Package org.springframework.web.servlet.view.freemarker

Class FreeMarkerView

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

org.springframework.web.servlet.view.freemarker.FreeMarkerView

All Implemented Interfaces:

Aware, BeanNameAware, InitializingBean, ApplicationContextAware, ServletContextAware, View

public class FreeMarkerView
extends AbstractTemplateView

View using the FreeMarker template engine.

Exposes the following configuration properties:

• url: the location of the FreeMarker template relative to the FreeMarker template context (directory).
• encoding: the encoding used to decode byte sequences to character sequences when reading the FreeMarker template file. Default is determined by the FreeMarker Configuration.
• contentType: the content type of the rendered response. Defaults to "text/html;charset=ISO-8859-1" but should typically be set to a value that corresponds to the actual generated content type (see note below).

Depends on a single FreeMarkerConfig object such as FreeMarkerConfigurer being accessible in the current web application context. Alternatively the FreeMarker Configuration can be set directly via setConfiguration(freemarker.template.Configuration).

Note: To ensure that the correct encoding is used when rendering the response, set the content type with an appropriate charset attribute — for example, "text/html;charset=UTF-8". When using FreeMarkerViewResolver to create the view for you, set the content type directly in the FreeMarkerViewResolver.

Note: Spring's FreeMarker support requires FreeMarker 2.3.21 or higher. As of Spring Framework 6.0, FreeMarker templates are rendered in a minimal fashion without JSP support, just exposing request attributes in addition to the MVC-provided model map for alignment with common Servlet resources.

Since:

03.03.2004

Author:

Darren Davison, Juergen Hoeller, Sam Brannen

See Also:

• AbstractUrlBasedView.setUrl(java.lang.String)
• AbstractTemplateView.setExposeSpringMacroHelpers(boolean)
• setEncoding(java.lang.String)
• setConfiguration(freemarker.template.Configuration)
• FreeMarkerConfig
• FreeMarkerConfigurer

Field Summary

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
FreeMarkerView()

Method Summary

Modifier and Type	Method	Description
protected FreeMarkerConfig	autodetectConfiguration()	Autodetect a FreeMarkerConfig object via the ApplicationContext.
protected freemarker.template.SimpleHash	buildTemplateModel(Map<String,Object> model, HttpServletRequest request, HttpServletResponse response)	Build a FreeMarker template model for the given model Map.
boolean	checkResource(Locale locale)	Check that the FreeMarker template used for this view exists and is valid.
protected void	doRender(Map<String,Object> model, HttpServletRequest request, HttpServletResponse response)	Render the FreeMarker view to the given response, using the given model map which contains the complete template model to use.
protected void	exposeHelpers(Map<String,Object> model, HttpServletRequest request)	Expose helpers unique to each rendering operation.
protected freemarker.template.Configuration	getConfiguration()	Return the FreeMarker Configuration used by this view.
protected String	getEncoding()	Get the encoding used to decode byte sequences to character sequences when reading the FreeMarker template file for this view, or null to signal that the FreeMarker Configuration should be used to determine the encoding.
protected freemarker.template.ObjectWrapper	getObjectWrapper()	Return the configured FreeMarker ObjectWrapper, or the default wrapper if none specified.
protected freemarker.template.Template	getTemplate(String name, Locale locale)	Retrieve the FreeMarker Template for the specified name and locale, using the configured encoding if set.
protected freemarker.template.Template	getTemplate(Locale locale)	Retrieve the FreeMarker Template for the given locale, to be rendered by this view.
protected void	initServletContext(ServletContext servletContext)	Invoked on startup.
protected freemarker.template.Configuration	obtainConfiguration()	Obtain the FreeMarker Configuration for actual use.
protected void	processTemplate(freemarker.template.Template template, freemarker.template.SimpleHash model, HttpServletResponse response)	Process the FreeMarker template to the servlet response.
protected void	renderMergedTemplateModel(Map<String,Object> model, HttpServletRequest request, HttpServletResponse response)	Process the model map by merging it with the FreeMarker template.
void	setConfiguration(freemarker.template.Configuration configuration)	Set the FreeMarker Configuration to be used by this view.
void	setEncoding(String encoding)	Set the encoding used to decode byte sequences to character sequences when reading the FreeMarker template file for this view.

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

applyContentType, renderMergedOutputModel, 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, isContextRequired, setServletContext

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

getApplicationContext, getMessageSourceAccessor, initApplicationContext, obtainApplicationContext, requiredContextClass, setApplicationContext

Methods inherited from class java.lang.Object

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

Constructor Details

FreeMarkerView

public FreeMarkerView()

Method Details

setEncoding

public void setEncoding(@Nullable
 String encoding)

Set the encoding used to decode byte sequences to character sequences when reading the FreeMarker template file for this view.

Defaults to null to signal that the FreeMarker Configuration should be used to determine the encoding.

A non-null encoding will override the default encoding determined by the FreeMarker Configuration.

If the encoding is not explicitly set here or in the FreeMarker Configuration, FreeMarker will read template files using the platform file encoding (defined by the JVM system property file.encoding) or "utf-8" if the platform file encoding is undefined.

It's recommended to specify the encoding in the FreeMarker Configuration rather than per template if all your templates share a common encoding.

Note that the specified or default encoding is not used for template rendering. Instead, an explicit encoding must be specified for the rendering process. See the note in the class-level documentation for details.

See Also:

• Configuration.setDefaultEncoding(java.lang.String)
• getEncoding()
• AbstractView.setContentType(String)

getEncoding

@Nullable
protected String getEncoding()

Get the encoding used to decode byte sequences to character sequences when reading the FreeMarker template file for this view, or null to signal that the FreeMarker Configuration should be used to determine the encoding.

See Also:

• setEncoding(String)

setConfiguration

public void setConfiguration(@Nullable
 freemarker.template.Configuration configuration)

Set the FreeMarker Configuration to be used by this view.

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

getConfiguration

@Nullable
protected freemarker.template.Configuration getConfiguration()

Return the FreeMarker Configuration used by this view.

obtainConfiguration

protected freemarker.template.Configuration obtainConfiguration()

Obtain the FreeMarker Configuration for actual use.

Returns:

the FreeMarker configuration (never null)

Throws:

IllegalStateException - in case of no Configuration object set

Since:

5.0

initServletContext

protected void initServletContext(ServletContext servletContext)
                           throws BeansException

Invoked on startup. Looks for a single FreeMarkerConfig bean to find the relevant Configuration for this view.

Checks that the template for the default Locale can be found: FreeMarker will check non-Locale-specific templates if a locale-specific one is not found.

Overrides:

initServletContext in class WebApplicationObjectSupport

Parameters:

servletContext - the ServletContext that this application object runs in (never null)

Throws:

BeansException

See Also:

• TemplateCache.getTemplate(java.lang.String, java.util.Locale, java.lang.Object, java.lang.String, boolean)

autodetectConfiguration

protected FreeMarkerConfig autodetectConfiguration()
                                            throws BeansException

Autodetect a FreeMarkerConfig object via the ApplicationContext.

Returns:

the FreeMarkerConfig instance to use for FreeMarkerViews

Throws:

BeansException - if no FreeMarkerConfig bean could be found

See Also:

• ApplicationObjectSupport.getApplicationContext()
• setConfiguration(freemarker.template.Configuration)

getObjectWrapper

protected freemarker.template.ObjectWrapper getObjectWrapper()

Return the configured FreeMarker ObjectWrapper, or the default wrapper if none specified.

See Also:

• Configurable.getObjectWrapper()

checkResource

public boolean checkResource(Locale locale)
                      throws Exception

Check that the FreeMarker 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

Parameters:

locale - the desired Locale that we're looking for

Returns:

true if the resource exists (or is assumed to exist); false if we know that it does not exist

Throws:

Exception - if the resource exists but is invalid (e.g. could not be parsed)

renderMergedTemplateModel

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

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

Output is directed to the servlet response.

This method can be overridden if custom behavior is needed.

Specified by:

renderMergedTemplateModel in class AbstractTemplateView

Parameters:

model - combined output Map, with request attributes and session attributes merged into it if required

request - current HTTP request

response - current HTTP response

Throws:

Exception - if rendering failed

exposeHelpers

protected void exposeHelpers(Map<String,Object> model,
 HttpServletRequest request)
                      throws Exception

Expose helpers unique to each rendering operation. This is necessary so that different rendering operations can't overwrite each other's formats etc.

Called by renderMergedTemplateModel. The default implementation is empty. This method can be overridden to add custom helpers to the model.

Parameters:

model - the model that will be passed to the template at merge time

request - current HTTP request

Throws:

Exception - if there's a fatal error while we're adding information to the context

See Also:

• renderMergedTemplateModel(java.util.Map<java.lang.String, java.lang.Object>, jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse)

doRender

protected void doRender(Map<String,Object> model,
 HttpServletRequest request,
 HttpServletResponse response)
                 throws Exception

Render the FreeMarker view to the given response, using the given model map 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 processTemplate method to merge the template instance with the given template model.

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

Parameters:

model - the model to use for rendering

request - current HTTP request

response - current servlet response

Throws:

IOException - if the template file could not be retrieved

Exception - if rendering failed

See Also:

• AbstractUrlBasedView.setUrl(java.lang.String)
• RequestContextUtils.getLocale(jakarta.servlet.http.HttpServletRequest)
• getTemplate(java.util.Locale)
• processTemplate(freemarker.template.Template, freemarker.template.SimpleHash, jakarta.servlet.http.HttpServletResponse)
• FreemarkerServlet

buildTemplateModel

protected freemarker.template.SimpleHash buildTemplateModel(Map<String,Object> model,
 HttpServletRequest request,
 HttpServletResponse response)

Build a FreeMarker template model for the given model Map.

The default implementation builds a SimpleHash for the given MVC model with an additional fallback to request attributes.

Parameters:

model - the model to use for rendering

request - current HTTP request

response - current servlet response

Returns:

the FreeMarker template model, as a SimpleHash or subclass thereof

getTemplate

protected freemarker.template.Template getTemplate(Locale locale)
                                            throws IOException

Retrieve the FreeMarker Template for the given locale, to be rendered by this view.

By default, the template specified by the "url" bean property will be retrieved.

Parameters:

locale - the current locale

Returns:

the FreeMarker Template to render

Throws:

IOException - if the template file could not be retrieved

See Also:

• AbstractUrlBasedView.setUrl(java.lang.String)
• getTemplate(String, java.util.Locale)

getTemplate

protected freemarker.template.Template getTemplate(String name,
 Locale locale)
                                            throws IOException

Retrieve the FreeMarker Template for the specified name and locale, using the configured encoding if set.

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

locale - the current locale

Returns:

the FreeMarker template

Throws:

IOException - if the template file could not be retrieved

See Also:

• setEncoding(String)

processTemplate

protected void processTemplate(freemarker.template.Template template,
 freemarker.template.SimpleHash model,
 HttpServletResponse response)
                        throws IOException,
freemarker.template.TemplateException

Process the FreeMarker template to the servlet response.

Can be overridden to customize the behavior.

Parameters:

template - the template to process

model - the model for the template

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

Throws:

IOException - if the template file could not be retrieved

freemarker.template.TemplateException - if thrown by FreeMarker

See Also:

• Template.process(Object, java.io.Writer)