On 29 Mar 2004 06:39:45 -0800, Hai.Tran@qwest.com (Hai Tran) wrote:
>
>
>
> ok, nothing wrong with this, as long as:
>
> 1. the class (full class name, including any packages) is testme.class
> 2. Any URL with the pattern http://yourserver/servlet/* will be
> directted to your server.
>
>
> Yes, because that's what you specified above.
>
> You need 2 servlet declarations, such as:
>
> <web-app>
> <servlet>
> <servlet-name>testme</servlet-name>
> <servlet-class>testme</servlet-class>
> </servlet>
> <servlet>
> <servlet-name>abc123</servlet-name>
> <servlet-class>abc123</servlet-class>
> </servlet>
> <servlet-mapping>
> <servlet-name>testme</servlet-name>
> <url-pattern>/servlet/testme</url-pattern>
> </servlet-mapping>
> <servlet-mapping>
> <servlet-name>abc123</servlet-name>
> <url-pattern>/servlet/abc123</url-pattern>
> </servlet-mapping>
> </web-app>
>
>
> Yes, servlet-name is a reference to a servlet. You use that same name
> in servlet-mapping, etc.
>
>
> No. servlet-class is the class name of the servlet.
>
>
> No. url-pattern is the URL that is used by the servlet container
> (Tomcat) to know when to call your servlet.
>
>
> I'd suggest finding some servlet tutorials.

Bryce (Work)

2004-03-31, 9:51 am

On 30 Mar 2004 13:54:19 -0800, Hai.Tran@qwest.com (Hai Tran) wrote:

>Bryce - Thank you so much for your help and clarification. To sum from
>what you have said. I have to declare every servlet programs that will
>be called in the web.xml file? Isn't there a dynamic or better way
>other then declaring each servlet to be call?

Yes, each servlet must be declared in the web.xml file (as far as I
know). No, there is no dynamic way.

>Also, I've did purchase a book called "JSP, Servlets, and MYSQL by
>David Harms" but it briefly mention it. Do you have other book
>suggestion?

I don't know that book. I use the O'Reilly book "Java Servlet
Programming".

--
now with more cowbell

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