Module net.shibboleth.ext.spring

Package net.shibboleth.ext.spring.velocity

Class VelocityEngineFactory

java.lang.Object

net.shibboleth.ext.spring.velocity.VelocityEngineFactory

Direct Known Subclasses:

VelocityConfigurer, VelocityEngineFactoryBean

public class VelocityEngineFactory
extends Object

Factory that configures a VelocityEngine. Can be used standalone, but typically you will either use VelocityEngineFactoryBean for preparing a VelocityEngine as bean reference, or VelocityConfigurer for web views.

The optional "configLocation" property sets the location of the Velocity properties file, within the current application. Velocity properties can be overridden via "velocityProperties", or even completely specified locally, avoiding the need for an external properties file.

The "resourceLoaderPath" property can be used to specify the Velocity resource loader path via Spring's Resource abstraction, possibly relative to the Spring application context.

The simplest way to use this class is to specify a "resourceLoaderPath"; the VelocityEngine typically then does not need any further configuration.

Since:

6.0.0

See Also:

setConfigLocation(org.springframework.core.io.Resource), setVelocityProperties(java.util.Properties), setResourceLoaderPath(java.lang.String), createVelocityEngine(), VelocityEngineFactoryBean, VelocityConfigurer, VelocityEngine

Field Summary

Fields

Modifier and Type	Field	Description
private Resource	configLocation	Source of configuration.
private org.slf4j.Logger	log	Class logger.
private boolean	preferFileSystemAccess	Whether to favor file system lookup first.
private ResourceLoader	resourceLoader	Resource loader.
private String	resourceLoaderPath	Path to load resources from.
private Map<String,Object>	velocityProperties	Configuration properties.

Constructor Summary

Constructors

Constructor	Description
VelocityEngineFactory()	Constructor.

Method Summary

Modifier and Type	Method	Description
org.apache.velocity.app.VelocityEngine	createVelocityEngine()	Prepare the VelocityEngine instance and return it.
protected void	initSpringResourceLoader(org.apache.velocity.app.VelocityEngine velocityEngine, String path)	Initialize a SpringResourceLoader for the given VelocityEngine.
protected void	initVelocityResourceLoader(org.apache.velocity.app.VelocityEngine velocityEngine, String loaderPath)	Initialize a Velocity resource loader for the given VelocityEngine: either a standard Velocity FileResourceLoader or a SpringResourceLoader.
protected org.apache.velocity.app.VelocityEngine	newVelocityEngine()	Return a new VelocityEngine.
protected void	postProcessVelocityEngine(org.apache.velocity.app.VelocityEngine velocityEngine)	To be implemented by subclasses that want to perform custom post-processing of the VelocityEngine after the FactoryBean performed its default configuration (but before VelocityEngine.init).
void	setConfigLocation(Resource location)	Set the location of the Velocity config file.
void	setPreferFileSystemAccess(boolean flag)	Set whether to prefer file system access for template loading.
void	setResourceLoader(ResourceLoader loader)	Set the Spring ResourceLoader to use for loading Velocity template files.
void	setResourceLoaderPath(String paths)	Set the Velocity resource loader path via a Spring resource location.
void	setVelocityProperties(Properties props)	Set Velocity properties, like "file.resource.loader.path".
void	setVelocityPropertiesMap(Map<String,Object> map)	Set Velocity properties as Map, to allow for non-String values like "ds.resource.loader.instance".

Methods inherited from class java.lang.Object

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

Field Detail

log

@Nonnull
private final org.slf4j.Logger log

Class logger.

configLocation

@Nullable
private Resource configLocation

Source of configuration.

velocityProperties

@Nonnull
private final Map<String,Object> velocityProperties

Configuration properties.

resourceLoaderPath

@Nullable
private String resourceLoaderPath

Path to load resources from.

resourceLoader

@Nullable
private ResourceLoader resourceLoader

Resource loader.

preferFileSystemAccess

private boolean preferFileSystemAccess

Whether to favor file system lookup first.

Constructor Detail

VelocityEngineFactory

public VelocityEngineFactory()

Constructor.

Method Detail

setConfigLocation

public void setConfigLocation(@Nullable
                              Resource location)

Set the location of the Velocity config file.

Alternatively, you can specify all properties locally.

Parameters:

location - configuration resource

See Also:

setVelocityProperties(java.util.Properties), setResourceLoaderPath(java.lang.String)

setVelocityProperties

public void setVelocityProperties(@Nullable
                                  Properties props)

Set Velocity properties, like "file.resource.loader.path".

Can be used to override values in a Velocity config file, or to specify all necessary properties locally.

Note that the Velocity resource loader path also be set to any Spring resource location via the "resourceLoaderPath" property. Setting it here is just necessary when using a non-file-based resource loader.

Parameters:

props - additional properties

See Also:

setVelocityPropertiesMap(java.util.Map<java.lang.String, java.lang.Object>), setConfigLocation(org.springframework.core.io.Resource), setResourceLoaderPath(java.lang.String)

setVelocityPropertiesMap

public void setVelocityPropertiesMap(@Nullable
                                     Map<String,Object> map)

Set Velocity properties as Map, to allow for non-String values like "ds.resource.loader.instance".

Parameters:

map - properties as map

See Also:

setVelocityProperties(java.util.Properties)

setResourceLoaderPath

public void setResourceLoaderPath(@Nullable
                                  String paths)

Set the Velocity resource loader path via a Spring resource location.

Accepts multiple locations in Velocity's comma-separated path style.

When populated via a String, standard URLs like "file:" and "classpath:" pseudo URLs are supported, as understood by ResourceLoader. Allows for relative paths when running in an ApplicationContext.

Will define a path for the default Velocity resource loader with the name "file". If the specified resource cannot be resolved to a java.io.File, a generic SpringResourceLoader will be used under the name "spring", without modification detection.

Note that resource caching will be enabled in any case. With the file resource loader, the last-modified timestamp will be checked on access to detect changes. With SpringResourceLoader, the resource will be cached forever (for example for class path resources).

To specify a modification check interval for files, use Velocity's standard "file.resource.loader.modificationCheckInterval" property. By default, the file timestamp is checked on every access (which is surprisingly fast). Of course, this just applies when loading resources from the file system.

To enforce the use of SpringResourceLoader, i.e. to not resolve a path as file system resource in any case, turn off the "preferFileSystemAccess" flag. See the latter's javadoc for details.

Parameters:

paths - comma-separated paths

See Also:

setResourceLoader(org.springframework.core.io.ResourceLoader), setVelocityProperties(java.util.Properties), setPreferFileSystemAccess(boolean), SpringResourceLoader, FileResourceLoader

setResourceLoader

public void setResourceLoader(@Nullable
                              ResourceLoader loader)

Set the Spring ResourceLoader to use for loading Velocity template files.

The default is DefaultResourceLoader. Will get overridden by the ApplicationContext if running in a context.

Parameters:

loader - resource loader

See Also:

DefaultResourceLoader, ApplicationContext

setPreferFileSystemAccess

public void setPreferFileSystemAccess(boolean flag)

Set whether to prefer file system access for template loading.

File system access enables hot detection of template changes.

If this is enabled, VelocityEngineFactory will try to resolve the specified "resourceLoaderPath" as file system resource (which will work for expanded class path resources and ServletContext resources too).

Default is "true". Turn this off to always load via SpringResourceLoader (i.e. as stream, without hot detection of template changes), which might be necessary if some of your templates reside in an expanded classes directory while others reside in jar files.

Parameters:

flag - flag to set

See Also:

setResourceLoaderPath(java.lang.String)

createVelocityEngine

@Nonnull
public org.apache.velocity.app.VelocityEngine createVelocityEngine()
                                                            throws IOException,
                                                                   org.apache.velocity.exception.VelocityException

Prepare the VelocityEngine instance and return it.

Returns:

the VelocityEngine instance

Throws:

IOException - if the config file wasn't found

org.apache.velocity.exception.VelocityException - on Velocity initialization failure

newVelocityEngine

@Nonnull
protected org.apache.velocity.app.VelocityEngine newVelocityEngine()
                                                            throws IOException,
                                                                   org.apache.velocity.exception.VelocityException

Return a new VelocityEngine.

Subclasses can override this for custom initialization, or for using a mock object for testing.

Called by createVelocityEngine().

Returns:

the VelocityEngine instance

Throws:

IOException - if a config file wasn't found

org.apache.velocity.exception.VelocityException - on Velocity initialization failure

See Also:

createVelocityEngine()

initVelocityResourceLoader

protected void initVelocityResourceLoader(@Nonnull
                                          org.apache.velocity.app.VelocityEngine velocityEngine,
                                          @Nullable
                                          String loaderPath)

Initialize a Velocity resource loader for the given VelocityEngine: either a standard Velocity FileResourceLoader or a SpringResourceLoader.

Parameters:

velocityEngine - the VelocityEngine to configure

loaderPath - the path to load Velocity resources from

See Also:

FileResourceLoader, SpringResourceLoader, initSpringResourceLoader(org.apache.velocity.app.VelocityEngine, java.lang.String), createVelocityEngine()

initSpringResourceLoader

protected void initSpringResourceLoader(@Nonnull
                                        org.apache.velocity.app.VelocityEngine velocityEngine,
                                        @Nullable
                                        String path)

Initialize a SpringResourceLoader for the given VelocityEngine.

Called by initVelocityResourceLoader.

Parameters:

velocityEngine - the VelocityEngine to configure

path - the path to load Velocity resources from

See Also:

SpringResourceLoader, initVelocityResourceLoader(org.apache.velocity.app.VelocityEngine, java.lang.String)

postProcessVelocityEngine

protected void postProcessVelocityEngine(@Nonnull
                                         org.apache.velocity.app.VelocityEngine velocityEngine)
                                  throws IOException,
                                         org.apache.velocity.exception.VelocityException

To be implemented by subclasses that want to perform custom post-processing of the VelocityEngine after the FactoryBean performed its default configuration (but before VelocityEngine.init).

Parameters:

velocityEngine - the current VelocityEngine

Throws:

IOException - if a config file wasn't found

org.apache.velocity.exception.VelocityException - on Velocity initialization failure

See Also:

createVelocityEngine(), VelocityEngine.init()