org.apache.velocity.runtime
Class Runtime

java.lang.Object
  |
  +--org.apache.velocity.runtime.Runtime
All Implemented Interfaces:
RuntimeConstants

public class Runtime
extends java.lang.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:

 Runtime.setProperty(Runtime.FILE_RESOURCE_LOADER_PATH, templatePath);
 Runtime.setProperty(Runtime.RUNTIME_LOG, pathToVelocityLog);
 Runtime.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
 -----------------------------------------------------------------------
 Runtime.init()
 
 If Runtime.init() is called by itself the Runtime will
 initialize with a set of default values.
 -----------------------------------------------------------------------
 Runtime.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: Runtime.java,v 1.110 2001/05/11 04:00:58 geirm Exp $
Author:
Jason van Zyl, Jeff Bowden, Geir Magusson Jr.

Field Summary
private static org.apache.commons.collections.ExtendedProperties configuration
          Object that houses the configuration options for the velocity runtime.
private static java.util.Hashtable globalCache
          The caching system used by the Velocity Runtime
private static boolean initialized
          Indicate whether the Runtime has been fully initialized.
private static LogSystem logSystem
          The Runtime logger.
private static org.apache.commons.collections.ExtendedProperties overridingProperties
          These are the properties that are laid down over top of the default properties when requested.
private static SimplePool parserPool
          The Runtime parser pool
private static java.util.Vector pendingMessages
          The logging systems initialization may be defered if it is to be initialized by an external system.
private static java.util.Hashtable runtimeDirectives
          This is a hashtable of initialized directives.
private static 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_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, UNKNOWN_PREFIX, VM_CONTEXT_LOCALSCOPE, VM_LIBRARY, VM_MESSAGES_ON, VM_PERM_ALLOW_INLINE, VM_PERM_ALLOW_INLINE_REPLACE_GLOBAL, VM_PERM_INLINE_LOCAL, WARN_PREFIX
 
Constructor Summary
Runtime()
           
 
Method Summary
static void addProperty(java.lang.String key, java.lang.Object value)
          Add a property to the configuration.
static boolean addVelocimacro(java.lang.String name, java.lang.String macro, java.lang.String[] argArray, java.lang.String sourceTemplate)
          Adds a new Velocimacro.
static void clearProperty(java.lang.String key)
          Clear the values pertaining to a particular property.
static Parser createNewParser()
          Returns a JavaCC generated Parser.
static void debug(java.lang.Object message)
          Log a debug message.
private static void dumpPendingMessages()
           
static boolean dumpVMNamespace(java.lang.String namespace)
          tells the vmFactory to dump the specified namespace.
static void error(java.lang.Object message)
          Log an error message.
static boolean getBoolean(java.lang.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(java.lang.String name)
          Returns a static content resource from the resource manager.
static ContentResource getContent(java.lang.String name, java.lang.String encoding)
          Returns a static content resource from the resource manager.
static int getInt(java.lang.String key)
          Int property accessor method to hide the configuration implementation.
static int getInt(java.lang.String key, int defaultValue)
          Int property accessor method to hide the configuration implementation.
static java.lang.String getLoaderNameForResource(java.lang.String resourceName)
          Determines is a template exists, and returns name of the loader that provides it.
static java.lang.Object getProperty(java.lang.String key)
          Allows an external caller to get a property.
static java.lang.String getString(java.lang.String key)
          String property accessor method to hide the configuration implementation
static java.lang.String getString(java.lang.String key, java.lang.String defaultValue)
          String property accessor method with default to hide the configuration implementation.
static Template getTemplate(java.lang.String name)
          Returns a Template from the resource manager.
static Template getTemplate(java.lang.String name, java.lang.String encoding)
          Returns a Template from the resource manager
static Directive getVelocimacro(java.lang.String vmName, java.lang.String templateName)
          Returns the appropriate VelocimacroProxy object if strVMname is a valid current Velocimacro.
static void info(java.lang.Object message)
          Log an info message.
static void init()
           
static void init(java.util.Properties p)
          Initialize the Velocity Runtime with a Properties object.
static void init(java.lang.String configurationFile)
          Initialize the Velocity Runtime with the name of ExtendedProperties object.
private static void initializeDirectives()
          This methods initializes all the directives that are used by the Velocity Runtime.
private static void initializeGlobalCache()
          Initialize the global cache use by the Velocity runtime.
private static void initializeLogger()
          Initialize the Velocity logging system.
private static void initializeParserPool()
          Initializes the Velocity parser pool.
private static void initializeProperties()
          Initialize Velocity properties, if the default properties have not been laid down first then do so.
static boolean isVelocimacro(java.lang.String vmName, java.lang.String templateName)
          Checks to see if a VM exists
private static void log(int level, java.lang.Object message)
          Handle logging.
static SimpleNode parse(java.io.Reader reader, java.lang.String templateName)
          Parse the input stream and return the root of AST node structure.
static void setConfiguration(org.apache.commons.collections.ExtendedProperties configuration)
          Allow an external system to set an ExtendedProperties object to use.
private static void setDefaultProperties()
          Initializes the Velocity Runtime with properties file.
static void setProperty(java.lang.String key, java.lang.Object value)
          Allows an external system to set a property in the Velocity Runtime.
private static boolean showStackTrace()
          Added this to check and make sure that the configuration is initialized before trying to get properties from it.
static void warn(java.lang.Object message)
          Log a warning message.
 
Methods inherited from class java.lang.Object
, clone, equals, finalize, getClass, hashCode, notify, notifyAll, registerNatives, toString, wait, wait, wait
 

Field Detail

vmFactory

private static VelocimacroFactory vmFactory
VelocimacroFactory object to manage VMs

logSystem

private static LogSystem logSystem
The Runtime logger.

globalCache

private static java.util.Hashtable globalCache
The caching system used by the Velocity Runtime

parserPool

private static SimplePool parserPool
The Runtime parser pool

initialized

private static boolean initialized
Indicate whether the Runtime has been fully initialized.

overridingProperties

private static org.apache.commons.collections.ExtendedProperties overridingProperties
These are the properties that are laid down over top of the default properties when requested.

pendingMessages

private static java.util.Vector pendingMessages
The logging systems initialization may be defered if it is to be initialized by an external system. There may be messages that need to be stored until the logger is instantiated. They will be stored here until the logger is alive.

runtimeDirectives

private static 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 static 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.
Constructor Detail

Runtime

public Runtime()
Method Detail

init

public static void init()
                 throws java.lang.Exception

setDefaultProperties

private static 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 static void setProperty(java.lang.String key,
                               java.lang.Object value)
Allows an external system to set a property in the Velocity Runtime.
Parameters:
String - property key
String - 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:
ExtendedProperties - configuration

addProperty

public static 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"]
Parameters:
String - key
String - value

clearProperty

public static void clearProperty(java.lang.String key)
Clear the values pertaining to a particular property.
Parameters:
String - key of property to clear

getProperty

public static 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.
Parameters:
key - property to return

initializeProperties

private static 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 static void init(java.util.Properties p)
                 throws java.lang.Exception
Initialize the Velocity Runtime with a Properties object.
Parameters:
Properties -  

init

public static void init(java.lang.String configurationFile)
                 throws java.lang.Exception
Initialize the Velocity Runtime with the name of ExtendedProperties object.
Parameters:
Properties -  

initializeLogger

private static void initializeLogger()
                              throws java.lang.Exception
Initialize the Velocity logging system.
Throws:
java.lang.Exception -  

dumpPendingMessages

private static void dumpPendingMessages()

initializeDirectives

private static 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 -  

initializeParserPool

private static void initializeParserPool()
Initializes the Velocity parser pool. This still needs to be implemented.

createNewParser

public static Parser createNewParser()
Returns a JavaCC generated Parser.
Returns:
Parser javacc generated parser

parse

public static SimpleNode parse(java.io.Reader reader,
                               java.lang.String templateName)
                        throws ParseException
Parse the input stream 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:
InputStream - inputstream retrieved by a resource loader
String - name of the template being parsed

initializeGlobalCache

private static void initializeGlobalCache()
Initialize the global cache use by the Velocity runtime. Cached templates will be stored here, as well as cached content pulled in by the #include directive. Who knows what else we'll find to cache.

getTemplate

public static 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"
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 static Template getTemplate(java.lang.String name,
                                   java.lang.String encoding)
                            throws ResourceNotFoundException,
                                   ParseErrorException,
                                   java.lang.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.
java.lang.Exception - if an error occurs in template initialization

getContent

public static 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.
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.

getContent

public static 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.
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.

getLoaderNameForResource

public static 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.
Parameters:
resourceName - Name of template or content resource
Returns:
class name of loader than can provide it

showStackTrace

private static 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 static void log(int level,
                        java.lang.Object message)
Handle logging.
Parameters:
String - message to log

warn

public static void warn(java.lang.Object message)
Log a warning message.
Parameters:
Object - message to log

info

public static void info(java.lang.Object message)
Log an info message.
Parameters:
Object - message to log

error

public static void error(java.lang.Object message)
Log an error message.
Parameters:
Object - message to log

debug

public static void debug(java.lang.Object message)
Log a debug message.
Parameters:
Object - message to log

getString

public static java.lang.String getString(java.lang.String key,
                                         java.lang.String defaultValue)
String property accessor method with default to hide the configuration implementation.
Parameters:
String - key property key
String - defaultValue default value to return if key not found in resource manager.
Returns:
String value of key or default

getVelocimacro

public static Directive getVelocimacro(java.lang.String vmName,
                                       java.lang.String templateName)
Returns the appropriate VelocimacroProxy object if strVMname is a valid current Velocimacro.
Parameters:
String - vmName Name of velocimacro requested
Returns:
String VelocimacroProxy

addVelocimacro

public static 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.
Parameters:
String - name Name of velocimacro
String - macro String form of macro body
String - argArray Array of strings, containing the #macro() arguments. the 0th is the name.
Returns:
boolean True if added, false if rejected for some reason (either parameters or permission settings)

isVelocimacro

public static boolean isVelocimacro(java.lang.String vmName,
                                    java.lang.String templateName)
Checks to see if a VM exists
Parameters:
name - Name of velocimacro
Returns:
boolean True if VM by that name exists, false if not

dumpVMNamespace

public static 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

getString

public static java.lang.String getString(java.lang.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(java.lang.String key)
Int property accessor method to hide the configuration implementation.
Parameters:
String - key property key
Returns:
int value

getInt

public static int getInt(java.lang.String key,
                         int defaultValue)
Int property accessor method to hide the configuration implementation.
Parameters:
key - property key
int - default value
Returns:
int value

getBoolean

public static boolean getBoolean(java.lang.String key,
                                 boolean def)
Boolean property accessor method to hide the configuration implementation.
Parameters:
String - key property key
boolean - default default value if property not found
Returns:
boolean value of key or default value

getConfiguration

public static org.apache.commons.collections.ExtendedProperties getConfiguration()
Return the velocity runtime configuration object.
Returns:
ExtendedProperties configuration object which houses the velocity runtime properties.


Copyright © 2001 Apache Software Foundation. All Rights Reserved.