2.5.1. Integration into Apache 1.3

First, add

LoadModule jk_module /usr/lib/apache/1.3/mod_jk.so

The /etc/apache/workers.properties file should look like this:

worker.list=worker1

# Set properties for worker1 (ajp13)
 worker.worker1.type=ajp13
 worker.worker1.host=localhost
 worker.worker1.port=8009
 worker.worker1.lbfactor=50
 worker.worker1.cachesize=10
 worker.worker1.cache_timeout=600
 worker.worker1.socket_keepalive=1
 worker.worker1.socket_timeout=300

# workers.properties file: where httpd.conf is
JkWorkersFile /etc/apache/workers.properties

# Where to put jk logs
JkLogFile /var/log/apache/jk.log

# Set the jk log level [debug/error/info]
JkLogLevel info

# Select the log format
JkLogStampFormat "[%a %b %d %H:%M:%S %Y] "

# JkOptions indicate to send SSL KEY SIZE,
JkOptions +ForwardKeySize +ForwardURICompat -ForwardDirectories

# JkRequestLogFormat set the request format
JkRequestLogFormat "%w %V %T"

# Send everything for context /examples to worker named worker1 (ajp13)
JkMount /test/* worker1

2.5.2. Integration into Apache 2

The /etc/apache2/workers2.properties file should look like:

[lb:lb]
info=Default load balancer.
debug=0

[channel.socket:localhost:8009]
info=Ajp13 forwarding over socket
debug=0
tomcatId=localhost:8009

[status:]
info=Status worker, displays runtime informations

[uri:/jkstatus/*]
info=Display status information and checks the config file for changes.
group=status:

[uri:/test/*]
info=Map the whole webapp
	  

The /etc/apache2/mods-enabled/jk2.conf file:

# To enable mod_jk2, customize workers2.properties* from
# /usr/share/doc/libapache2-mod-jk2/examples and copy it to
# /etc/apache2/workers2.properties. Then uncomment the following line:
JkSet config.file /etc/apache2/workers2.properties
	  

2.5.3. Integration into IIS™

t.b.d.

3.3.1. The NAnt build file

Let's have a look at the NAnt build file:

<?xml version="1.0"?>
 <project name="TestServlet" default="build" basedir=".">
    <description>Building a TestServlet for Othello Servlet Container</description>
    <property name="debug" value="false" overwrite="false" />
    <property name="dist" value="dist"/>

    <target name="clean" description="remove dist">
        <delete dir="${dist}" failonerror="false" />
    </target>

    <target name="build" description="compiles the source code">
	<mkdir dir="${dist}" failonerror="false"/>

        <csc target="library" output="${dist}/TestServlet.dll" debug="${debug}">
            <sources basedir="src">
                <include name="*.cs" />
            </sources>
	    <references>
	        <include name="lib/*.dll" />
	    </references>
	    <resources>
	        <include name="etc/*" />
	    </resources>
        </csc>
    </target>
</project>

3.3.2. The servlet configuration

As known for Java servlets, each servlet needs a configuration. This configuration is read by the servlet container to determine how to expose the servlet. This file is called web.xml and needs to be added add resource to a peace file. Let's have a look at the servlet configuration for our Test Servlet:

 <?xml version="1.0" encoding="ISO-8859-1"?>
 <web-app>
  <context-param>
    <param-name>ContextParam</param-name> 
    <param-value>An example context parameter</param-value> 
  </context-param>
  <servlet>
	<servlet-name>TestServlet</servlet-name>
	<servlet-class>TestServlet</servlet-class> 
	<load-on-startup>1</load-on-startup>
  </servlet>
  <welcome-file-list>
	<welcome-file>welcome.html</welcome-file>
	<welcome-file>index.html</welcome-file>
  </welcome-file-list>

  <servlet-mapping>
    <servlet-name>TestServlet</servlet-name>
    <url-pattern>/test/TestServlet</url-pattern>
  </servlet-mapping>
</web-app>
			

The next section servlet configures the servlet itself. It contains the name of the servlet and the name of the serlvet-class. The servlet class definition needs to be configured with full namespace. Furthermore, it is optionally possible to define parameters that are passed to the servlet on initialisation (init-param). Additionally, the parameter load-on-startup defines, wether the servlet should be started when the servlet container starts or on first request towards the servlet.

The next major section welcome-file-list defines, which files the servlet container should check for in the servlet resources and display, even only the servlet path is given. The order of the welcome-file- list matters.

The most important section in the servlet configuration is servlet-mapping. It maps the URL that is exposed by the servlet container to the servlet. In this example, we map test/TestServlet on TestServlet.

3.3.3. The servlet code

Let's now have a look at a typical simple servlet. First of all: Every servlet has to extend the class HttpServlet and needs to implement its abstract methods: Init (called on servlet initialisation),Destroy (called on servlet shutdown),DoGet and DoPost (called when a request comes in from a client). DoGet and DoPost have two parameters of type HttpServletRequest and HttpServletResponse.

These parameters contain the incoming information from the client (Request) while the response to the client is stored in the Response parameter.

In this example, we simply print out some of the information that we get on the initialisation of the servlet into the Othello standard log channel (method Init). On a request, we write some of the information that we received from the request into the Servlet Output Stream and therewith to the client. Since most of the clients are HTML-enabled (web browsers), the output is contructed and returned as HTML (methods DoGet and DoPost).

using MonoServletAPI;

using System; 
using System.Collections;
using MonoServletAPI.Http;

public class TestServlet:HttpServlet {
	public override void Init() {		
		// print servlet name, context and init parameters
		Console.WriteLine("ServletName:"+this.config.GetServletName());
		Console.WriteLine("ServletName:"+this.config.GetServletContext());
		Console.WriteLine("InitParameters");
		IEnumerator it=this.config.GetInitParameterNames();
		while(it.MoveNext()) {
			string param=(string)it.Current;
			Console.WriteLine(param+"="+this.config.GetInitParameter(param));
		}
	}
	
	public override void Destroy() {
		Console.WriteLine("DESTROY CALLED");
	}
	
	public override void DoGet(HttpServletRequest req, HttpServletResponse res) {
		DoPost(req,res); // get and post shall behave the same way, just pass it over
	}
	
	public override void DoPost(HttpServletRequest req, HttpServletResponse res) {
		// get output stream and set content type
		ServletOutputStream s=res.GetOutputStream();
		res.SetContentType("text/html");
	
		// some general request information	
		s.WriteLine("<h1>Some output from test servlet...</h1>");
		s.WriteLine("<br><b>GetProtocol: </b>"+req.GetProtocol());
		s.WriteLine("<br><b>QueryString: </b>"+req.GetQueryString());
		s.WriteLine("<br><b>RemoteAddr: </b>"+req.GetRemoteAddr());
		s.WriteLine("<br><b>RemoteHost: </b>"+req.GetRemoteHost());
		s.WriteLine("<br><b>RequestURI: </b>"+req.GetRequestURI());
		s.WriteLine("<br><b>RequestURL: </b>"+req.GetRequestURL());
		s.WriteLine("<br><b>Session: </b>"+req.GetSession());
		s.WriteLine("<br><b>RequestedSessionId: </b>"+req.GetRequestedSessionId());
		
		// print the parameters given from the request
		s.WriteLine("<p>Parameters<br>");
		it=req.GetParameterNames();
		while(it.MoveNext()) {
			string paramName=(string)it.Current;
			s.WriteLine("<b>"+paramName+"</b>="+req.GetParameter(paramName)+"<br>");	
		}

		// print the cookies, if any
		s.WriteLine("<p>Cookies<br>");
		Cookie[] cookies=req.GetCookies();
		for(int i=0;i<cookies.Length;i++) {
			s.WriteLine(
			"Name="+cookies[i].GetName()+
			", Value="+cookies[i].GetValue()+
			", Path="+cookies[i].GetPath()+
			", Secure="+cookies[i].GetSecure()+ 
			", Type="+cookies[i].GetType()+
			", Version="+cookies[i].GetVersion()+
			", Comment="+cookies[i].GetComment()+
			", Domain="+cookies[i].GetDomain()+
			", HashCode="+cookies[i].GetHashCode()+
			", MaxAge="+cookies[i].GetMaxAge()+
			"<br>");
		}
		s.Close();
	}
}