com.jdc.http.mvc
Class HttpModel

java.lang.Object
  |
  +--jdc.java.lang.Object
        |
        +--com.jdc.app.mvc.Model
              |
              +--com.jdc.http.mvc.HttpModel

public abstract class HttpModel

extends Model

HttpModel processes the user request, i.e. it is the Model in a Model-View-Controller (MVC) framework. Handles to the following implicit objects are provided to simpify usage by classes extending this class: request - The current HTTP servlet request object. response - The current HTTP servlet response object. session - The current HTTP user session object. user - The current user profile object browser - The type of browser in use.

Version:

1.0

Author:

Jay Damon

See Also:

Serialized Form

Field Summary

protected Browser	browser The type of browser used by the user to make the current request, e.g.
protected ServletConfig	config The current servlet configuration object, if provided.
protected ServletContext	context The current servlet context object, if provided.
protected HttpServletRequest	request The current HTTP servlet request object.
protected HttpServletResponse	response The current HTTP servlet response object.
protected HttpSession	session The current HTTP user session object.
protected HttpTransaction	transaction The current user transaction object.
protected HttpUserProfile	user The current user, i.e.
protected HttpView	view The current user view object.

Fields inherited from class com.jdc.app.mvc.Model

currency, locale, log, number, string, timestamp, USER, VIEW

Constructor Summary

HttpModel(HttpServletRequest request, HttpServletResponse response)
Constructs an HttpModel object.

HttpModel(HttpServletRequest request, HttpServletResponse response, ServletContext context)
Constructs a HttpModel object.

HttpModel(HttpServletRequest request, HttpServletResponse response, ServletContext context, ServletConfig config)
Constructs a HttpModel object.

Method Summary

String	addContext(String requestURL) Adds the web application context to fully qualify a url.
boolean	areCookiesEnabled() Returns true if cookies are enabled.
void	createCookie(String name, String value, int hours) Creates a cookie to be stored on the user's computer.
protected void	displayCookies() Displays current request cookies.
protected void	displayRequestParameters() Displays current request parameters.
HttpModel	doRequest() Handles the current HTTP servlet request.
abstract HttpView	doRequest(HttpView view) Handles the current HTTP servlet request.
Browser	getBrowser() Returns the type of browser used by the user to make the current request.
ServletConfig	getConfig() Returns the current servlet configuration object, if provided.
ServletContext	getContext() Returns the current servlet context object, if provided..
String	getCookieValue(String cookieName) Returns the cookie value for the requested cookie name, if the cookie exists.
Locale	getLocale() Returns the user locale object.
String	getParameterValue(String parameterName) Returns the parameter value for the requested parameter name, if the parameter exists.
HttpServletRequest	getRequest() Returns the current HTTP servlet request object.
HttpServletResponse	getResponse() Returns the current HTTP servlet response object.
HttpSession	getSession() Returns the current HTTP user session object.
Object	getSessionAttribute(String name) Returns the requested session attribute.
String	getTargetURL() Returns the target Uniform Resource Locator (URL) for the request.
String	getText(String identifier) Returns the resource display text for the specified display text identifier.
String	getText(String identifier, String value) Returns the resource display text for the specified display text identifier.
String	getText(String identifier, String[] values) Returns the resource display text for the specified display text identifier.
String	getText(String identifier, String value1, String value2) Returns the resource display text for the specified display text identifier.
HttpTransaction	getTransaction() Returns the current user transaction object.
HttpUserProfile	getUser() Returns the current user, i.e.
HttpView	getView() Returns the current user view object.
boolean	isGet() Returns true if the method used to invoke current request is GET.
boolean	isPost() Returns true if the method used to invoke current request is POST.
void	setNoCache() Sets the appropriate HTTP servlet response object header to prevent the JSP page from being cached by the client browser.
protected void	setResource(String name) Sets the resource bundle containing page labels and text for the current user locale.
void	setSessionAttribute(String name, Object object) Sets the requested session attribute.

Methods inherited from class com.jdc.app.mvc.Model

setLocale

Methods inherited from class java.lang.Object

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

Field Detail

request

protected HttpServletRequest request

The current HTTP servlet request object.

response

protected HttpServletResponse response

The current HTTP servlet response object.

context

protected ServletContext context

The current servlet context object, if provided.

config

protected ServletConfig config

The current servlet configuration object, if provided.

session

protected HttpSession session

The current HTTP user session object. A new session object will be created if one does not exist.

user

protected HttpUserProfile user

The current user, i.e. client, profile object. A new user profile object will be created if one does not exist.

browser

protected Browser browser

The type of browser used by the user to make the current request, e.g. Microsoft Internet Explorer, Netscape Navigator, etc.

transaction

protected HttpTransaction transaction

The current user transaction object.

view

protected HttpView view

The current user view object.

Constructor Detail

HttpModel

public HttpModel(HttpServletRequest request,
                 HttpServletResponse response)
          throws IllegalArgumentException

Constructs an HttpModel object.

HttpModel

public HttpModel(HttpServletRequest request,
                 HttpServletResponse response,
                 ServletContext context)
          throws RuntimeException

Constructs a HttpModel object.

HttpModel

public HttpModel(HttpServletRequest request,
                 HttpServletResponse response,
                 ServletContext context,
                 ServletConfig config)
          throws RuntimeException

Constructs a HttpModel object.

Method Detail

addContext

public String addContext(String requestURL)

Adds the web application context to fully qualify a url.

Returns:

String

areCookiesEnabled

public boolean areCookiesEnabled()

Returns true if cookies are enabled. This will only work on the first request if there are, in fact, cookies. This cannot be properly tested, however, until the second request, i.e. after the first request actually creates the session and a corresponding session identifier.

Returns:

boolean

createCookie

public void createCookie(String name,
                         String value,
                         int hours)

Creates a cookie to be stored on the user's computer.

displayCookies

protected void displayCookies()

Displays current request cookies. This is a convenience method to display all request cookies to the console

displayRequestParameters

protected void displayRequestParameters()

Displays current request parameters. This is a convenience method to display all request parameters to the console

doRequest

public abstract HttpView doRequest(HttpView view)

Handles the current HTTP servlet request. This method must be implemented in the model subclass.

Returns:

HttpModel This HTTP model object.

doRequest

public HttpModel doRequest()

Handles the current HTTP servlet request. This method invokes doAction() on the model subclass. Upon completion, this method updates the user profile and all associated objects in the session object.

Returns:

HttpModel This HTTP model object.

getBrowser

public Browser getBrowser()

Returns the type of browser used by the user to make the current request. A new browser object is (implicitly) created (by the user object) if one does not exist.

Returns:

Browser The type of browser in use.

getConfig

public ServletConfig getConfig()

Returns the current servlet configuration object, if provided.

Returns:

ServletConfig The servlet configuration object.

getContext

public ServletContext getContext()

Returns the current servlet context object, if provided..

Returns:

ServletContext The servlet context object.

getCookieValue

public String getCookieValue(String cookieName)

Returns the cookie value for the requested cookie name, if the cookie exists.

Returns:

String The cookie value.

getLocale

public Locale getLocale()

Returns the user locale object.

Overrides:

getLocale in class Model

Returns:

Locale The user locale.

getParameterValue

public String getParameterValue(String parameterName)

Returns the parameter value for the requested parameter name, if the parameter exists.

Returns:

String The parameter value.

getRequest

public HttpServletRequest getRequest()

Returns the current HTTP servlet request object.

Returns:

HttpServletRequest The HTTP servlet request object.

getResponse

public HttpServletResponse getResponse()

Returns the current HTTP servlet response object.

Returns:

HttpServletResponse The HTTP servlet response object.

getSession

public HttpSession getSession()

Returns the current HTTP user session object. A new HTTP user session object is created if one does not exist.

Returns:

HttpSession The HTTP user session object.

getTargetURL

public String getTargetURL()

Returns the target Uniform Resource Locator (URL) for the request.

Returns:

String The target URL for the request.

getText

public String getText(String identifier)

Returns the resource display text for the specified display text identifier.

Returns:

String The display text.

getText

public String getText(String identifier,
                      String value)

Returns the resource display text for the specified display text identifier.

Returns:

String The display text.

getText

public String getText(String identifier,
                      String value1,
                      String value2)

Returns the resource display text for the specified display text identifier.

Returns:

String The display text.

getText

public String getText(String identifier,
                      String[] values)

Returns the resource display text for the specified display text identifier.

Returns:

String The display text.

getTransaction

public HttpTransaction getTransaction()

Returns the current user transaction object.

Returns:

HttpTransaction The user transaction object.

getUser

public HttpUserProfile getUser()

Returns the current user, i.e. client, profile object. A new user object is created if one does not exist.

Returns:

HttpUserProfile The user profile object.

getView

public HttpView getView()

Returns the current user view object.

Returns:

HttpView The user view object.

isGet

public boolean isGet()

Returns true if the method used to invoke current request is GET. The servlet invoking this model object must extend servlet class HttpController

Returns:

boolean True if the current request is a GET.

isPost

public boolean isPost()

Returns true if the method used to invoke current request is POST. The servlet invoking this model object must extend servlet class HttpController

Returns:

boolean True if the current request is a POST.

setNoCache

public void setNoCache()

Sets the appropriate HTTP servlet response object header to prevent the JSP page from being cached by the client browser.

setResource

protected void setResource(String name)

Sets the resource bundle containing page labels and text for the current user locale. The user locale defaults to English, via getLocale(), if not specified.

getSessionAttribute

public Object getSessionAttribute(String name)

Returns the requested session attribute.

setSessionAttribute

public void setSessionAttribute(String name,
                                Object object)

Sets the requested session attribute.