com.pmdesigns.jvc
Class JVCRequestContext

java.lang.Object
  com.pmdesigns.jvc.JVCRequestContext

public final class JVCRequestContext
extends java.lang.Object

This class contains state information for processing an http request. It wraps the standard HttpServletRequest, HttpServletResponse and HttpServlet objects and provides convenience methods for accessing them.

It also provides access to the 'flash' which is a Map for storing temporary key/value strings. The scope of the flash is the current request or the following request in the case of a redirect response.

It also contains some convenience methods for forming links and absolute paths.

Author:

mike dooley

Field Summary

java.lang.String	action The action is the last part of the servlet path (before any query arguments)
java.lang.String	controller The controller is the servlet path up to the action.
java.util.Map<java.lang.String,java.lang.String>	flash The 'flash' map for holding temporary key/value strings.
javax.servlet.http.HttpServletRequest	request The actual HttpServletRequest object
javax.servlet.http.HttpServletResponse	response The actual HttpServletResponse object
javax.servlet.http.HttpServlet	servlet The HttpServlet object (actually this is a JVCDispatcher)

Method Summary

java.lang.String	absPath(java.lang.String path) Convenience method to prepend the context path onto a servlet path
static java.lang.String	getCachedBlock(java.lang.String key) Internal method used to retrieve a cached block
java.lang.String	getContextPath() Convenience method.
javax.servlet.http.Cookie	getCookie(java.lang.String name) Convenience method to get cookie by name
java.lang.String[]	getCookieNames() Convenience method to get all the cookie names.
java.lang.String	getFlash(java.lang.String key) Convenience method to retrieve a value from the flash
java.lang.String	getMethod() Convenience method
java.lang.String	getParam(java.lang.String name) Convenience method
java.util.Map<java.lang.String,java.lang.String>	getParamMap(java.lang.String name) Convenience method which gathers all parameters of the form '[]' and return then in a map where the keys are the strings and the values are the corresponding parameter values.
java.lang.String[]	getParamNames() Convenience method to get all the parameter names.
java.lang.String[]	getParamValues(java.lang.String name) Convenience method.
java.lang.String	getQueryString() Convenience method.
java.lang.String	getScheme() Convenience method
java.lang.String	getServerName() Convenience method
int	getServerPort() Convenience method
java.lang.String	getServletPath() Convenience method.
java.lang.Object	getSessionAttr(java.lang.String name) Convenience method
java.lang.String[]	getSessionAttrNames() Convenience method
boolean	isGet() Convenience method to check if this request is a GET
boolean	isPost() Convenience method to check if this request is a POST
boolean	isSecure() Convenience method
java.lang.String	makeLink(java.lang.String anchor, java.lang.String path) Convenience method to create an html anchor link tag
java.lang.String	makeLink(java.lang.String anchor, java.lang.String path, java.lang.String options) Convenience method to create an html anchor link tag
void	nonStandardResponse(int httpCode, java.lang.String arg) Cause a non-standard response (ie. redirect) to be returned.
void	redirect(java.lang.String path) Cause a redirect response to be returned
void	removeSessionAttr(java.lang.String name) Convenience method
static void	setCachedBlock(java.lang.String key, java.lang.String val) Internal method used to store a cached block
void	setCookie(javax.servlet.http.Cookie cookie) Convenience method
void	setFlash(java.lang.String key, java.lang.String val) Convenience method to add a value to the flash
void	setSessionAttr(java.lang.String name, java.lang.Object value) Convenience method
java.lang.String	toString() For debugging
java.lang.String	toString(java.lang.String sep)

Methods inherited from class java.lang.Object

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

Field Detail

request

public final javax.servlet.http.HttpServletRequest request

The actual HttpServletRequest object

response

public final javax.servlet.http.HttpServletResponse response

The actual HttpServletResponse object

servlet

public final javax.servlet.http.HttpServlet servlet

The HttpServlet object (actually this is a JVCDispatcher)

controller

public final java.lang.String controller

The controller is the servlet path up to the action.

action

public final java.lang.String action

The action is the last part of the servlet path (before any query arguments)

flash

public final java.util.Map<java.lang.String,java.lang.String> flash

The 'flash' map for holding temporary key/value strings.

Method Detail

isSecure

public boolean isSecure()

Convenience method

Returns:

true if the request is secure

getScheme

public java.lang.String getScheme()

Convenience method

Returns:

the request scheme, ie. http, https

getMethod

public java.lang.String getMethod()

Convenience method

Returns:

the request method, ie. GET, POST

getServerName

public java.lang.String getServerName()

Convenience method

Returns:

the server name for this request

getServerPort

public int getServerPort()

Convenience method

Returns:

the server port for this request

getContextPath

public java.lang.String getContextPath()

Convenience method. The request url path is broken into:

• context path
• servlet path
• query string

Returns:

the context path part of the url path

See Also:

getServletPath(), getQueryString()

getServletPath

public java.lang.String getServletPath()

Convenience method. The request url path is broken into:

• context path
• servlet path
• query string

Returns:

the servlet path part of the url path

See Also:

getContextPath(), getQueryString()

getQueryString

public java.lang.String getQueryString()

Convenience method. The request url path is broken into:

• context path
• servlet path
• query string

Returns:

the query string part of the url path

See Also:

getContextPath(), getServletPath()

getParam

public java.lang.String getParam(java.lang.String name)

Convenience method

Parameters:

name - which parameter to get

Returns:

the parameter value or null

See Also:

getParamMap(java.lang.String), getParamValues(java.lang.String), getParamNames()

getParamMap

public java.util.Map<java.lang.String,java.lang.String> getParamMap(java.lang.String name)

Convenience method which gathers all parameters of the form '[]' and return then in a map where the keys are the strings and the values are the corresponding parameter values.

 For example, if there are parameters:
   'foo[bar1]' = 'baz1'
   'foo[bar2]' = 'baz2'
 then getParamMap('foo') will returned the map:
   map['bar1'] = 'baz1'
   map['bar2'] = 'baz2'
 

Parameters:

name - the prefix to be used to select parameters

Returns:

a map of all paramters of the form 'name[]' where the strings are the keys of the map and the values are the corresponding parameter values.

See Also:

getParam(java.lang.String), getParamValues(java.lang.String), getParamNames()

getParamValues

public java.lang.String[] getParamValues(java.lang.String name)

Convenience method. Use this if you expect a parameter name to map to multiple values.

Parameters:

name - the name of the parameter(s) to get

Returns:

an array of paramter values corresponding to the indicated name

See Also:

getParam(java.lang.String), getParamMap(java.lang.String), getParamNames()

getParamNames

public java.lang.String[] getParamNames()

Convenience method to get all the parameter names.

Returns:

an array of all parameter names

See Also:

getParam(java.lang.String), getParamMap(java.lang.String), getParamValues(java.lang.String)

getSessionAttr

public java.lang.Object getSessionAttr(java.lang.String name)

Convenience method

Parameters:

name - the name of the attribute to retrieve

Returns:

the attribute associated with the indicated name or null

See Also:

setSessionAttr(java.lang.String, java.lang.Object), getSessionAttrNames()

getSessionAttrNames

public java.lang.String[] getSessionAttrNames()

Convenience method

Returns:

all the session attribute names.

See Also:

getSessionAttr(java.lang.String), setSessionAttr(java.lang.String, java.lang.Object), removeSessionAttr(java.lang.String)

setSessionAttr

public void setSessionAttr(java.lang.String name,
                           java.lang.Object value)

Convenience method

Parameters:

name - the key to store the indicated value

value - the object to be stored

See Also:

getSessionAttr(java.lang.String), removeSessionAttr(java.lang.String)

removeSessionAttr

public void removeSessionAttr(java.lang.String name)

Convenience method

Parameters:

name - the key of

See Also:

setSessionAttr(java.lang.String, java.lang.Object)

getCookie

public javax.servlet.http.Cookie getCookie(java.lang.String name)

Convenience method to get cookie by name

Parameters:

name - the name of the cookie to get

Returns:

the cookie with the indicated name, or null

See Also:

setCookie(javax.servlet.http.Cookie), getCookieNames()

getCookieNames

public java.lang.String[] getCookieNames()

Convenience method to get all the cookie names.

Returns:

an array of the names of all the cookies in the request, possibly empty

See Also:

getCookie(java.lang.String), setCookie(javax.servlet.http.Cookie)

setCookie

public void setCookie(javax.servlet.http.Cookie cookie)

Convenience method

Parameters:

cookie - the cookie to be added to the response

See Also:

getCookie(java.lang.String), getCookieNames()

nonStandardResponse

public void nonStandardResponse(int httpCode,
                                java.lang.String arg)

Cause a non-standard response (ie. redirect) to be returned.

Parameters:

httpCode - the http response code to be returned

arg - an argument or message to be returned (depends on response code)

Throws:

NonStandardResponseException - which is a subclass of RuntimeException. If you call this method inside a try/catch block make sure you re-throw the NonStandardResponseException.

See Also:

redirect(java.lang.String)

redirect

public void redirect(java.lang.String path)

Cause a redirect response to be returned

Parameters:

path - where to redirect to. If the path starts with a '/' character then its assumed that this is an absolute link and the context path will be prepended to it

Throws:

NonStandardResponseException - which is a subclass of RuntimeException. If you call this method inside a try/catch block make sure you re-throw the NonStandardResponseException.

See Also:

nonStandardResponse(int, java.lang.String)

absPath

public java.lang.String absPath(java.lang.String path)

Convenience method to prepend the context path onto a servlet path

Parameters:

path - a servlet path

Returns:

the context path plus the indicated path

makeLink

public java.lang.String makeLink(java.lang.String anchor,
                                 java.lang.String path)

Convenience method to create an html anchor link tag

Parameters:

anchor - the text in an anchor link

path - the anchor target, if the path starts with a '/' character then its assumed that this is an absolute link and the context path will be prepended to it

See Also:

makeLink(java.lang.String, java.lang.String), absPath(java.lang.String)

makeLink

public java.lang.String makeLink(java.lang.String anchor,
                                 java.lang.String path,
                                 java.lang.String options)

Convenience method to create an html anchor link tag

Parameters:

anchor - the text in an anchor link

path - the anchor target, if the path starts with a '/' character then its assumed that this is an absolute link and the context path will be prepended to it

options - extra html options to add to the anchor tag

See Also:

makeLink(java.lang.String, java.lang.String), absPath(java.lang.String)

isPost

public boolean isPost()

Convenience method to check if this request is a POST

isGet

public boolean isGet()

Convenience method to check if this request is a GET

getFlash

public java.lang.String getFlash(java.lang.String key)

Convenience method to retrieve a value from the flash

Parameters:

key - the key to use to lookup a flash value

Returns:

the flash value associated with the indicated key or null

See Also:

setFlash(java.lang.String, java.lang.String)

setFlash

public void setFlash(java.lang.String key,
                     java.lang.String val)

Convenience method to add a value to the flash

Parameters:

key - the key to use to associate with the flash value

val - the value to store

See Also:

getFlash(java.lang.String)

getCachedBlock

public static java.lang.String getCachedBlock(java.lang.String key)

Internal method used to retrieve a cached block

See Also:

setCachedBlock(java.lang.String, java.lang.String)

setCachedBlock

public static void setCachedBlock(java.lang.String key,
                                  java.lang.String val)

Internal method used to store a cached block

See Also:

getCachedBlock(java.lang.String)

toString

public java.lang.String toString()

For debugging

Overrides:

toString in class java.lang.Object

Returns:

a string representation of this request context

toString

public java.lang.String toString(java.lang.String sep)