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[[Category:Index]][[Category:CISC 322]]
In [http://www.cs.queensu.ca/~cisc322 CISC 322], we will use the Eclipse programming environment to create Java and JSP programs, and the Winstone servlet container to run them. This page provides instructions for how to set up your first JSP project with Eclipse and Winstone.

== Installation ==
Eclipse and Winstone are installed for your use in the [http://www.caslab.queensu.ca/ CASLab]. If you wish to install Eclipse and Winstone at home, follow [[Installing Eclipse and Winstone at Home|these instructions]].

== Locating Your Files ==
Assuming you are developing an application called ''Example'' and that your deployment directory is called ''webapps'', you should structure your directory like this:
* <tt>workspace</tt>
** <tt>Example</tt>
*** <tt>src</tt>
**** application's ''*.java'' files
*** <tt>ROOT</tt>
**** application's ''*.jsp'' and ''*.html'' files
**** <tt>WEB-INF</tt>
***** <tt>classes</tt>
****** application's ''*.class'' files
***** <tt>lib</tt>
****** applications ''*.jar'' files

You will use ''Eclipse'' to develop your application's class files, and ''Winstone'' as your servlet container to allow execution of your application from a web browser.

== Running Eclipse ==
In the CASLab, run Eclipse via '''Start|Programs|Program Development|Eclipse|Eclipse 3.3.0'''. Make sure to use this version of Eclipse. Eclipse will prompt you where to save your workspace. The default is on your Z: drive. This is a good choice, as it will allow you to use Eclipse from any CASLab computer.

At home, run Eclipse via the shortcut you created when installing. Place your repository whereever you wish.

If this is your first time using Eclipse, I recommend that you follow the '''Tutorials''' link on the Eclipse ''Welcome'' screen (shown as a chalkboard icon), and work through the ''Build a simple Java application'' tutorial.

== Creating a JSP Project Under Eclipse ==
You will use Eclipse to create the class files used by your web application. You can also use Eclipse to edit your JSP files.

=== Creating a JSP Project ===
* In Eclipse, click the '''File''' menu and select '''New|Java Project'''.

* A dialogue will appear with the header ''Create a Java Project''.
** In the '''Project Name''' field, enter this project's name. We will assume that the project is called ''Example''.
** Under ''Project Layout'', ensure that ''Create separate source and output folders'' is selected.
** Click '''Next'''.

* The dialogue header will change to ''Java Settings''.
** Under ''Default Output Folder'', fill in '''Example/ROOT/WEB-INF/classes'''. Note that the spelling is very important here.
** Click '''Finish''' to create the new project.

=== Testing the JSP Project ===
You can test that the JSP project was correctly created even before you start writing any code. When executed, an empty project (like the one you just created) will allow you to view the contents of the project's '''ROOT''' directory.

* Open a command prompt
* Change directory to your project's ''ROOT'' directory within your Eclipse workspace
** In the CASLAB, this will typically be the commands:
*** '''Z:'''
*** '''cd Workspace\Example\ROOT'''
* Execute the command '''winstone'''
** You should see the message ''HTTP Listener started: port-8080''

=== Testing your Winstone Server ===
To test that your Winstone server is running, open a web browser, and point it to '''http://127.0.0.1:8080'''. You should see a directory listing showing no files, with a message similar to ''Directory list generated by Winstone Servlet Engine v0.9.9 at Sat Sep 08 15:10:22 EDT 2007''.

== Creating a JSP Program ==
The combination of Eclipse and Winstone makes creating JSP pages very easy. The short version is that you need to create a file with a '''.jsp''' extension in the '''ROOT''' directory of your project.

These instructions assume you are working in a project created following the instructions given above.

=== Configuring Eclipse to Edit JSPs ===
Eclipse does not contain a JSP editor. We will simply use Eclipse's text editor for JSPs. To do this:
* Open ''Window|Preferences...''
* Open ''General|Editors|File Associations''
* Click ''Add...'' under ''File types''
** In the dialogue, enter ''*.jsp''
* Click ''Add...'' under ''Associated editors''
** Select ''Text editor'' in the dialogue
You only need to perform this step once.

=== Editing a JSP ===
Right-click on the '''ROOT''' folder in the ''Package Explorer'' pane. Select '''New''' and '''File'''. A dialog with the header ''Create a file resource'' will appear.

Ensure that the '''ROOT''' folder is selected in the dialogue. Select it if it is not.

Enter '''index.jsp''' in the ''File name'' field and click '''Finish'''. The dialogue will disappear and an '''index.jsp''' file will appear in the '''ROOT''' folder.

If you need a quick example of the features available in JSP, paste the following into the editor:

 <%@ page import="java.io.*"
          import="java.util.*" %>
 
 <!-- This declaration creates a java.util.HashMap named 'map'
      which will be shared across all views of this page. It can
      be accessed from Java code as shown. -->
 <jsp:useBean id="map" scope="page" class="java.util.HashMap"/>
 
 <html>
 <head></head>
 <body>
 
 <% /* This starts a block of Java code */
 
     map.put("key", "value");
     map.put("foo", "bar");
     map.put("baz", "woo");
     
 %> <!-- This ends a block of Java code -->
 
 <!-- This shows the inline use of Java expressions -->
 The value of 'key' is: <%= map.get("key") %>
 
 &lt;table>
 <%
     /* loops and conditionals can include HTML content */
     for (Iterator it = map.entrySet().iterator(); it.hasNext(); )
     {
         Map.Entry entry = (Map.Entry) it.next();
 %>
 &lt;tr>&lt;td><%= entry.getKey() %>&lt;/td>&lt;td><%= entry.getValue() %>&lt;/td>&lt;/tr>
 <%  } %>
 &lt;/table>
 
 <%
     /* to access parameters supplied by the browser, use
        the 'request' object */
 
     String username = request.getParameter("username");
     if (username != null)
     {
 	/* the response.sendError method can be used to
           deliver HTTP errors. */
  	response.sendError(HttpServletResponse.SC_FORBIDDEN,
 		"You tried to specify a username parameter");
     }
 
 %>
 
 </body>
 </html>

=== Running a JSP ===
To view your JSP, simply browse to '''http://127.0.0.1:8080/index.jsp'''.

=== Java Classes and JSPs ===
When creating Java classes to be used from the JSPs, you must place them in a non-default package (i.e. they must have a package declaration). JSP files are compiled to Java classes in a package chosen by the container, so can not easily access classes from the default package.