Eclipse & Tomcat Example Webapp

(Free Web Tutorial)

by Michael Thomas

Tomcat Home Page

Setup Eclipse projects for the Tomcat Example webapps that get installed with Tomcat so you can edit & compile changes to existing examples.
On the Eclipse Home page, you can download the whole Eclipse site (all content, tutorials & examples) !!!

This tutorial covers: Eclipse 3.1.1 (as of 05/14/08), Apache Tomcat 6.0.16 (as of 05/25/08)

Prerequisites

• Have Eclipse installed.
• Have Tomcat installed (with Struts if you want to complete that section).
• Know how to Start/Stop Tomcat and/or Reload a WebApp  (we have a Tomcat Tutorial on that).
• This tutorials has been tested in the following environment:
  Date: 05/14/08
  OS: Win XPro
  JDK: jdk1.6.0_03

Objectives

• Create a new Eclipse project tied to existing webapps running on Tomcat that were installed with Tomcat.
• With a copy of the Tomcat examples webapp you can now make changes and experiment.

General Info

• Reload Web App or Stop/Start Tomcat Service
  • FYI - Remember if you make changes to the web.xml or .java source files you will need to "Reload" the Webapp or Start/Stop the "Apache Tomcat" service.
    (Note: There is a free Tomcat Tutorial which covers those steps.)
    • To Stop/Start the Tomcat service:
      Control Panel, Administrative Tools, Services, then right click on "Apache Tomcat" and choose Stop, then Start.
    • To reload the webapp:
      http://localhost:8080  , click "Tomcat Manager", find the webapp and choose "Reload"

examples - Tomcat's example webapp.

• Verify you have Tomcat's example webapp.
  • Using Win Explorer find the Tomcat Webapp directory.
    Possible directory:
    C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps
  • examples - this webapp exits (the directory) then you can continue this tutorial.
  • http://localhost:8080/examples - make sure Tomcat is running then verify this works!
• Create the Webapp
  • Stop Tomcat
  • Let's copy the existing web app so you can make changes without changing the original web app.
  • Go to the Tomcat webapps directory:
    Ex: C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps\
  • Make a copy of  the directory "examples" and name it:
    myeclipse-tomcat-examples
• Verify the new webapp works
  • Start Tomcat
  • http://localhost:8080/myeclipse-tomcat-examples - this should work just like the other webapp.
• Eclipse - Create a Java Project -
  • Launch Eclipse
  • File, New, Project, Java Project, Next
  • Project Name: myeclipse-tomcat-examples
  • Contents: "Create project from existing source".
  • Click "Next"
  • Click "Browse" and locate the directory in the Tomcat WebApp directory.  Click to select.
    Ex Directory:
    C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps\myeclipse-tomcat-examples
  • Folder: myeclipse-tomcat-examples
  • Click "OK"
  • Click "Next"
  • Check the box - Allow output folders for source folders.
    Note: This webapp has the .java & .class files in the same direcory.
  • On the "Java Settings" screen change the "Default output folder": myeclipse-tomcat-examples/WEB-INF/classes
    (Note: This webapp has a "plugin" directory that has .java files that do not match the scheme of the rest of the .java & .class files.  Ex directories: WEB-INF\jsp\applet & jsp\plugin\applet\examples)
  • Click "Finish"
  • WARNING READ THIS: If you see the prompt "The output folder has changed ...." click "No".
    If you click yes you will delete a needed directory.
• Eclipse - Build Path - add the Struts/Tomcat lib jars files.
  • Right click on the project.
  • Click "Build Path", "Configure Build Path", then click the tab "Libraries"
  • Check to make sure that the "JRE System Library" is listed.
    If not, click "Add Library", "JRE System Library", "Next", "Finish".
    Notes:
    Under the tab "Order and Export" this lib file should be directly under the WEB-INF/src directory.
    You can't compile .java files without this library!!!
  • Click "Add External JARs"
  • Browse to the Tomcat common library directory.
    Ex: C:\Program Files\Apache Software Foundation\Tomcat 5.5\common\lib
  • Select all of the JAR files and click "Open".
  • Click "OK" to leave the "Java Build Path" screen.
• You're finished.