org.apache.velocity.runtime
Class RuntimeInstance

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

All Implemented Interfaces:

RuntimeConstants, RuntimeServices

public class RuntimeInstance
extends Object
implements RuntimeConstants, RuntimeServices

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:

 ri.setProperty(Runtime.FILE_RESOURCE_LOADER_PATH, templatePath);
 ri.setProperty(Runtime.RUNTIME_LOG, pathToVelocityLog);
 ri.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
 -----------------------------------------------------------------------
 init()
 
 If init() is called by itself the RuntimeInstance will initialize
 with a set of default values.
 -----------------------------------------------------------------------
 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: RuntimeInstance.java 151549 2005-02-06 06:19:43Z wglass $

Author:

Jason van Zyl, Jeff Bowden, Geir Magusson Jr.

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

RuntimeInstance()

Method Summary

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

RuntimeInstance

public RuntimeInstance()

Method Detail

init

public void init()
          throws Exception

Specified by:

init in interface RuntimeServices

Throws:

Exception

setProperty

public void setProperty(String key,
                        Object value)

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

Specified by:

setProperty in interface RuntimeServices

Parameters:

key - property key

value - property value

setConfiguration

public 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.

Specified by:

setConfiguration in interface RuntimeServices

Parameters:

configuration -

addProperty

public 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"]

Specified by:

addProperty in interface RuntimeServices

Parameters:

key -

value -

clearProperty

public void clearProperty(String key)

Clear the values pertaining to a particular property.

Specified by:

clearProperty in interface RuntimeServices

Parameters:

key - of property to clear

getProperty

public 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.

Specified by:

getProperty in interface RuntimeServices

Parameters:

key - property to return

init

public void init(Properties p)
          throws Exception

Initialize the Velocity Runtime with a Properties object.

Specified by:

init in interface RuntimeServices

Parameters:

p -

Throws:

Exception

init

public void init(String configurationFile)
          throws Exception

Initialize the Velocity Runtime with the name of ExtendedProperties object.

Specified by:

init in interface RuntimeServices

Parameters:

configurationFile -

Throws:

Exception

createNewParser

public Parser createNewParser()

Returns a JavaCC generated Parser.

Returns:

Parser javacc generated parser

parse

public 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.

Specified by:

parse in interface RuntimeServices

Parameters:

reader - Reader retrieved by a resource loader

templateName - name of the template being parsed

Throws:

ParseException

parse

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

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

Specified by:

parse in interface RuntimeServices

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

Throws:

ParseException

getTemplate

public 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"

Specified by:

getTemplate in interface RuntimeServices

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

Returns a Template from the resource manager

Specified by:

getTemplate in interface RuntimeServices

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 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.

Specified by:

getContent in interface RuntimeServices

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

Returns a static content resource from the resource manager.

Specified by:

getContent in interface RuntimeServices

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 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.

Specified by:

getLoaderNameForResource in interface RuntimeServices

Parameters:

resourceName - Name of template or content resource

Returns:

class name of loader than can provide it

getString

public String getString(String key,
                        String defaultValue)

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

Specified by:

getString in interface RuntimeServices

Parameters:

key - property key

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

Returns:

value of key or default

getVelocimacro

public Directive getVelocimacro(String vmName,
                                String templateName)

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

Specified by:

getVelocimacro in interface RuntimeServices

Parameters:

vmName - Name of velocimacro requested

templateName -

Returns:

The requested VelocimacroProxy.

addVelocimacro

public 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.

Specified by:

addVelocimacro in interface RuntimeServices

Parameters:

name - Name of velocimacro

macro - String form of macro body

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

sourceTemplate -

line - the line, where the macro starts

column - the column, where the macro starts

Returns:

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

isVelocimacro

public boolean isVelocimacro(String vmName,
                             String templateName)

Checks to see if a VM exists

Specified by:

isVelocimacro in interface RuntimeServices

Parameters:

vmName - Name of the Velocimacro.

templateName -

Returns:

True if VM by that name exists, false if not

dumpVMNamespace

public 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

Specified by:

dumpVMNamespace in interface RuntimeServices

getString

public String getString(String key)

String property accessor method to hide the configuration implementation

Specified by:

getString in interface RuntimeServices

Parameters:

key - property key

Returns:

value of key or null

getInt

public int getInt(String key)

Int property accessor method to hide the configuration implementation.

Specified by:

getInt in interface RuntimeServices

Parameters:

key - Property key

Returns:

value

getInt

public int getInt(String key,
                  int defaultValue)

Int property accessor method to hide the configuration implementation.

Specified by:

getInt in interface RuntimeServices

Parameters:

key - property key

defaultValue - default value

Returns:

value

getBoolean

public boolean getBoolean(String key,
                          boolean def)

Boolean property accessor method to hide the configuration implementation.

Specified by:

getBoolean in interface RuntimeServices

Parameters:

key - property key

def - default value if property not found

Returns:

value of key or default value

getConfiguration

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

Return the velocity runtime configuration object.

Specified by:

getConfiguration in interface RuntimeServices

Returns:

Configuration object which houses the Velocity runtime properties.

getIntrospector

public Introspector getIntrospector()

Return the Introspector for this instance

Specified by:

getIntrospector in interface RuntimeServices

getApplicationAttribute

public Object getApplicationAttribute(Object key)

Gets the application attribute for the given key

Specified by:

getApplicationAttribute in interface RuntimeServices

Parameters:

key -

Returns:

the requested attribute or null if not available

setApplicationAttribute

public Object setApplicationAttribute(Object key,
                                      Object o)

Sets the application attribute for the given key

Parameters:

key -

o -

Returns:

the replaced object, if there was already an attribute with the same key

getUberspect

public Uberspect getUberspect()

Description copied from interface: RuntimeServices

Returns the configured class introspection/reflection implemenation.

Specified by:

getUberspect in interface RuntimeServices