uk.ac.ed.epcc.webapp.servlet

Interface ServletService

All Superinterfaces:

AppContextCleanup, AppContextService<ServletService>, Contexed

All Known Implementing Classes:

DefaultServletService, MultiPartServletService, Servlet3MultiPartServletService

public interface ServletService
extends AppContextService<ServletService>, Contexed

An AppContextService used to access the servlet environment. This is intended to abstract logic that behaves differently in HttpServlet, Web-service and Portlet environments. The request/response objects are usually encapsulated in this object. These should not be exposed in the external interface as Portlets use different classes from servlets.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	DEFAULT_PAYLOAD_PARAM

Method Summary

Modifier and Type	Method and Description
void	addErrorProps(java.util.Map props) Add additional information about the request to the properties of a debugging error report email.
java.lang.String	defaultCharset() Return the default charset we want to use.
java.lang.String	encodePage() un-encoded version of the original request page.
java.lang.String	encodeURL(java.lang.String url) Add the context path to a url path
void	forward(java.lang.String url) Forward request to a different page.
java.util.LinkedList<java.lang.String>	getArgs() Get the ServletPath as a list of strings A path element of "-" terminates the list.
java.lang.Iterable<java.lang.String>	getAttributeNames()
java.util.Map<java.lang.String,java.lang.Object>	getParams() Extract a Map of the request parameters from the request.
java.lang.Object	getRequestAttribute(java.lang.String name) Retrieve an object from the current request.
default MimeStreamData	getStreamParam(java.lang.String name)
default java.lang.String	getTextParameter(java.lang.String name) get a named paramter as a string This should include conversion f uplaoded files etc.
java.lang.String	getWebName() get the authenticated name for the current user as provided by the web-server/container authorisation layer.
boolean	isComitted() Has the response been comitted.
void	noCache() Identify the current request as containing sensative data that should not be cached.
<A extends AppUser> void	populateSession(SessionService<A> sess) Populate a session automatically using information from the request.
void	redirect(java.lang.String url) Redirect request to a different page.
void	redirect(java.net.URI uri) Redirect to an external URI This is intended for external URLs so session is never encoded
<A extends AppUser> void	requestAuthentication(SessionService<A> sess) Authentication is required for this request but credentials are not available.
<A extends AppUser> void	requestLogin(SessionService<A> sess, java.lang.String page) Go to the login page to request a login.
void	setRequestAttribute(java.lang.String name, java.lang.Object value) Store an object in the current request
void	setTimeout(int seconds) Set an inactivity timeout if supported

Methods inherited from interface uk.ac.ed.epcc.webapp.AppContextService

getType

Methods inherited from interface uk.ac.ed.epcc.webapp.AppContextCleanup

cleanup

Methods inherited from interface uk.ac.ed.epcc.webapp.Contexed

getContext

Field Detail

DEFAULT_PAYLOAD_PARAM

static final java.lang.String DEFAULT_PAYLOAD_PARAM

See Also:

Constant Field Values

Method Detail

encodePage

java.lang.String encodePage()

un-encoded version of the original request page. * This uses a cached value because the request URL will be re-written if the request is forwarded to a different servlet/jsp.

Returns:

String URL relative to context root.

encodeURL

java.lang.String encodeURL(java.lang.String url)

Add the context path to a url path

Parameters:

url -

Returns:

String

forward

void forward(java.lang.String url)
      throws ServletException,
             java.io.IOException

Forward request to a different page.

Parameters:

url - String page to forward to relative to the context path

Throws:

ServletException

java.io.IOException

redirect

void redirect(java.lang.String url)
       throws java.io.IOException

Redirect request to a different page.

Parameters:

url - String page to forward to relative to the context path

Throws:

ServletException

java.io.IOException

redirect

void redirect(java.net.URI uri)
       throws java.io.IOException

Redirect to an external URI This is intended for external URLs so session is never encoded

Parameters:

uri -

Throws:

java.io.IOException

getParams

java.util.Map<java.lang.String,java.lang.Object> getParams()

Extract a Map of the request parameters from the request. This is made a method on the ServletAppContext to allow access to logging/configuration and to allow the application specific customisation.

Returns:

Map of parameters

Throws:

DataFault

getTextParameter

default java.lang.String getTextParameter(java.lang.String name)

get a named paramter as a string This should include conversion f uplaoded files etc.

Parameters:

name -

Returns:

getStreamParam

default MimeStreamData getStreamParam(java.lang.String name)
                               throws DataFault

Throws:

DataFault

getArgs

java.util.LinkedList<java.lang.String> getArgs()

Get the ServletPath as a list of strings A path element of "-" terminates the list. This is to allow parameters to be passed on the path at the same time as an arguemnt path.

Returns:

LinkedList arguments in order.

getWebName

java.lang.String getWebName()

get the authenticated name for the current user as provided by the web-server/container authorisation layer. This will be null unless the container/web-server has authorisation turned on for this URL.

Returns:

String webname

populateSession

<A extends AppUser> void populateSession(SessionService<A> sess)

Populate a session automatically using information from the request. This is invoked by the ServletSessionService if a person is requested and the current person is not stored in the session. It handles authentication mechanisms that don't use a specific login url. If the session is not populated here it may trigger a call to requestAuthentication(SessionService) later. Any authentication errors could be cached in the request and handled there.

Parameters:

sess - SessionService

requestAuthentication

<A extends AppUser> void requestAuthentication(SessionService<A> sess)
                                        throws java.io.IOException,
                                               ServletException

Authentication is required for this request but credentials are not available. If possible this should request the client to re-send the request with correct authorisation. e.g. by redirecting to a login page or requesting basic authentication. The request could take account of authentication errors from an earlier call to populateSession(SessionService). These can be cahce din the request. The SessionService is provided as a parameter to be queried for its capabilities.

Parameters:

sess - SessionService

Throws:

java.io.IOException

ServletException

requestLogin

<A extends AppUser> void requestLogin(SessionService<A> sess,
                                      java.lang.String page)
                               throws java.io.IOException,
                                      ServletException

Go to the login page to request a login.

Type Parameters:

A -

Parameters:

sess - SessionService

page - page to return to

Throws:

java.io.IOException

ServletException

defaultCharset

java.lang.String defaultCharset()

Return the default charset we want to use.

Returns:

isComitted

boolean isComitted()

Has the response been comitted.

Returns:

addErrorProps

void addErrorProps(java.util.Map props)

Add additional information about the request to the properties of a debugging error report email.

Parameters:

props -

noCache

void noCache()

Identify the current request as containing sensative data that should not be cached.

getAttributeNames

java.lang.Iterable<java.lang.String> getAttributeNames()

setRequestAttribute

void setRequestAttribute(java.lang.String name,
                         java.lang.Object value)

Store an object in the current request

Parameters:

name -

value -

getRequestAttribute

java.lang.Object getRequestAttribute(java.lang.String name)

Retrieve an object from the current request.

Parameters:

name -

Returns:

setTimeout

void setTimeout(int seconds)

Set an inactivity timeout if supported

Parameters:

seconds -