org.apache.velocity.runtime
Class RuntimeSingleton

java.lang.Object
  org.apache.velocity.runtime.RuntimeSingleton

All Implemented Interfaces:

RuntimeConstants

public class RuntimeSingleton
extends Object
implements RuntimeConstants

This is the Runtime system for Velocity. It is the single access point for all functionality in Velocity. It adheres to the mediator pattern and is the only structure that developers need to be familiar with in order to get Velocity to perform. The Runtime will also cooperate with external systems like Turbine. Runtime properties can set and then the Runtime is initialized. Turbine for example knows where the templates are to be loaded from, and where the velocity log file should be placed. So in the case of Velocity cooperating with Turbine the code might look something like the following:

 RuntimeSingleton.setProperty(RuntimeConstants.FILE_RESOURCE_LOADER_PATH, templatePath);
 RuntimeSingleton.setProperty(RuntimeConstants.RUNTIME_LOG, pathToVelocityLog);
 RuntimeSingleton.init();
 

 -----------------------------------------------------------------------
 N O T E S  O N  R U N T I M E  I N I T I A L I Z A T I O N
 -----------------------------------------------------------------------
 RuntimeSingleton.init()
 
 If Runtime.init() is called by itself the Runtime will
 initialize with a set of default values.
 -----------------------------------------------------------------------
 RuntimeSingleton.init(String/Properties)

 In this case the default velocity properties are layed down
 first to provide a solid base, then any properties provided
 in the given properties object will override the corresponding
 default property.
 -----------------------------------------------------------------------
 

Version:

$Id: RuntimeSingleton.java 191743 2005-06-21 23:22:20Z dlr $

Author:

Jason van Zyl, Jeff Bowden, Geir Magusson Jr., Daniel Rall

See Also:

RuntimeInstance

Field Summary

Fields inherited from interface org.apache.velocity.runtime.RuntimeConstants

COUNTER_INITIAL_VALUE, COUNTER_NAME, DEFAULT_RUNTIME_DIRECTIVES, DEFAULT_RUNTIME_PROPERTIES, ENCODING_DEFAULT, ERRORMSG_END, ERRORMSG_START, FILE_RESOURCE_LOADER_CACHE, FILE_RESOURCE_LOADER_PATH, INPUT_ENCODING, INTERPOLATE_STRINGLITERALS, MAX_NUMBER_LOOPS, NUMBER_OF_PARSERS, OUTPUT_ENCODING, PARSE_DIRECTIVE_MAXDEPTH, PARSER_POOL_SIZE, RESOURCE_LOADER, RESOURCE_MANAGER_CACHE_CLASS, RESOURCE_MANAGER_CLASS, RESOURCE_MANAGER_DEFAULTCACHE_SIZE, RESOURCE_MANAGER_LOGWHENFOUND, RUNTIME_LOG_REFERENCE_LOG_INVALID, UBERSPECT_CLASSNAME, VM_CONTEXT_LOCALSCOPE, VM_LIBRARY, VM_LIBRARY_AUTORELOAD, VM_LIBRARY_DEFAULT, VM_MESSAGES_ON, VM_PERM_ALLOW_INLINE, VM_PERM_ALLOW_INLINE_REPLACE_GLOBAL, VM_PERM_INLINE_LOCAL

Constructor Summary

RuntimeSingleton()

Method Summary

static void	addProperty(String key, Object value) Add a property to the configuration.
static boolean	addVelocimacro(String name, String macro, String[] argArray, String sourceTemplate, int line, int column) Adds a new Velocimacro.
static void	clearProperty(String key) Clear the values pertaining to a particular property.
static boolean	dumpVMNamespace(String namespace) tells the vmFactory to dump the specified namespace.
static Object	getApplicationAttribute(Object key)
static boolean	getBoolean(String key, boolean def) Boolean property accessor method to hide the configuration implementation.
static org.apache.commons.collections.ExtendedProperties	getConfiguration() Return the velocity runtime configuration object.
static ContentResource	getContent(String name) Returns a static content resource from the resource manager.
static ContentResource	getContent(String name, String encoding) Returns a static content resource from the resource manager.
static int	getInt(String key) Int property accessor method to hide the configuration implementation.
static int	getInt(String key, int defaultValue) Int property accessor method to hide the configuration implementation.
static Introspector	getIntrospector() Return the Introspector for this RuntimeInstance
static String	getLoaderNameForResource(String resourceName) Determines is a template exists, and returns name of the loader that provides it.
static Object	getProperty(String key) Allows an external caller to get a property.
static RuntimeInstance	getRuntimeInstance() Deprecated. Use getRuntimeServices() instead.
static RuntimeServices	getRuntimeServices()
static String	getString(String key) String property accessor method to hide the configuration implementation
static String	getString(String key, String defaultValue) String property accessor method with default to hide the configuration implementation.
static Template	getTemplate(String name) Returns a Template from the resource manager.
static Template	getTemplate(String name, String encoding) Returns a Template from the resource manager
static Uberspect	getUberspect()
static Directive	getVelocimacro(String vmName, String templateName) Returns the appropriate VelocimacroProxy object if strVMname is a valid current Velocimacro.
static void	init() This is the primary initialization method in the Velocity Runtime.
static void	init(Properties p) Initialize the Velocity Runtime with a Properties object.
static void	init(String configurationFile) Initialize the Velocity Runtime with the name of ExtendedProperties object.
static boolean	isVelocimacro(String vmName, String templateName) Checks to see if a VM exists
static SimpleNode	parse(Reader reader, String templateName) Parse the input and return the root of AST node structure.
static SimpleNode	parse(Reader reader, String templateName, boolean dumpNamespace) Parse the input and return the root of the AST node structure.
static void	setConfiguration(org.apache.commons.collections.ExtendedProperties configuration) Allow an external system to set an ExtendedProperties object to use.
static void	setProperty(String key, Object value) Allows an external system to set a property in the Velocity Runtime.

Methods inherited from class java.lang.Object

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

Constructor Detail

RuntimeSingleton

public RuntimeSingleton()

Method Detail

init

public static void init()
                 throws Exception

This is the primary initialization method in the Velocity Runtime. The systems that are setup/initialized here are as follows:

• Logging System
• ResourceManager
• Parser Pool
• Global Cache
• Static Content Include System
• Velocimacro System

Throws:

Exception

getRuntimeServices

public static RuntimeServices getRuntimeServices()

Returns:

The RuntimeInstance used by this wrapper.

setProperty

public static void setProperty(String key,
                               Object value)

Allows an external system to set a property in the Velocity Runtime.

Parameters:

key - property key

value - property value

setConfiguration

public static void setConfiguration(org.apache.commons.collections.ExtendedProperties configuration)

Allow an external system to set an ExtendedProperties object to use. This is useful where the external system also uses the ExtendedProperties class and the velocity configuration is a subset of parent application's configuration. This is the case with Turbine.

Parameters:

configuration -

addProperty

public static void addProperty(String key,
                               Object value)

Add a property to the configuration. If it already exists then the value stated here will be added to the configuration entry. For example, if resource.loader = file is already present in the configuration and you addProperty("resource.loader", "classpath") Then you will end up with a Vector like the following: ["file", "classpath"]

Parameters:

key -

value -

clearProperty

public static void clearProperty(String key)

Clear the values pertaining to a particular property.

Parameters:

key - key of property to clear

getProperty

public static Object getProperty(String key)

Allows an external caller to get a property. The calling routine is required to know the type, as this routine will return an Object, as that is what properties can be.

Parameters:

key - property to return

init

public static void init(Properties p)
                 throws Exception

Initialize the Velocity Runtime with a Properties object.

Parameters:

p -

Throws:

Exception

init

public static void init(String configurationFile)
                 throws Exception

Initialize the Velocity Runtime with the name of ExtendedProperties object.

Parameters:

configurationFile -

Throws:

Exception

parse

public static SimpleNode parse(Reader reader,
                               String templateName)
                        throws ParseException

Parse the input and return the root of AST node structure.

In the event that it runs out of parsers in the pool, it will create and let them be GC'd dynamically, logging that it has to do that. This is considered an exceptional condition. It is expected that the user will set the PARSER_POOL_SIZE property appropriately for their application. We will revisit this.

Parameters:

reader - inputstream retrieved by a resource loader

templateName - name of the template being parsed

Throws:

ParseException

parse

public static SimpleNode parse(Reader reader,
                               String templateName,
                               boolean dumpNamespace)
                        throws ParseException

Parse the input and return the root of the AST node structure.

Parameters:

reader - inputstream retrieved by a resource loader

templateName - name of the template being parsed

dumpNamespace - flag to dump the Velocimacro namespace for this template

Throws:

ParseException

getTemplate

public static Template getTemplate(String name)
                            throws ResourceNotFoundException,
                                   ParseErrorException,
                                   Exception

Returns a Template from the resource manager. This method assumes that the character encoding of the template is set by the input.encoding property. The default is "ISO-8859-1"

Parameters:

name - The file name of the desired template.

Returns:

The template.

Throws:

ResourceNotFoundException - if template not found from any available source.

ParseErrorException - if template cannot be parsed due to syntax (or other) error.

Exception - if an error occurs in template initialization

getTemplate

public static Template getTemplate(String name,
                                   String encoding)
                            throws ResourceNotFoundException,
                                   ParseErrorException,
                                   Exception

Returns a Template from the resource manager

Parameters:

name - The name of the desired template.

encoding - Character encoding of the template

Returns:

The template.

Throws:

ResourceNotFoundException - if template not found from any available source.

ParseErrorException - if template cannot be parsed due to syntax (or other) error.

Exception - if an error occurs in template initialization

getContent

public static ContentResource getContent(String name)
                                  throws ResourceNotFoundException,
                                         ParseErrorException,
                                         Exception

Returns a static content resource from the resource manager. Uses the current value if INPUT_ENCODING as the character encoding.

Parameters:

name - Name of content resource to get

Returns:

parsed ContentResource object ready for use

Throws:

ResourceNotFoundException - if template not found from any available source.

ParseErrorException

Exception

getContent

public static ContentResource getContent(String name,
                                         String encoding)
                                  throws ResourceNotFoundException,
                                         ParseErrorException,
                                         Exception

Returns a static content resource from the resource manager.

Parameters:

name - Name of content resource to get

encoding - Character encoding to use

Returns:

parsed ContentResource object ready for use

Throws:

ResourceNotFoundException - if template not found from any available source.

ParseErrorException

Exception

getLoaderNameForResource

public static String getLoaderNameForResource(String resourceName)

Determines is a template exists, and returns name of the loader that provides it. This is a slightly less hokey way to support the Velocity.templateExists() utility method, which was broken when per-template encoding was introduced. We can revisit this.

Parameters:

resourceName - Name of template or content resource

Returns:

class name of loader than can provide it

getString

public static String getString(String key,
                               String defaultValue)

String property accessor method with default to hide the configuration implementation.

Parameters:

key - key property key

defaultValue - default value to return if key not found in resource manager.

Returns:

value of key or default

getVelocimacro

public static Directive getVelocimacro(String vmName,
                                       String templateName)

Returns the appropriate VelocimacroProxy object if strVMname is a valid current Velocimacro.

Parameters:

vmName - Name of velocimacro requested

templateName -

Returns:

VelocimacroProxy

addVelocimacro

public static boolean addVelocimacro(String name,
                                     String macro,
                                     String[] argArray,
                                     String sourceTemplate,
                                     int line,
                                     int column)

Adds a new Velocimacro. Usually called by Macro only while parsing.

Parameters:

name - Name of velocimacro

macro - String form of macro body

argArray - Array of strings, containing the #macro() arguments. the 0th is the name.

Returns:

True if added, false if rejected for some reason (either parameters or permission settings)

isVelocimacro

public static boolean isVelocimacro(String vmName,
                                    String templateName)

Checks to see if a VM exists

Parameters:

vmName - Name of velocimacro

templateName -

Returns:

True if VM by that name exists, false if not

dumpVMNamespace

public static boolean dumpVMNamespace(String namespace)

tells the vmFactory to dump the specified namespace. This is to support clearing the VM list when in inline-VM-local-scope mode

getString

public static String getString(String key)

String property accessor method to hide the configuration implementation

Parameters:

key - property key

Returns:

value of key or null

getInt

public static int getInt(String key)

Int property accessor method to hide the configuration implementation.

Parameters:

key - key property key

Returns:

value

getInt

public static int getInt(String key,
                         int defaultValue)

Int property accessor method to hide the configuration implementation.

Parameters:

key - property key

defaultValue - default value

Returns:

value

getBoolean

public static boolean getBoolean(String key,
                                 boolean def)

Boolean property accessor method to hide the configuration implementation.

Parameters:

key - property key

def - default value if property not found

Returns:

value of key or default value

getConfiguration

public static org.apache.commons.collections.ExtendedProperties getConfiguration()

Return the velocity runtime configuration object.

Returns:

configuration object which houses the velocity runtime properties.

getIntrospector

public static Introspector getIntrospector()

Return the Introspector for this RuntimeInstance

Returns:

Introspector object for this runtime instance

getApplicationAttribute

public static Object getApplicationAttribute(Object key)

See Also:

RuntimeServices.getApplicationAttribute(Object)

getUberspect

public static Uberspect getUberspect()

See Also:

RuntimeServices.getUberspect()

getRuntimeInstance

@Deprecated
public static RuntimeInstance getRuntimeInstance()

Deprecated. Use getRuntimeServices() instead.