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Apache Velocity is a general purpose template engine.
package org.apache.velocity.runtime;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
import java.io.Reader;
import java.util.Properties;
import org.apache.commons.collections.ExtendedProperties;
import org.apache.velocity.Template;
import org.apache.velocity.app.event.EventCartridge;
import org.apache.velocity.exception.ParseErrorException;
import org.apache.velocity.exception.ResourceNotFoundException;
import org.apache.velocity.runtime.directive.Directive;
import org.apache.velocity.runtime.log.Log;
import org.apache.velocity.runtime.parser.ParseException;
import org.apache.velocity.runtime.parser.node.Node;
import org.apache.velocity.runtime.parser.node.SimpleNode;
import org.apache.velocity.runtime.resource.ContentResource;
import org.apache.velocity.util.introspection.Introspector;
import org.apache.velocity.util.introspection.Uberspect;
/**
* 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.
* -----------------------------------------------------------------------
*
*
* @author Jason van Zyl
* @author Jeff Bowden
* @author Geir Magusson Jr.
* @author Daniel Rall
*
* @see org.apache.velocity.runtime.RuntimeInstance
*
* @version $Id: RuntimeSingleton.java 685724 2008-08-13 23:12:12Z nbubna $
*/
public class RuntimeSingleton implements RuntimeConstants
{
private static RuntimeInstance ri = new RuntimeInstance();
/**
* This is the primary initialization method in the Velocity
* Runtime. The systems that are setup/initialized here are
* as follows:
*
*
* - Logging System
* - ResourceManager
* - Event Handlers
* - Parser Pool
* - Global Cache
* - Static Content Include System
* - Velocimacro System
*
* @throws Exception When an error occured during initialization.
* @see RuntimeInstance#init()
*/
public synchronized static void init()
throws Exception
{
ri.init();
}
/**
* Returns true if the RuntimeInstance has been successfully initialized.
* @return True if the RuntimeInstance has been successfully initialized.
* @see RuntimeInstance#isInitialized()
* @since 1.5
*/
public static boolean isInitialized()
{
return ri.isInitialized();
}
/**
* Returns the RuntimeServices Instance used by this wrapper.
*
* @return The RuntimeServices Instance used by this wrapper.
*/
public static RuntimeServices getRuntimeServices()
{
return ri;
}
/**
* Allows an external system to set a property in
* the Velocity Runtime.
*
* @param key property key
* @param value property value
* @see RuntimeInstance#setProperty(String, Object)
*/
public static void setProperty(String key, Object value)
{
ri.setProperty( key, value );
}
/**
* 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.
*
* @param configuration
* @see RuntimeInstance#setConfiguration(ExtendedProperties)
*/
public static void setConfiguration( ExtendedProperties configuration)
{
ri.setConfiguration( configuration );
}
/**
* 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"]
*
* @param key
* @param value
* @see RuntimeInstance#addProperty(String, Object)
*/
public static void addProperty(String key, Object value)
{
ri.addProperty( key, value );
}
/**
* Clear the values pertaining to a particular
* property.
*
* @param key of property to clear
* @see RuntimeInstance#clearProperty(String)
*/
public static void clearProperty(String key)
{
ri.clearProperty( 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.
*
* @param key property to return
* @return Value of the property or null if it does not exist.
* @see RuntimeInstance#getProperty(String)
*/
public static Object getProperty( String key )
{
return ri.getProperty( key );
}
/**
* Initialize the Velocity Runtime with a Properties
* object.
*
* @param p
* @throws Exception When an error occurs during initialization.
* @see RuntimeInstance#init(Properties)
*/
public static void init(Properties p) throws Exception
{
ri.init(p);
}
/**
* Initialize the Velocity Runtime with the name of
* ExtendedProperties object.
*
* @param configurationFile
* @throws Exception When an error occurs during initialization.
* @see RuntimeInstance#init(String)
*/
public static void init(String configurationFile)
throws Exception
{
ri.init( configurationFile );
}
/**
* 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.
*
* @param reader Reader retrieved by a resource loader
* @param templateName name of the template being parsed
* @return A root node representing the template as an AST tree.
* @throws ParseException When the template could not be parsed.
* @see RuntimeInstance#parse(Reader, String)
*/
public static SimpleNode parse( Reader reader, String templateName )
throws ParseException
{
return ri.parse( reader, templateName );
}
/**
* Parse the input and return the root of the AST node structure.
*
* @param reader Reader retrieved by a resource loader
* @param templateName name of the template being parsed
* @param dumpNamespace flag to dump the Velocimacro namespace for this template
* @return A root node representing the template as an AST tree.
* @throws ParseException When the template could not be parsed.
* @see RuntimeInstance#parse(Reader, String, boolean)
*/
public static SimpleNode parse( Reader reader, String templateName, boolean dumpNamespace )
throws ParseException
{
return ri.parse( reader, templateName, dumpNamespace );
}
/**
* 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"
*
* @param name The file name of the desired template.
* @return The template.
* @throws ResourceNotFoundException if template not found
* from any available source.
* @throws ParseErrorException if template cannot be parsed due
* to syntax (or other) error.
* @throws Exception if an error occurs in template initialization
* @see RuntimeInstance#getTemplate(String)
*/
public static Template getTemplate(String name)
throws ResourceNotFoundException, ParseErrorException, Exception
{
return ri.getTemplate( name );
}
/**
* Returns a Template from the resource manager
*
* @param name The name of the desired template.
* @param encoding Character encoding of the template
* @return The template.
* @throws ResourceNotFoundException if template not found
* from any available source.
* @throws ParseErrorException if template cannot be parsed due
* to syntax (or other) error.
* @throws Exception if an error occurs in template initialization
* @throws ParseErrorException When the template could not be parsed.
* @throws Exception Any other error.
* @see RuntimeInstance#getTemplate(String, String)
*/
public static Template getTemplate(String name, String encoding)
throws ResourceNotFoundException, ParseErrorException, Exception
{
return ri.getTemplate( name, encoding );
}
/**
* Returns a static content resource from the
* resource manager. Uses the current value
* if INPUT_ENCODING as the character encoding.
*
* @param name Name of content resource to get
* @return parsed ContentResource object ready for use
* @throws ResourceNotFoundException if template not found
* from any available source.
* @throws ParseErrorException When the template could not be parsed.
* @throws Exception Any other error.
* @see RuntimeInstance#getContent(String)
*/
public static ContentResource getContent(String name)
throws ResourceNotFoundException, ParseErrorException, Exception
{
return ri.getContent( name );
}
/**
* Returns a static content resource from the
* resource manager.
*
* @param name Name of content resource to get
* @param encoding Character encoding to use
* @return parsed ContentResource object ready for use
* @throws ResourceNotFoundException if template not found
* from any available source.
* @throws ParseErrorException When the template could not be parsed.
* @throws Exception Any other error.
* @see RuntimeInstance#getContent(String, String)
*/
public static ContentResource getContent( String name, String encoding )
throws ResourceNotFoundException, ParseErrorException, Exception
{
return ri.getContent( name, encoding );
}
/**
* 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.
*
* @param resourceName Name of template or content resource
* @return class name of loader than can provide it
* @see RuntimeInstance#getLoaderNameForResource(String)
*/
public static String getLoaderNameForResource( String resourceName )
{
return ri.getLoaderNameForResource( resourceName );
}
/**
* Returns a convenient Log instance that wraps the current LogChute.
*
* @return A convenience Log instance that wraps the current LogChute.
* @see RuntimeInstance#getLog()
* @since 1.5
*/
public static Log getLog()
{
return ri.getLog();
}
/**
* @deprecated Use getLog() and call warn() on it.
* @see Log#warn(Object)
* @param message The message to log.
*/
public static void warn(Object message)
{
getLog().warn(message);
}
/**
* @deprecated Use getLog() and call info() on it.
* @see Log#info(Object)
* @param message The message to log.
*/
public static void info(Object message)
{
getLog().info(message);
}
/**
* @deprecated Use getLog() and call error() on it.
* @see Log#error(Object)
* @param message The message to log.
*/
public static void error(Object message)
{
getLog().error(message);
}
/**
* @deprecated Use getLog() and call debug() on it.
* @see Log#debug(Object)
* @param message The message to log.
*/
public static void debug(Object message)
{
getLog().debug(message);
}
/**
* String property accessor method with default to hide the
* configuration implementation.
*
* @param key property key
* @param defaultValue default value to return if key not
* found in resource manager.
* @return value of key or default
* @see RuntimeInstance#getString(String, String)
*/
public static String getString( String key, String defaultValue)
{
return ri.getString( key, defaultValue );
}
/**
* Returns the appropriate VelocimacroProxy object if strVMname
* is a valid current Velocimacro.
*
* @param vmName Name of velocimacro requested
* @param templateName Name of the template that contains the velocimacro.
* @return The requested VelocimacroProxy.
* @see RuntimeInstance#getVelocimacro(String, String)
*/
public static Directive getVelocimacro( String vmName, String templateName )
{
return ri.getVelocimacro( vmName, templateName );
}
/**
* Adds a new Velocimacro. Usually called by Macro only while parsing.
*
* @param name Name of a new velocimacro.
* @param macro root AST node of the parsed macro
* @param argArray Array of strings, containing the
* #macro() arguments. the 0th argument is the name.
* @param sourceTemplate The template from which the macro is requested.
* @return boolean True if added, false if rejected for some
* reason (either parameters or permission settings)
* @see RuntimeInstance#addVelocimacro(String, Node, String[], String)
* @since 1.6
*/
public static boolean addVelocimacro(String name, Node macro,
String argArray[], String sourceTemplate)
{
return ri.addVelocimacro(name, macro, argArray, sourceTemplate);
}
/**
* Adds a new Velocimacro. Usually called by Macro only while parsing.
*
* @param name Name of velocimacro
* @param macro String form of macro body
* @param argArray Array of strings, containing the
* #macro() arguments. the 0th is the name.
* @param sourceTemplate Name of the template that contains the velocimacro.
* @return True if added, false if rejected for some
* reason (either parameters or permission settings)
*
* @deprecated Use addVelocimacro(String, Node, String[], String) instead
*
* @see RuntimeInstance#addVelocimacro(String, String, String[], String)
*/
public static boolean addVelocimacro( String name,
String macro,
String argArray[],
String sourceTemplate )
{
return ri.addVelocimacro( name, macro, argArray, sourceTemplate );
}
/**
* Checks to see if a VM exists
*
* @param vmName Name of the Velocimacro.
* @param templateName Template on which to look for the Macro.
* @return True if VM by that name exists, false if not
* @see RuntimeInstance#isVelocimacro(String, String)
*/
public static boolean isVelocimacro( String vmName, String templateName )
{
return ri.isVelocimacro( vmName, templateName );
}
/**
* tells the vmFactory to dump the specified namespace. This is to support
* clearing the VM list when in inline-VM-local-scope mode
* @param namespace Namespace to dump.
* @return True if namespace was dumped successfully.
* @see RuntimeInstance#dumpVMNamespace(String)
*/
public static boolean dumpVMNamespace( String namespace )
{
return ri.dumpVMNamespace( namespace );
}
/* --------------------------------------------------------------------
* R U N T I M E A C C E S S O R M E T H O D S
* --------------------------------------------------------------------
* These are the getXXX() methods that are a simple wrapper
* around the configuration object. This is an attempt
* to make a the Velocity Runtime the single access point
* for all things Velocity, and allow the Runtime to
* adhere as closely as possible the the Mediator pattern
* which is the ultimate goal.
* --------------------------------------------------------------------
*/
/**
* String property accessor method to hide the configuration implementation
* @param key property key
* @return value of key or null
* @see RuntimeInstance#getString(String)
*/
public static String getString(String key)
{
return ri.getString( key );
}
/**
* Int property accessor method to hide the configuration implementation.
*
* @param key Property key
* @return value
* @see RuntimeInstance#getInt(String)
*/
public static int getInt( String key )
{
return ri.getInt( key );
}
/**
* Int property accessor method to hide the configuration implementation.
*
* @param key property key
* @param defaultValue The default value.
* @return value
* @see RuntimeInstance#getInt(String, int)
*/
public static int getInt( String key, int defaultValue )
{
return ri.getInt( key, defaultValue );
}
/**
* Boolean property accessor method to hide the configuration implementation.
*
* @param key property key
* @param def The default value if property not found.
* @return value of key or default value
* @see RuntimeInstance#getBoolean(String, boolean)
*/
public static boolean getBoolean( String key, boolean def )
{
return ri.getBoolean( key, def );
}
/**
* Return the velocity runtime configuration object.
*
* @return ExtendedProperties configuration object which houses
* the velocity runtime properties.
* @see RuntimeInstance#getConfiguration()
*/
public static ExtendedProperties getConfiguration()
{
return ri.getConfiguration();
}
/**
* Return the Introspector for this RuntimeInstance
*
* @return Introspector object for this runtime instance
* @see RuntimeInstance#getIntrospector()
*/
public static Introspector getIntrospector()
{
return ri.getIntrospector();
}
/**
* Returns the event handlers for the application.
* @return The event handlers for the application.
* @see RuntimeInstance#getApplicationEventCartridge()
* @since 1.5
*/
public EventCartridge getEventCartridge()
{
return ri.getApplicationEventCartridge();
}
/**
* Gets the application attribute for the given key
*
* @see org.apache.velocity.runtime.RuntimeServices#getApplicationAttribute(Object)
* @param key
* @return The application attribute for the given key.
* @see RuntimeInstance#getApplicationAttribute(Object)
*/
public static Object getApplicationAttribute(Object key)
{
return ri.getApplicationAttribute(key);
}
/**
* Returns the Uberspect object for this Instance.
*
* @return The Uberspect object for this Instance.
* @see org.apache.velocity.runtime.RuntimeServices#getUberspect()
* @see RuntimeInstance#getUberspect()
*/
public static Uberspect getUberspect()
{
return ri.getUberspect();
}
/**
* @deprecated Use getRuntimeServices() instead.
* @return The RuntimeInstance used by this Singleton.
*/
public static RuntimeInstance getRuntimeInstance()
{
return ri;
}
}