org.szegedi.expose.servlet
Class ExposeServlet

java.lang.Object
  |
  +--javax.servlet.GenericServlet
        |
        +--javax.servlet.http.HttpServlet
              |
              +--org.szegedi.expose.servlet.ExposeServlet

All Implemented Interfaces:

java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public class ExposeServlet

extends javax.servlet.http.HttpServlet

This is a general-purpose Freemarker servlet with following features:

• It utilizes a TemplateCache that is fully parametrizable
• It makes all request, request parameters, session, and servlet context attributes available to templates through "Request", "RequestParameters", "Session", and "Application" variables. The implementation for these variables is efficient; rather than copying the attributes and parameters into SimpleHash, special wrapper classes are used that implement the TemplateHashModel interface.

Supported initialization parameters are:

• TemplatePath specifies the location of the templates. By default, the location is the web application-relative URI of the location. Alternatively, you can prepend it with file:// to indicate path in the file system (i.e. file:///var/www/project/templates/). Note that three slashes were specified. Default value is / (that is, the root of the web application).
• TemplateUpdateInterval value for update interval of the template cache in milliseconds. Default is 60000 (ten minutes)
• NoCache if set to true, generates headers in the response that advise the HTTP client not to cache the returned page. Default false

Version:

1.0

Author:

Attila Szegedi, attila@szegedi.org

See Also:

Serialized Form

Field Summary

protected boolean	debug
static long	serialVersionUID

Constructor Summary

ExposeServlet()

Method Summary

protected freemarker.template.TemplateCache	createCache()
protected HttpRequestParametersHashModel	createRequestParametersHashModel(javax.servlet.http.HttpServletRequest request)
void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
void	doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
void	init()
protected void	initializeServletContext(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Called when servlet detects in a request processing that application-global (that is, ServletContext-specific) attributes are not yet set.
protected void	initializeSession(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Called when servlet detects in a request processing that session-global (that is, HttpSession-specific) attributes are not yet set.
protected void	postTemplateProcess(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, freemarker.template.Template template, freemarker.template.TemplateModelRoot data) Called after the execution returns from template.process().
protected boolean	preTemplateProcess(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, freemarker.template.Template template, freemarker.template.TemplateModelRoot data) Called before the execution is passed to template.process().

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doOptions, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

serialVersionUID

public static final long serialVersionUID

debug

protected boolean debug

Constructor Detail

ExposeServlet

public ExposeServlet()

Method Detail

init

public void init()

Overrides:

init in class javax.servlet.GenericServlet

createCache

protected freemarker.template.TemplateCache createCache()

doGet

public void doGet(javax.servlet.http.HttpServletRequest request,
                  javax.servlet.http.HttpServletResponse response)
           throws javax.servlet.ServletException,
                  java.io.IOException

Overrides:

doGet in class javax.servlet.http.HttpServlet

doPost

public void doPost(javax.servlet.http.HttpServletRequest request,
                   javax.servlet.http.HttpServletResponse response)
            throws javax.servlet.ServletException,
                   java.io.IOException

Overrides:

doPost in class javax.servlet.http.HttpServlet

createRequestParametersHashModel

protected HttpRequestParametersHashModel createRequestParametersHashModel(javax.servlet.http.HttpServletRequest request)

initializeServletContext

protected void initializeServletContext(javax.servlet.http.HttpServletRequest request,
                                        javax.servlet.http.HttpServletResponse response)
                                 throws javax.servlet.ServletException,
                                        java.io.IOException

Called when servlet detects in a request processing that application-global (that is, ServletContext-specific) attributes are not yet set. This is a generic hook you might use in subclasses to perform a specific action on first request in the context. By default it does nothing.

Parameters:

request - the actual HTTP request

response - the actual HTTP response

initializeSession

protected void initializeSession(javax.servlet.http.HttpServletRequest request,
                                 javax.servlet.http.HttpServletResponse response)
                          throws javax.servlet.ServletException,
                                 java.io.IOException

Called when servlet detects in a request processing that session-global (that is, HttpSession-specific) attributes are not yet set. This is a generic hook you might use in subclasses to perform a specific action on first request in the session. By default it does nothing.

Parameters:

request - the actual HTTP request

response - the actual HTTP response

preTemplateProcess

protected boolean preTemplateProcess(javax.servlet.http.HttpServletRequest request,
                                     javax.servlet.http.HttpServletResponse response,
                                     freemarker.template.Template template,
                                     freemarker.template.TemplateModelRoot data)
                              throws javax.servlet.ServletException,
                                     java.io.IOException

Called before the execution is passed to template.process(). This is a generic hook you might use in subclasses to perform a specific action before the template is processed. By default does nothing. A typical action to perform here is to inject application-specific objects into the TemplateModelRoot.

Parameters:

request - the actual HTTP request

response - the actual HTTP response

template - the template that will get executed

data - the data that will be passed to the template

Returns:

true to process the template, false to suppress template processing.

postTemplateProcess

protected void postTemplateProcess(javax.servlet.http.HttpServletRequest request,
                                   javax.servlet.http.HttpServletResponse response,
                                   freemarker.template.Template template,
                                   freemarker.template.TemplateModelRoot data)
                            throws javax.servlet.ServletException,
                                   java.io.IOException

Called after the execution returns from template.process(). This is a generic hook you might use in subclasses to perform a specific action after the template is processed. It will be invoked even if the template processing throws an exception. By default does nothing.

Parameters:

request - the actual HTTP request

response - the actual HTTP response

template - the template that was executed

data - the data that was passed to the template