Tomcat Installation

1
Tomcat Installation
2
Installation Guide

• Download the apache zip from Blackboard (or the
  apache web site)
• Unzip to convenient location, may be best if not
  inside your normal java workspace.
• Set environment variables. Go to Control Panel
  and select System. Then Advanced tab, then the
  Environment Variables button. In the CTLM, right
  click on My Computer and select Properties.
• Add these variables for your user
• JAVA_HOME location of your jdk, e.g.,
  c\jdk1.5.0. In the CTLM this is under
  C\Program Files\Java, which must be entered as
  c\Progra1\Java because of the spaces
• TOMCAT_HOME not sure if this is still needed,
  but it should point to location of Tomcat
  installation, e.g.,
• c\apache-tomcat-6.0.10
• Copy the mysql-connector jar to
  apache-tomcat-6.0.10\lib
• Copy and unzip advjhtp1.zip file from Blackboard
• Place in the webapps directory under
  apache-tomcat-6.0.10
• In Eclipse, create new project from existing
  source (so files remain in webapps directory but
  you can edit within Eclipse). Select
  advjhtp1\WEB-INF\classes.
• Add servlet.jar as an external jar in the Build
  Path for your project.

3
Running your program

• To start Tomcat
• cd into apache-Tomcat-6.0.10\bin
• startup
• NOTE on your home computer you can install
  Tomcat as a windows service
• To run a servlet, you must connect via Tomcat
  (you cant just open the file in the browser).
• In your browser, type the URL http//localhost80
  80/advjhtp1/servlets/WelcomeServlet.html
• To run the servlet without the html page, in your
  browser type http//localhost8080/advjhtp1/welco
  me1?
• When youre done
• cd into apache-Tomcat-6.0.10\bin
• shutdown

4
Making Changes

• If you make a change to a source file, you must
  shutdown and restart Tomcat. You can avoid this
  by making the following change to content.xml (in
  conf directory)
• ltContext reloadable "true"gt
• If you make a change to an html file you can
  simply refresh the page.

5
WEB-INF\web.xml

• web.xml file containing a deployment descriptor
  (configuration file for web app)
• must be in WEB-INF directory
• lt!DOCTYPE web-app PUBLIC "-//Sun Microsystems,
  Inc.//DTD Web Application 2.2//EN"   
  "http//java.sun.com/j2ee/dtds/web-app_2_2.dtd"gt
  ltweb-appgt  lt!-- General description of the Web
  Application --gt  ltdisplay-namegt    Advanced
  Java How to Program JSP and Servlet Chapter
  Examples  lt/display-namegt  ltdescriptiongt  
   This is the Web application in which
  we demonstrate our JSP and Servlet examples.  
  lt/descriptiongt  ltservletgt    ltservlet-namegtwelc
  ome1lt/servlet-namegt      ltdescriptiongt      A
  simple servlet that handles an HTTP get request.
       lt/descriptiongt    ltservlet-classgt     
  com.deitel.advjhtp1.servlets.WelcomeServlet  
   lt/servlet-classgt  lt/servletgt 
  ltservlet-mappinggt     ltservlet-namegtwelcome1lt/ser
  vlet-namegt    lturl-patterngt/welcome1lt/url-pattern
  gt  lt/servlet-mappinggtlt/web-appgt

6
web.xml cont

• Options for specifying URL patttern
• Can specify server http//localhost8080/advjhtp1
  /welcome1
• If server not specified, assumed to be the same
  as the server/port from which browser downloaded
  the Web page.
• Can use a path mapping, which begins with / and
  ends with /, and indicates that any URL path
  that matches the pattern will be sent to the
  servlet, for example /advjhtp1/example/
• Can use an extension mapping, which indicates
  that any request for a file with the specified
  extension will be sent to the servlet that
  handles those files, such as .jsp would send the
  request to the servlet that handles JSP requests.
  
• The default servlet is specified as /, similar to
  default document of Web server (e.g., enter
  www.deitel.com into browser, receive default
  document index.html).

7
Deploying a web app

• Set up the directory structure under webapps, for
  example advjhtp1
• advjhtp1 web app name/context root
• advjhtp1\servlets contains .html files
• advjhtp1\WEB-INF deployed application, includes
  web.xml
• advjhtp1\WEB-INF\classes root for your java
  servlet classes, also servlet.jar (unless you
  have set a path for servlet.jar)

8
Deploying, cont

• Web applications are often deployed in Web
  application archive (WAR) files, not covered in
  this text

9
More details

• localhost is a well-known server host name on
  most computers that support TCP/IP-based
  networking protocols such as HTTP.
• Allows users without a network connection to see
  networking programs on the local computer.
• 8080 is the TCP port at which Tomcat awaits
  requests. Web browsers assume TCP port 80.
• Ports are logical locations, not physical
  hardware ports.  May also be called handshake
  point.  If the client does not specify the port,
  the service won't be found.  Ports are positive
  integers up to 65,535.  Below 1024 is usually
  reserved for system services (e.g., email, www). 
  Well-known port number describes popular services
  on the Internet, such as port 80 for Web
  servers. 
• Tomcat is run alone for this chapter, but it
  could be integrated with a Web server such as
  Apache HTTP Server or Microsoft's IIS.
• Some web servers support servlets directly,
  normally via a special installation procedure. 
• When a servlet changes, Tomcat must be restarted
  (unless have hot load)