Module net.shibboleth.ext.spring

Package net.shibboleth.ext.spring.velocity

Class VelocityView

java.lang.Object

org.springframework.context.support.ApplicationObjectSupport

org.springframework.web.context.support.WebApplicationObjectSupport

org.springframework.web.servlet.view.AbstractView

org.springframework.web.servlet.view.AbstractUrlBasedView

org.springframework.web.servlet.view.AbstractTemplateView

net.shibboleth.ext.spring.velocity.VelocityView

All Implemented Interfaces:

Aware, BeanNameAware, InitializingBean, ApplicationContextAware, ServletContextAware, View

public class VelocityView
extends AbstractTemplateView

View using the Velocity template engine.

Exposes the following JavaBean properties:

• url: the location of the Velocity template to be wrapped, relative to the Velocity resource loader path (see VelocityConfigurer).
• encoding (optional, default is determined by Velocity configuration): the encoding of the Velocity template file
• velocityFormatterAttribute (optional, default=null): the name of the VelocityFormatter helper object to expose in the Velocity context of this view, or null if not needed. VelocityFormatter is part of standard Velocity.
• cacheTemplate (optional, default=false): whether or not the Velocity template should be cached. It should normally be true in production, but setting this to false enables us to modify Velocity templates without restarting the application (similar to JSPs). Note that this is a minor optimization only, as Velocity itself caches templates in a modification-aware fashion.

Note: Spring 3.0's VelocityView requires Velocity 1.4 or higher.

Since:

6.0.0

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	cacheTemplate	Caching flag.
private String	encoding	Template encoding.
private org.apache.velocity.Template	template	The template.
private org.apache.velocity.app.VelocityEngine	velocityEngine	Velocity engine.

Fields inherited from class org.springframework.web.servlet.view.AbstractTemplateView

SPRING_MACRO_REQUEST_CONTEXT_ATTRIBUTE

Fields inherited from class org.springframework.web.servlet.view.AbstractView

DEFAULT_CONTENT_TYPE

Fields inherited from class org.springframework.context.support.ApplicationObjectSupport

logger

Fields inherited from interface org.springframework.web.servlet.View

PATH_VARIABLES, RESPONSE_STATUS_ATTRIBUTE, SELECTED_CONTENT_TYPE

Constructor Summary

Constructors

Constructor	Description
VelocityView()

Method Summary

Modifier and Type	Method	Description
protected org.apache.velocity.app.VelocityEngine	autodetectVelocityEngine()	Autodetect a VelocityEngine via the ApplicationContext.
boolean	checkResource(Locale locale)	Check that the Velocity template used for this view exists and is valid.
protected org.apache.velocity.context.Context	createVelocityContext(Map<String,Object> model)	Create a Velocity Context instance for the given model, to be passed to the template for merging.
protected org.apache.velocity.context.Context	createVelocityContext(Map<String,Object> model, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)	Create a Velocity Context instance for the given model, to be passed to the template for merging.
protected void	doRender(org.apache.velocity.context.Context context, javax.servlet.http.HttpServletResponse response)	Render the Velocity view to the given response, using the given Velocity context which contains the complete template model to use.
protected String	getEncoding()	Return the encoding for the Velocity template.
protected org.apache.velocity.Template	getTemplate()	Retrieve the Velocity template to be rendered by this view.
protected org.apache.velocity.Template	getTemplate(String name)	Retrieve the Velocity template specified by the given name, using the encoding specified by the "encoding" bean property.
protected org.apache.velocity.app.VelocityEngine	getVelocityEngine()	Return the VelocityEngine used by this view.
protected void	initApplicationContext()	Invoked on startup.
protected boolean	isCacheTemplate()	Return whether the Velocity template should be cached.
protected void	mergeTemplate(org.apache.velocity.Template t, org.apache.velocity.context.Context context, javax.servlet.http.HttpServletResponse response)	Merge the template with the context.
protected void	renderMergedTemplateModel(Map<String,Object> model, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)	Process the model map by merging it with the Velocity template.
void	setCacheTemplate(boolean flag)	Set whether the Velocity template should be cached (default is "false").
void	setEncoding(String enc)	Set the encoding of the Velocity template file.
void	setVelocityEngine(org.apache.velocity.app.VelocityEngine engine)	Set the VelocityEngine to be used by this view.

Methods inherited from class org.springframework.web.servlet.view.AbstractTemplateView

applyContentType, renderMergedOutputModel, renderMergedTemplateModel, setAllowRequestOverride, setAllowSessionOverride, setExposeRequestAttributes, setExposeSessionAttributes, setExposeSpringMacroHelpers

Methods inherited from class org.springframework.web.servlet.view.AbstractUrlBasedView

afterPropertiesSet, getUrl, isUrlRequired, setUrl, toString

Methods inherited from class org.springframework.web.servlet.view.AbstractView

addStaticAttribute, createMergedOutputModel, createRequestContext, createTemporaryOutputStream, exposeModelAsRequestAttributes, formatViewName, generatesDownloadContent, getAttributesMap, getBeanName, getContentType, getRequestContextAttribute, getRequestToExpose, getStaticAttributes, isExposePathVariables, prepareResponse, render, setAttributes, setAttributesCSV, setAttributesMap, setBeanName, setContentType, setExposeContextBeansAsAttributes, setExposedContextBeanNames, setExposePathVariables, setRequestContextAttribute, setResponseContentType, writeToResponse

Methods inherited from class org.springframework.web.context.support.WebApplicationObjectSupport

getServletContext, getTempDir, getWebApplicationContext, initApplicationContext, initServletContext, isContextRequired, setServletContext

Methods inherited from class org.springframework.context.support.ApplicationObjectSupport

getApplicationContext, getMessageSourceAccessor, obtainApplicationContext, requiredContextClass, setApplicationContext

Methods inherited from class java.lang.Object

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

Field Detail

encoding

@Nullable
private String encoding

Template encoding.

cacheTemplate

private boolean cacheTemplate

Caching flag.

velocityEngine

@Nullable
private org.apache.velocity.app.VelocityEngine velocityEngine

Velocity engine.

template

@Nullable
private org.apache.velocity.Template template

The template.

Constructor Detail

VelocityView

public VelocityView()

Method Detail

setEncoding

public void setEncoding(@Nullable
                        String enc)

Set the encoding of the Velocity template file.

Default is determined by the VelocityEngine: "ISO-8859-1" if not specified otherwise. Specify the encoding in the VelocityEngine rather than per template if all your templates share a common encoding.

Parameters:

enc - encoding

getEncoding

@Nullable
protected String getEncoding()

Return the encoding for the Velocity template.

Returns:

encoding

setCacheTemplate

public void setCacheTemplate(boolean flag)

Set whether the Velocity template should be cached (default is "false").

It should normally be true in production, but setting this to false enables us to modify Velocity templates without restarting the application (similar to JSPs).

Note that this is a minor optimization only, as Velocity itself caches templates in a modification-aware fashion.

Parameters:

flag - flag to set

isCacheTemplate

protected boolean isCacheTemplate()

Return whether the Velocity template should be cached.

Returns:

whether template should be cached

setVelocityEngine

public void setVelocityEngine(@Nullable
                              org.apache.velocity.app.VelocityEngine engine)

Set the VelocityEngine to be used by this view.

If this is not set, the default lookup will occur: A single VelocityConfig is expected in the current web application context, with any bean name.

Parameters:

engine - velocity engine

getVelocityEngine

@Nullable
protected org.apache.velocity.app.VelocityEngine getVelocityEngine()

Return the VelocityEngine used by this view.

Returns:

engine

initApplicationContext

protected void initApplicationContext()
                               throws BeansException

Invoked on startup. Looks for a single VelocityConfig bean to find the relevant VelocityEngine for this factory.

Overrides:

initApplicationContext in class ApplicationObjectSupport

Throws:

BeansException

autodetectVelocityEngine

@Nonnull
protected org.apache.velocity.app.VelocityEngine autodetectVelocityEngine()
                                                                   throws BeansException

Autodetect a VelocityEngine via the ApplicationContext.

Called if no explicit VelocityEngine has been specified.

Returns:

the VelocityEngine to use

Throws:

BeansException - if no VelocityEngine could be found

checkResource

public boolean checkResource(@Nullable
                             Locale locale)
                      throws Exception

Check that the Velocity template used for this view exists and is valid.

Can be overridden to customize the behavior, for example in case of multiple templates to be rendered into a single view.

Overrides:

checkResource in class AbstractUrlBasedView

Throws:

Exception

renderMergedTemplateModel

protected void renderMergedTemplateModel(Map<String,Object> model,
                                         javax.servlet.http.HttpServletRequest request,
                                         javax.servlet.http.HttpServletResponse response)
                                  throws Exception

Process the model map by merging it with the Velocity template.

Output is directed to the servlet response. This method can be overridden if custom behavior is needed.

Throws:

Exception

createVelocityContext

protected org.apache.velocity.context.Context createVelocityContext(@Nullable
                                                                    Map<String,Object> model,
                                                                    @Nonnull
                                                                    javax.servlet.http.HttpServletRequest request,
                                                                    @Nonnull
                                                                    javax.servlet.http.HttpServletResponse response)
                                                             throws Exception

Create a Velocity Context instance for the given model, to be passed to the template for merging.

The default implementation delegates to createVelocityContext(Map). Can be overridden for a special context class, for example ChainedContext which is part of the view package of Velocity Tools. ChainedContext is needed for initialization of ViewTool instances.

Parameters:

model - the model Map, containing the model attributes to be exposed to the view

request - current HTTP request

response - current HTTP response

Returns:

the Velocity Context

Throws:

Exception - if there's a fatal error while creating the context

createVelocityContext

protected org.apache.velocity.context.Context createVelocityContext(Map<String,Object> model)
                                                             throws Exception

Create a Velocity Context instance for the given model, to be passed to the template for merging.

Default implementation creates an instance of Velocity's VelocityContext implementation class.

Parameters:

model - the model Map, containing the model attributes to be exposed to the view

Returns:

the Velocity Context

Throws:

Exception - if there's a fatal error while creating the context

doRender

protected void doRender(org.apache.velocity.context.Context context,
                        javax.servlet.http.HttpServletResponse response)
                 throws Exception

Render the Velocity view to the given response, using the given Velocity context which contains the complete template model to use.

The default implementation renders the template specified by the "url" bean property, retrieved via getTemplate. It delegates to the mergeTemplate method to merge the template instance with the given Velocity context.

Can be overridden to customize the behavior, for example to render multiple templates into a single view.

Parameters:

context - the Velocity context to use for rendering

response - servlet response (use this to get the OutputStream or Writer)

Throws:

Exception - if thrown by Velocity

getTemplate

protected org.apache.velocity.Template getTemplate()
                                            throws Exception

Retrieve the Velocity template to be rendered by this view.

By default, the template specified by the "url" bean property will be retrieved: either returning a cached template instance or loading a fresh instance (according to the "cacheTemplate" bean property)

Returns:

the Velocity template to render

Throws:

Exception - if thrown by Velocity

getTemplate

protected org.apache.velocity.Template getTemplate(String name)
                                            throws Exception

Retrieve the Velocity template specified by the given name, using the encoding specified by the "encoding" bean property.

Can be called by subclasses to retrieve a specific template, for example to render multiple templates into a single view.

Parameters:

name - the file name of the desired template

Returns:

the Velocity template

Throws:

Exception - if thrown by Velocity

mergeTemplate

protected void mergeTemplate(org.apache.velocity.Template t,
                             org.apache.velocity.context.Context context,
                             @Nonnull
                             javax.servlet.http.HttpServletResponse response)
                      throws Exception

Merge the template with the context.

Parameters:

t - the template to merge

context - the Velocity context to use for rendering

response - servlet response (use this to get the OutputStream or Writer)

Throws:

Exception - if thrown by Velocity