org.apache.velocity.runtime
Class RuntimeSingleton

java.lang.Object
  extended by 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 957852 2010-06-25 08:53:22Z apetrelli $
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
DEFAULT_RUNTIME_DIRECTIVES, DEFAULT_RUNTIME_PROPERTIES, DEFINE_DIRECTIVE_MAXDEPTH, ENCODING_DEFAULT, ERRORMSG_END, ERRORMSG_START, EVENTHANDLER_INCLUDE, EVENTHANDLER_INVALIDREFERENCES, EVENTHANDLER_METHODEXCEPTION, EVENTHANDLER_REFERENCEINSERTION, FILE_RESOURCE_LOADER_CACHE, FILE_RESOURCE_LOADER_PATH, INPUT_ENCODING, INTERPOLATE_STRINGLITERALS, INTROSPECTOR_RESTRICT_CLASSES, INTROSPECTOR_RESTRICT_PACKAGES, MAX_NUMBER_LOOPS, NUMBER_OF_PARSERS, OUTPUT_ENCODING, PARSE_DIRECTIVE_MAXDEPTH, PARSER_POOL_CLASS, PARSER_POOL_SIZE, PROVIDE_SCOPE_CONTROL, RESOURCE_LOADER, RESOURCE_MANAGER_CACHE_CLASS, RESOURCE_MANAGER_CLASS, RESOURCE_MANAGER_DEFAULTCACHE_SIZE, RESOURCE_MANAGER_LOGWHENFOUND, RUNTIME_LOG, RUNTIME_LOG_LOGSYSTEM, RUNTIME_LOG_LOGSYSTEM_CLASS, RUNTIME_LOG_REFERENCE_LOG_INVALID, RUNTIME_REFERENCES_STRICT, RUNTIME_REFERENCES_STRICT_ESCAPE, SKIP_INVALID_ITERATOR, STRICT_MATH, UBERSPECT_CLASSNAME, VM_ARGUMENTS_STRICT, VM_BODY_REFERENCE, VM_LIBRARY, VM_LIBRARY_AUTORELOAD, VM_LIBRARY_DEFAULT, VM_MAX_DEPTH, 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, Node macro, List<Macro.MacroArg> macroArgs, String sourceTemplate)
          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)
          Gets the application attribute for the given key
static boolean getBoolean(String key, boolean def)
          Boolean property accessor method to hide the configuration implementation.
static 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.
 EventCartridge getEventCartridge()
          Returns the event handlers for the application.
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 Log getLog()
          Returns a convenient Log instance that wraps the current LogChute.
static Object getProperty(String key)
          Allows an external caller to get a property.
static RuntimeServices getRuntimeServices()
          Returns the RuntimeServices Instance used by this wrapper.
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()
          Returns the Uberspect object for this Instance.
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 isInitialized()
          Returns true if the RuntimeInstance has been successfully initialized.
static boolean isVelocimacro(String vmName, String templateName)
          Checks to see if a VM exists
static void loadDirective(String directiveClass)
          Instantiates and loads the directive with some basic checks.
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 removeDirective(String name)
          Remove a directive.
static void reset()
          Resets the instance, so Velocity can be re-initialized again.
static void setConfiguration(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()
This is the primary initialization method in the Velocity Runtime. The systems that are setup/initialized here are as follows:

See Also:
RuntimeInstance.init()

reset

public static void reset()
Resets the instance, so Velocity can be re-initialized again.

Since:
2.0.0

isInitialized

public static boolean isInitialized()
Returns true if the RuntimeInstance has been successfully initialized.

Returns:
True if the RuntimeInstance has been successfully initialized.
Since:
1.5
See Also:
RuntimeInstance.isInitialized()

getRuntimeServices

public static RuntimeServices getRuntimeServices()
Returns the RuntimeServices Instance used by this wrapper.

Returns:
The RuntimeServices Instance 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
See Also:
RuntimeInstance.setProperty(String, Object)

setConfiguration

public static void setConfiguration(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 -
See Also:
RuntimeInstance.setConfiguration(ExtendedProperties)

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 -
See Also:
RuntimeInstance.addProperty(String, Object)

clearProperty

public static void clearProperty(String key)
Clear the values pertaining to a particular property.

Parameters:
key - of property to clear
See Also:
RuntimeInstance.clearProperty(String)

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
Returns:
Value of the property or null if it does not exist.
See Also:
RuntimeInstance.getProperty(String)

init

public static void init(Properties p)
Initialize the Velocity Runtime with a Properties object.

Parameters:
p -
See Also:
RuntimeInstance.init(Properties)

init

public static void init(String configurationFile)
Initialize the Velocity Runtime with the name of ExtendedProperties object.

Parameters:
configurationFile -
See Also:
RuntimeInstance.init(String)

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 - Reader retrieved by a resource loader
templateName - name of the template being parsed
Returns:
A root node representing the template as an AST tree.
Throws:
ParseException - When the template could not be parsed.
See Also:
RuntimeInstance.parse(Reader, String)

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 - Reader retrieved by a resource loader
templateName - name of the template being parsed
dumpNamespace - flag to dump the Velocimacro namespace for this template
Returns:
A root node representing the template as an AST tree.
Throws:
ParseException - When the template could not be parsed.
See Also:
RuntimeInstance.parse(Reader, String, boolean)

getTemplate

public static Template getTemplate(String name)
                            throws ResourceNotFoundException,
                                   ParseErrorException
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.
See Also:
RuntimeInstance.getTemplate(String)

getTemplate

public static Template getTemplate(String name,
                                   String encoding)
                            throws ResourceNotFoundException,
                                   ParseErrorException
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.
See Also:
RuntimeInstance.getTemplate(String, String)

getContent

public static ContentResource getContent(String name)
                                  throws ResourceNotFoundException,
                                         ParseErrorException
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 - When the template could not be parsed.
See Also:
RuntimeInstance.getContent(String)

getContent

public static ContentResource getContent(String name,
                                         String encoding)
                                  throws ResourceNotFoundException,
                                         ParseErrorException
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 - When the template could not be parsed.
See Also:
RuntimeInstance.getContent(String, String)

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
See Also:
RuntimeInstance.getLoaderNameForResource(String)

getLog

public static Log getLog()
Returns a convenient Log instance that wraps the current LogChute.

Returns:
A convenience Log instance that wraps the current LogChute.
Since:
1.5
See Also:
RuntimeInstance.getLog()

getString

public static String getString(String key,
                               String defaultValue)
String property accessor method with default to hide the configuration implementation.

Parameters:
key - property key
defaultValue - default value to return if key not found in resource manager.
Returns:
value of key or default
See Also:
RuntimeInstance.getString(String, String)

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 - Name of the template that contains the velocimacro.
Returns:
The requested VelocimacroProxy.
See Also:
RuntimeInstance.getVelocimacro(String, String)

addVelocimacro

public static boolean addVelocimacro(String name,
                                     Node macro,
                                     List<Macro.MacroArg> macroArgs,
                                     String sourceTemplate)
Adds a new Velocimacro. Usually called by Macro only while parsing.

Parameters:
name - Name of a new velocimacro.
macro - root AST node of the parsed macro
macroArgs - Array of macro arguments, containing the #macro() arguments and default values. the 0th is the name.
sourceTemplate - The template from which the macro is requested.
Returns:
boolean True if added, false if rejected for some reason (either parameters or permission settings)
Since:
1.6
See Also:
RuntimeInstance.addVelocimacro(String, Node, List, String)

isVelocimacro

public static boolean isVelocimacro(String vmName,
                                    String templateName)
Checks to see if a VM exists

Parameters:
vmName - Name of the Velocimacro.
templateName - Template on which to look for the Macro.
Returns:
True if VM by that name exists, false if not
See Also:
RuntimeInstance.isVelocimacro(String, String)

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

Parameters:
namespace - Namespace to dump.
Returns:
True if namespace was dumped successfully.
See Also:
RuntimeInstance.dumpVMNamespace(String)

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
See Also:
RuntimeInstance.getString(String)

getInt

public static int getInt(String key)
Int property accessor method to hide the configuration implementation.

Parameters:
key - Property key
Returns:
value
See Also:
RuntimeInstance.getInt(String)

getInt

public static int getInt(String key,
                         int defaultValue)
Int property accessor method to hide the configuration implementation.

Parameters:
key - property key
defaultValue - The default value.
Returns:
value
See Also:
RuntimeInstance.getInt(String, int)

getBoolean

public static boolean getBoolean(String key,
                                 boolean def)
Boolean property accessor method to hide the configuration implementation.

Parameters:
key - property key
def - The default value if property not found.
Returns:
value of key or default value
See Also:
RuntimeInstance.getBoolean(String, boolean)

getConfiguration

public static ExtendedProperties getConfiguration()
Return the velocity runtime configuration object.

Returns:
ExtendedProperties configuration object which houses the velocity runtime properties.
See Also:
RuntimeInstance.getConfiguration()

getIntrospector

public static Introspector getIntrospector()
Return the Introspector for this RuntimeInstance

Returns:
Introspector object for this runtime instance
See Also:
RuntimeInstance.getIntrospector()

getEventCartridge

public EventCartridge getEventCartridge()
Returns the event handlers for the application.

Returns:
The event handlers for the application.
Since:
1.5
See Also:
RuntimeInstance.getApplicationEventCartridge()

getApplicationAttribute

public static Object getApplicationAttribute(Object key)
Gets the application attribute for the given key

Parameters:
key -
Returns:
The application attribute for the given key.
See Also:
RuntimeServices.getApplicationAttribute(Object), RuntimeInstance.getApplicationAttribute(Object)

getUberspect

public static Uberspect getUberspect()
Returns the Uberspect object for this Instance.

Returns:
The Uberspect object for this Instance.
See Also:
RuntimeServices.getUberspect(), RuntimeInstance.getUberspect()

removeDirective

public static void removeDirective(String name)
Remove a directive.

Parameters:
name - name of the directive.

loadDirective

public static void loadDirective(String directiveClass)
Instantiates and loads the directive with some basic checks.

Parameters:
directiveClass - classname of directive to load


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