org.apache.velocity.runtime
Class RuntimeInstance

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

All Implemented Interfaces:

RuntimeConstants, RuntimeLogger, RuntimeServices

public class RuntimeInstance

extends java.lang.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,v 1.19.4.1 2004/03/03 23:22:55 geirm Exp $

Author:

Jason van Zyl, Jeff Bowden, Geir Magusson Jr.

Field Summary

private java.util.Map	applicationAttributes
private org.apache.commons.collections.ExtendedProperties	configuration Object that houses the configuration options for the velocity runtime.
private boolean	initialized Indicate whether the Runtime has been fully initialized.
private Introspector	introspector
private LogSystem	logSystem The Runtime logger.
private org.apache.commons.collections.ExtendedProperties	overridingProperties These are the properties that are laid down over top of the default properties when requested.
private SimplePool	parserPool The Runtime parser pool
private ResourceManager	resourceManager
private java.util.Hashtable	runtimeDirectives This is a hashtable of initialized directives.
private Uberspect	uberSpect
private VelocimacroFactory	vmFactory VelocimacroFactory object to manage VMs

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

COUNTER_INITIAL_VALUE, COUNTER_NAME, DEBUG_PREFIX, DEFAULT_RUNTIME_DIRECTIVES, DEFAULT_RUNTIME_PROPERTIES, ENCODING_DEFAULT, ERROR_PREFIX, ERRORMSG_END, ERRORMSG_START, FILE_RESOURCE_LOADER_CACHE, FILE_RESOURCE_LOADER_PATH, INFO_PREFIX, INPUT_ENCODING, INTERPOLATE_STRINGLITERALS, LOGSYSTEM_LOG4J_EMAIL_BUFFER_SIZE, LOGSYSTEM_LOG4J_EMAIL_FROM, LOGSYSTEM_LOG4J_EMAIL_SERVER, LOGSYSTEM_LOG4J_EMAIL_SUBJECT, LOGSYSTEM_LOG4J_EMAIL_TO, LOGSYSTEM_LOG4J_FILE_BACKUPS, LOGSYSTEM_LOG4J_FILE_SIZE, LOGSYSTEM_LOG4J_PATTERN, LOGSYSTEM_LOG4J_REMOTE_HOST, LOGSYSTEM_LOG4J_REMOTE_PORT, LOGSYSTEM_LOG4J_SYSLOGD_FACILITY, LOGSYSTEM_LOG4J_SYSLOGD_HOST, NUMBER_OF_PARSERS, OUTPUT_ENCODING, PARSE_DIRECTIVE_MAXDEPTH, PARSER_POOL_SIZE, RESOURCE_LOADER, RESOURCE_MANAGER_CACHE_CLASS, RESOURCE_MANAGER_CLASS, RESOURCE_MANAGER_LOGWHENFOUND, RUNTIME_LOG, RUNTIME_LOG_ERROR_STACKTRACE, RUNTIME_LOG_INFO_STACKTRACE, RUNTIME_LOG_LOGSYSTEM, RUNTIME_LOG_LOGSYSTEM_CLASS, RUNTIME_LOG_REFERENCE_LOG_INVALID, RUNTIME_LOG_WARN_STACKTRACE, UBERSPECT_CLASSNAME, UNKNOWN_PREFIX, VM_CONTEXT_LOCALSCOPE, VM_LIBRARY, VM_LIBRARY_AUTORELOAD, VM_MESSAGES_ON, VM_PERM_ALLOW_INLINE, VM_PERM_ALLOW_INLINE_REPLACE_GLOBAL, VM_PERM_INLINE_LOCAL, WARN_PREFIX

Constructor Summary

RuntimeInstance()

Method Summary

void	addProperty(java.lang.String key, java.lang.Object value) Add a property to the configuration.
boolean	addVelocimacro(java.lang.String name, java.lang.String macro, java.lang.String[] argArray, java.lang.String sourceTemplate) Adds a new Velocimacro.
void	clearProperty(java.lang.String key) Clear the values pertaining to a particular property.
Parser	createNewParser() Returns a JavaCC generated Parser.
void	debug(java.lang.Object message) Log a debug message.
boolean	dumpVMNamespace(java.lang.String namespace) tells the vmFactory to dump the specified namespace.
void	error(java.lang.Object message) Log an error message.
java.lang.Object	getApplicationAttribute(java.lang.Object key) Return the specified applcation attribute.
boolean	getBoolean(java.lang.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(java.lang.String name) Returns a static content resource from the resource manager.
ContentResource	getContent(java.lang.String name, java.lang.String encoding) Returns a static content resource from the resource manager.
int	getInt(java.lang.String key) Int property accessor method to hide the configuration implementation.
int	getInt(java.lang.String key, int defaultValue) Int property accessor method to hide the configuration implementation.
Introspector	getIntrospector() Return the Introspector for this instance
java.lang.String	getLoaderNameForResource(java.lang.String resourceName) Determines is a template exists, and returns name of the loader that provides it.
java.lang.Object	getProperty(java.lang.String key) Allows an external caller to get a property.
java.lang.String	getString(java.lang.String key) String property accessor method to hide the configuration implementation
java.lang.String	getString(java.lang.String key, java.lang.String defaultValue) String property accessor method with default to hide the configuration implementation.
Template	getTemplate(java.lang.String name) Returns a Template from the resource manager.
Template	getTemplate(java.lang.String name, java.lang.String encoding) Returns a Template from the resource manager
Uberspect	getUberspect() Returns the configured class introspection/reflection implemenation.
Directive	getVelocimacro(java.lang.String vmName, java.lang.String templateName) Returns the appropriate VelocimacroProxy object if strVMname is a valid current Velocimacro.
void	info(java.lang.Object message) Log an info message.
void	init()
void	init(java.util.Properties p) Initialize the Velocity Runtime with a Properties object.
void	init(java.lang.String configurationFile) Initialize the Velocity Runtime with the name of ExtendedProperties object.
private void	initializeDirectives() This methods initializes all the directives that are used by the Velocity Runtime.
private void	initializeIntrospection() Gets the classname for the Uberspect introspection package and instantiates an instance.
private void	initializeLogger() Initialize the Velocity logging system.
private void	initializeParserPool() Initializes the Velocity parser pool.
private void	initializeProperties() Initialize Velocity properties, if the default properties have not been laid down first then do so.
private void	initializeResourceManager()
boolean	isVelocimacro(java.lang.String vmName, java.lang.String templateName) Checks to see if a VM exists
private void	loadDirective(java.lang.String directiveClass, java.lang.String caption) instantiates and loads the directive with some basic checks
private void	log(int level, java.lang.Object message) Handle logging.
SimpleNode	parse(java.io.Reader reader, java.lang.String templateName) Parse the input and return the root of AST node structure.
SimpleNode	parse(java.io.Reader reader, java.lang.String templateName, boolean dumpNamespace) Parse the input and return the root of the AST node structure.
java.lang.Object	setApplicationAttribute(java.lang.Object key, java.lang.Object o)
void	setConfiguration(org.apache.commons.collections.ExtendedProperties configuration) Allow an external system to set an ExtendedProperties object to use.
private void	setDefaultProperties() Initializes the Velocity Runtime with properties file.
void	setProperty(java.lang.String key, java.lang.Object value) Allows an external system to set a property in the Velocity Runtime.
private boolean	showStackTrace() Added this to check and make sure that the configuration is initialized before trying to get properties from it.
void	warn(java.lang.Object message) Log a warning message.

Methods inherited from class java.lang.Object

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

Field Detail

vmFactory

private VelocimacroFactory vmFactory

VelocimacroFactory object to manage VMs

logSystem

private LogSystem logSystem

The Runtime logger. We start with an instance of a 'primordial logger', which just collects log messages then, when the log system is initialized, we dump all messages out of the primordial one into the real one.

parserPool

private SimplePool parserPool

The Runtime parser pool

initialized

private boolean initialized

Indicate whether the Runtime has been fully initialized.

overridingProperties

private org.apache.commons.collections.ExtendedProperties overridingProperties

These are the properties that are laid down over top of the default properties when requested.

runtimeDirectives

private java.util.Hashtable runtimeDirectives

This is a hashtable of initialized directives. The directives that populate this hashtable are taken from the RUNTIME_DEFAULT_DIRECTIVES property file. This hashtable is passed to each parser that is created.

configuration

private org.apache.commons.collections.ExtendedProperties configuration

Object that houses the configuration options for the velocity runtime. The ExtendedProperties object allows the convenient retrieval of a subset of properties. For example all the properties for a resource loader can be retrieved from the main ExtendedProperties object using something like the following: ExtendedProperties loaderConfiguration = configuration.subset(loaderID); And a configuration is a lot more convenient to deal with then conventional properties objects, or Maps.

resourceManager

private ResourceManager resourceManager

introspector

private Introspector introspector

applicationAttributes

private java.util.Map applicationAttributes

uberSpect

private Uberspect uberSpect

Constructor Detail

RuntimeInstance

public RuntimeInstance()

Method Detail

init

public void init()
          throws java.lang.Exception

Specified by:

init in interface RuntimeServices

Throws:

java.lang.Exception

initializeIntrospection

private void initializeIntrospection()
                              throws java.lang.Exception

Gets the classname for the Uberspect introspection package and instantiates an instance.

Throws:

java.lang.Exception

setDefaultProperties

private void setDefaultProperties()

Initializes the Velocity Runtime with properties file. The properties file may be in the file system proper, or the properties file may be in the classpath.

setProperty

public void setProperty(java.lang.String key,
                        java.lang.Object value)

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

Specified by:

setProperty in interface RuntimeServices

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

addProperty

public void addProperty(java.lang.String key,
                        java.lang.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

clearProperty

public void clearProperty(java.lang.String key)

Clear the values pertaining to a particular property.

Specified by:

clearProperty in interface RuntimeServices

getProperty

public java.lang.Object getProperty(java.lang.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

initializeProperties

private void initializeProperties()

Initialize Velocity properties, if the default properties have not been laid down first then do so. Then proceed to process any overriding properties. Laying down the default properties gives a much greater chance of having a working system.

init

public void init(java.util.Properties p)
          throws java.lang.Exception

Initialize the Velocity Runtime with a Properties object.

Specified by:

init in interface RuntimeServices

Throws:

java.lang.Exception

init

public void init(java.lang.String configurationFile)
          throws java.lang.Exception

Initialize the Velocity Runtime with the name of ExtendedProperties object.

Specified by:

init in interface RuntimeServices

Throws:

java.lang.Exception

initializeResourceManager

private void initializeResourceManager()
                                throws java.lang.Exception

Throws:

java.lang.Exception

initializeLogger

private void initializeLogger()
                       throws java.lang.Exception

Initialize the Velocity logging system.

Throws:

java.lang.Exception

initializeDirectives

private void initializeDirectives()
                           throws java.lang.Exception

This methods initializes all the directives that are used by the Velocity Runtime. The directives to be initialized are listed in the RUNTIME_DEFAULT_DIRECTIVES properties file.

Throws:

java.lang.Exception

loadDirective

private void loadDirective(java.lang.String directiveClass,
                           java.lang.String caption)

instantiates and loads the directive with some basic checks

Parameters:

directiveClass - classname of directive to load

initializeParserPool

private void initializeParserPool()

Initializes the Velocity parser pool. This still needs to be implemented.

createNewParser

public Parser createNewParser()

Returns a JavaCC generated Parser.

Returns:

Parser javacc generated parser

parse

public SimpleNode parse(java.io.Reader reader,
                        java.lang.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

Throws:

ParseException

parse

public SimpleNode parse(java.io.Reader reader,
                        java.lang.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:

dumpNamespace - flag to dump the Velocimacro namespace for this template

Throws:

ParseException

getTemplate

public Template getTemplate(java.lang.String name)
                     throws ResourceNotFoundException,
                            ParseErrorException,
                            java.lang.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.

java.lang.Exception - if an error occurs in template initialization

getTemplate

public Template getTemplate(java.lang.String name,
                            java.lang.String encoding)
                     throws ResourceNotFoundException,
                            ParseErrorException,
                            java.lang.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.

java.lang.Exception - if an error occurs in template initialization

getContent

public ContentResource getContent(java.lang.String name)
                           throws ResourceNotFoundException,
                                  ParseErrorException,
                                  java.lang.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

java.lang.Exception

getContent

public ContentResource getContent(java.lang.String name,
                                  java.lang.String encoding)
                           throws ResourceNotFoundException,
                                  ParseErrorException,
                                  java.lang.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

java.lang.Exception

getLoaderNameForResource

public java.lang.String getLoaderNameForResource(java.lang.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

showStackTrace

private boolean showStackTrace()

Added this to check and make sure that the configuration is initialized before trying to get properties from it. This occurs when there are errors during initialization and the default properties have yet to be layed down.

log

private void log(int level,
                 java.lang.Object message)

Handle logging.

warn

public void warn(java.lang.Object message)

Log a warning message.

Specified by:

warn in interface RuntimeLogger

info

public void info(java.lang.Object message)

Log an info message.

Specified by:

info in interface RuntimeLogger

error

public void error(java.lang.Object message)

Log an error message.

Specified by:

error in interface RuntimeLogger

debug

public void debug(java.lang.Object message)

Log a debug message.

Specified by:

debug in interface RuntimeLogger

getString

public java.lang.String getString(java.lang.String key,
                                  java.lang.String defaultValue)

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

Specified by:

getString in interface RuntimeServices

Returns:

String value of key or default

getVelocimacro

public Directive getVelocimacro(java.lang.String vmName,
                                java.lang.String templateName)

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

Specified by:

getVelocimacro in interface RuntimeServices

Returns:

String VelocimacroProxy

addVelocimacro

public boolean addVelocimacro(java.lang.String name,
                              java.lang.String macro,
                              java.lang.String[] argArray,
                              java.lang.String sourceTemplate)

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

Specified by:

addVelocimacro in interface RuntimeServices

Returns:

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

isVelocimacro

public boolean isVelocimacro(java.lang.String vmName,
                             java.lang.String templateName)

Checks to see if a VM exists

Specified by:

isVelocimacro in interface RuntimeServices

Returns:

boolean True if VM by that name exists, false if not

dumpVMNamespace

public boolean dumpVMNamespace(java.lang.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 java.lang.String getString(java.lang.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(java.lang.String key)

Int property accessor method to hide the configuration implementation.

Specified by:

getInt in interface RuntimeServices

Returns:

int value

getInt

public int getInt(java.lang.String key,
                  int defaultValue)

Int property accessor method to hide the configuration implementation.

Specified by:

getInt in interface RuntimeServices

Parameters:

key - property key

Returns:

int value

getBoolean

public boolean getBoolean(java.lang.String key,
                          boolean def)

Boolean property accessor method to hide the configuration implementation.

Specified by:

getBoolean in interface RuntimeServices

Returns:

boolean 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:

ExtendedProperties 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 java.lang.Object getApplicationAttribute(java.lang.Object key)

Description copied from interface: RuntimeServices

Return the specified applcation attribute.

Specified by:

getApplicationAttribute in interface RuntimeServices

Parameters:

key - The name of the attribute to retrieve.

setApplicationAttribute

public java.lang.Object setApplicationAttribute(java.lang.Object key,
                                                java.lang.Object o)

getUberspect

public Uberspect getUberspect()

Description copied from interface: RuntimeServices

Returns the configured class introspection/reflection implemenation.

Specified by:

getUberspect in interface RuntimeServices