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.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.io.StringReader;
import java.io.Writer;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Map;
import java.util.Properties;
import org.apache.commons.collections.ExtendedProperties;
import org.apache.commons.lang.text.StrBuilder;
import org.apache.velocity.Template;
import org.apache.velocity.app.event.EventCartridge;
import org.apache.velocity.app.event.EventHandler;
import org.apache.velocity.app.event.IncludeEventHandler;
import org.apache.velocity.app.event.InvalidReferenceEventHandler;
import org.apache.velocity.app.event.MethodExceptionEventHandler;
import org.apache.velocity.app.event.NullSetEventHandler;
import org.apache.velocity.app.event.ReferenceInsertionEventHandler;
import org.apache.velocity.context.Context;
import org.apache.velocity.context.InternalContextAdapterImpl;
import org.apache.velocity.exception.MethodInvocationException;
import org.apache.velocity.exception.ParseErrorException;
import org.apache.velocity.exception.ResourceNotFoundException;
import org.apache.velocity.exception.TemplateInitException;
import org.apache.velocity.exception.VelocityException;
import org.apache.velocity.runtime.directive.Directive;
import org.apache.velocity.runtime.log.Log;
import org.apache.velocity.runtime.log.LogManager;
import org.apache.velocity.runtime.parser.ParseException;
import org.apache.velocity.runtime.parser.Parser;
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.runtime.resource.ResourceManager;
import org.apache.velocity.util.ClassUtils;
import org.apache.velocity.util.RuntimeServicesAware;
import org.apache.velocity.util.StringUtils;
import org.apache.velocity.util.introspection.Introspector;
import org.apache.velocity.util.introspection.Uberspect;
import org.apache.velocity.util.introspection.UberspectLoggable;
import org.apache.velocity.util.introspection.ChainableUberspector;
import org.apache.velocity.util.introspection.LinkingUberspector;
/**
* 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:
*
* <blockquote><code><pre>
* ri.setProperty(Runtime.FILE_RESOURCE_LOADER_PATH, templatePath);
* ri.setProperty(Runtime.RUNTIME_LOG, pathToVelocityLog);
* ri.init();
* </pre></code></blockquote>
*
* <pre>
* -----------------------------------------------------------------------
* 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.
* -----------------------------------------------------------------------
* </pre>
*
* @author <a href="mailto:[email protected]">Jason van Zyl</a>
* @author <a href="mailto:[email protected]">Jeff Bowden</a>
* @author <a href="mailto:[email protected]">Geir Magusson Jr.</a>
* @version $Id: RuntimeInstance.java 896109 2010-01-05 15:59:48Z nbubna $
*/
public class RuntimeInstance implements RuntimeConstants, RuntimeServices
{
/**
* VelocimacroFactory object to manage VMs
*/
private VelocimacroFactory vmFactory = null;
/**
* The Runtime logger. We start with an instance of
* a 'primordial logger', which just collects log messages
* then, when the log system is initialized, all the
* messages get dumpted out of the primordial one into the real one.
*/
private Log log = new Log();
/**
* The Runtime parser pool
*/
private ParserPool parserPool;
/**
* Indicate whether the Runtime is in the midst of initialization.
*/
private boolean initializing = false;
/**
* Indicate whether the Runtime has been fully initialized.
*/
private volatile boolean initialized = false;
/**
* These are the properties that are laid down over top
* of the default properties when requested.
*/
private ExtendedProperties overridingProperties = null;
/**
* 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.
*/
private Hashtable runtimeDirectives;
/**
* 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.
*/
private ExtendedProperties configuration = new ExtendedProperties();
private ResourceManager resourceManager = null;
/**
* This stores the engine-wide set of event handlers. Event handlers for
* each specific merge are stored in the context.
*/
private EventCartridge eventCartridge = null;
/*
* Each runtime instance has it's own introspector
* to ensure that each instance is completely separate.
*/
private Introspector introspector = null;
/*
* Opaque reference to something specificed by the
* application for use in application supplied/specified
* pluggable components
*/
private Map applicationAttributes = null;
private Uberspect uberSpect;
private String encoding;
/**
* Creates a new RuntimeInstance object.
*/
public RuntimeInstance()
{
/*
* create a VM factory, introspector, and application attributes
*/
vmFactory = new VelocimacroFactory( this );
/*
* make a new introspector and initialize it
*/
introspector = new Introspector(getLog());
/*
* and a store for the application attributes
*/
applicationAttributes = new HashMap();
}
/**
* This is the primary initialization method in the Velocity
* Runtime. The systems that are setup/initialized here are
* as follows:
*
* <ul>
* <li>Logging System</li>
* <li>ResourceManager</li>
* <li>EventHandler</li>
* <li>Parser Pool</li>
* <li>Global Cache</li>
* <li>Static Content Include System</li>
* <li>Velocimacro System</li>
* </ul>
* @throws Exception When an error occured during initialization.
*/
public synchronized void init()
throws Exception
{
if (!initialized && !initializing)
{
initializing = true;
log.trace("*******************************************************************");
log.debug("Starting Apache Velocity v1.6.4 (compiled: 2010-04-27 15:31:23)");
log.trace("RuntimeInstance initializing.");
initializeProperties();
initializeLog();
initializeResourceManager();
initializeDirectives();
initializeEventHandlers();
initializeParserPool();
initializeIntrospection();
/*
* initialize the VM Factory. It will use the properties
* accessable from Runtime, so keep this here at the end.
*/
vmFactory.initVelocimacro();
log.trace("RuntimeInstance successfully initialized.");
initialized = true;
initializing = false;
}
}
/**
* Returns true if the RuntimeInstance has been successfully initialized.
* @return True if the RuntimeInstance has been successfully initialized.
* @since 1.5
*/
public boolean isInitialized()
{
return initialized;
}
/**
* Init or die! (with some log help, of course)
*/
private void requireInitialization()
{
if (!initialized)
{
log.debug("Velocity was not initialized! Calling init()...");
try
{
init();
}
catch (Exception e)
{
getLog().error("Could not auto-initialize Velocity", e);
throw new RuntimeException("Velocity could not be initialized!", e);
}
}
}
/**
* Gets the classname for the Uberspect introspection package and
* instantiates an instance.
*/
private void initializeIntrospection()
throws Exception
{
String[] uberspectors = configuration.getStringArray(RuntimeConstants.UBERSPECT_CLASSNAME);
for (int i=0; i <uberspectors.length;i++)
{
String rm = uberspectors[i];
Object o = null;
try
{
o = ClassUtils.getNewInstance( rm );
}
catch (ClassNotFoundException cnfe)
{
String err = "The specified class for Uberspect (" + rm
+ ") does not exist or is not accessible to the current classloader.";
log.error(err);
throw new Exception(err);
}
if (!(o instanceof Uberspect))
{
String err = "The specified class for Uberspect ("
+ rm + ") does not implement " + Uberspect.class.getName()
+ "; Velocity is not initialized correctly.";
log.error(err);
throw new Exception(err);
}
Uberspect u = (Uberspect)o;
if (u instanceof UberspectLoggable)
{
((UberspectLoggable)u).setLog(getLog());
}
if (u instanceof RuntimeServicesAware)
{
((RuntimeServicesAware)u).setRuntimeServices(this);
}
if (uberSpect == null)
{
uberSpect = u;
}
else
{
if (u instanceof ChainableUberspector)
{
((ChainableUberspector)u).wrap(uberSpect);
uberSpect = u;
}
else
{
uberSpect = new LinkingUberspector(uberSpect,u);
}
}
}
if(uberSpect != null)
{
uberSpect.init();
}
else
{
/*
* someone screwed up. Lets not fool around...
*/
String err = "It appears that no class was specified as the"
+ " Uberspect. Please ensure that all configuration"
+ " information is correct.";
log.error(err);
throw new Exception(err);
}
}
/**
* 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.
*/
private void setDefaultProperties()
{
InputStream inputStream = null;
try
{
inputStream = getClass()
.getResourceAsStream('/' + DEFAULT_RUNTIME_PROPERTIES);
configuration.load( inputStream );
if (log.isDebugEnabled())
{
log.debug("Default Properties File: " +
new File(DEFAULT_RUNTIME_PROPERTIES).getPath());
}
}
catch (IOException ioe)
{
String msg = "Cannot get Velocity Runtime default properties!";
log.error(msg, ioe);
throw new RuntimeException(msg, ioe);
}
finally
{
try
{
if (inputStream != null)
{
inputStream.close();
}
}
catch (IOException ioe)
{
String msg = "Cannot close Velocity Runtime default properties!";
log.error(msg, ioe);
throw new RuntimeException(msg, ioe);
}
}
}
/**
* Allows an external system to set a property in
* the Velocity Runtime.
*
* @param key property key
* @param value property value
*/
public void setProperty(String key, Object value)
{
if (overridingProperties == null)
{
overridingProperties = new ExtendedProperties();
}
overridingProperties.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
*/
public void setConfiguration( ExtendedProperties configuration)
{
if (overridingProperties == null)
{
overridingProperties = configuration;
}
else
{
// Avoid possible ConcurrentModificationException
if (overridingProperties != configuration)
{
overridingProperties.combine(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
*/
public void addProperty(String key, Object value)
{
if (overridingProperties == null)
{
overridingProperties = new ExtendedProperties();
}
overridingProperties.addProperty(key, value);
}
/**
* Clear the values pertaining to a particular
* property.
*
* @param key of property to clear
*/
public void clearProperty(String key)
{
if (overridingProperties != null)
{
overridingProperties.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.
*/
public Object getProperty(String key)
{
Object o = null;
/**
* Before initialization, check the user-entered properties first.
*/
if (!initialized && !initializing && overridingProperties != null)
{
o = overridingProperties.get(key);
}
/**
* After initialization, configuration will hold all properties.
*/
if (o == null)
{
o = configuration.getProperty(key);
}
if (o instanceof String)
{
return StringUtils.nullTrim((String) o);
}
else
{
return o;
}
}
/**
* 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.
*/
private void initializeProperties()
{
/*
* Always lay down the default properties first as
* to provide a solid base.
*/
if (configuration.isInitialized() == false)
{
setDefaultProperties();
}
if( overridingProperties != null)
{
configuration.combine(overridingProperties);
}
}
/**
* Initialize the Velocity Runtime with a Properties
* object.
*
* @param p
* @throws Exception When an error occurs during initialization.
*/
public void init(Properties p) throws Exception
{
setProperties(ExtendedProperties.convertProperties(p));
init();
}
private void setProperties(ExtendedProperties p)
{
if (overridingProperties == null)
{
overridingProperties = p;
}
else
{
overridingProperties.combine(p);
}
}
/**
* Initialize the Velocity Runtime with the name of
* ExtendedProperties object.
*
* @param configurationFile
* @throws Exception When an error occurs during initialization.
*/
public void init(String configurationFile)
throws Exception
{
setProperties(new ExtendedProperties(configurationFile));
init();
}
private void initializeResourceManager()
throws Exception
{
/*
* Which resource manager?
*/
String rm = getString(RuntimeConstants.RESOURCE_MANAGER_CLASS);
if (rm != null && rm.length() > 0)
{
/*
* if something was specified, then make one.
* if that isn't a ResourceManager, consider
* this a huge error and throw
*/
Object o = null;
try
{
o = ClassUtils.getNewInstance( rm );
}
catch (ClassNotFoundException cnfe )
{
String err = "The specified class for ResourceManager (" + rm
+ ") does not exist or is not accessible to the current classloader.";
log.error(err);
throw new Exception(err);
}
if (!(o instanceof ResourceManager))
{
String err = "The specified class for ResourceManager (" + rm
+ ") does not implement " + ResourceManager.class.getName()
+ "; Velocity is not initialized correctly.";
log.error(err);
throw new Exception(err);
}
resourceManager = (ResourceManager) o;
resourceManager.initialize(this);
}
else
{
/*
* someone screwed up. Lets not fool around...
*/
String err = "It appears that no class was specified as the"
+ " ResourceManager. Please ensure that all configuration"
+ " information is correct.";
log.error(err);
throw new Exception( err );
}
}
private void initializeEventHandlers()
throws Exception
{
eventCartridge = new EventCartridge();
/**
* For each type of event handler, get the class name, instantiate it, and store it.
*/
String[] referenceinsertion = configuration.getStringArray(RuntimeConstants.EVENTHANDLER_REFERENCEINSERTION);
if ( referenceinsertion != null )
{
for ( int i=0; i < referenceinsertion.length; i++ )
{
EventHandler ev = initializeSpecificEventHandler(referenceinsertion[i],RuntimeConstants.EVENTHANDLER_REFERENCEINSERTION,ReferenceInsertionEventHandler.class);
if (ev != null)
eventCartridge.addReferenceInsertionEventHandler((ReferenceInsertionEventHandler) ev);
}
}
String[] nullset = configuration.getStringArray(RuntimeConstants.EVENTHANDLER_NULLSET);
if ( nullset != null )
{
for ( int i=0; i < nullset.length; i++ )
{
EventHandler ev = initializeSpecificEventHandler(nullset[i],RuntimeConstants.EVENTHANDLER_NULLSET,NullSetEventHandler.class);
if (ev != null)
eventCartridge.addNullSetEventHandler((NullSetEventHandler) ev);
}
}
String[] methodexception = configuration.getStringArray(RuntimeConstants.EVENTHANDLER_METHODEXCEPTION);
if ( methodexception != null )
{
for ( int i=0; i < methodexception.length; i++ )
{
EventHandler ev = initializeSpecificEventHandler(methodexception[i],RuntimeConstants.EVENTHANDLER_METHODEXCEPTION,MethodExceptionEventHandler.class);
if (ev != null)
eventCartridge.addMethodExceptionHandler((MethodExceptionEventHandler) ev);
}
}
String[] includeHandler = configuration.getStringArray(RuntimeConstants.EVENTHANDLER_INCLUDE);
if ( includeHandler != null )
{
for ( int i=0; i < includeHandler.length; i++ )
{
EventHandler ev = initializeSpecificEventHandler(includeHandler[i],RuntimeConstants.EVENTHANDLER_INCLUDE,IncludeEventHandler.class);
if (ev != null)
eventCartridge.addIncludeEventHandler((IncludeEventHandler) ev);
}
}
String[] invalidReferenceSet = configuration.getStringArray(RuntimeConstants.EVENTHANDLER_INVALIDREFERENCES);
if ( invalidReferenceSet != null )
{
for ( int i=0; i < invalidReferenceSet.length; i++ )
{
EventHandler ev = initializeSpecificEventHandler(invalidReferenceSet[i],RuntimeConstants.EVENTHANDLER_INVALIDREFERENCES,InvalidReferenceEventHandler.class);
if (ev != null)
{
eventCartridge.addInvalidReferenceEventHandler((InvalidReferenceEventHandler) ev);
}
}
}
}
private EventHandler initializeSpecificEventHandler(String classname, String paramName, Class EventHandlerInterface)
throws Exception
{
if ( classname != null && classname.length() > 0)
{
Object o = null;
try {
o = ClassUtils.getNewInstance(classname);
}
catch (ClassNotFoundException cnfe )
{
String err = "The specified class for "
+ paramName + " (" + classname
+ ") does not exist or is not accessible to the current classloader.";
log.error(err);
throw new Exception(err);
}
if (!EventHandlerInterface.isAssignableFrom(EventHandlerInterface))
{
String err = "The specified class for " + paramName + " ("
+ classname + ") does not implement "
+ EventHandlerInterface.getName()
+ "; Velocity is not initialized correctly.";
log.error(err);
throw new Exception(err);
}
EventHandler ev = (EventHandler) o;
if ( ev instanceof RuntimeServicesAware )
((RuntimeServicesAware) ev).setRuntimeServices(this);
return ev;
} else
return null;
}
/**
* Initialize the Velocity logging system.
*
* @throws Exception
*/
private void initializeLog() throws Exception
{
// since the Log we started with was just placeholding,
// let's update it with the real LogChute settings.
LogManager.updateLog(this.log, this);
}
/**
* 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 Exception
*/
private void initializeDirectives()
throws Exception
{
/*
* Initialize the runtime directive table.
* This will be used for creating parsers.
*/
runtimeDirectives = new Hashtable();
Properties directiveProperties = new Properties();
/*
* Grab the properties file with the list of directives
* that we should initialize.
*/
InputStream inputStream = null;
try
{
inputStream = getClass().getResourceAsStream('/' + DEFAULT_RUNTIME_DIRECTIVES);
if (inputStream == null)
{
throw new Exception("Error loading directive.properties! " +
"Something is very wrong if these properties " +
"aren't being located. Either your Velocity " +
"distribution is incomplete or your Velocity " +
"jar file is corrupted!");
}
directiveProperties.load(inputStream);
}
catch (IOException ioe)
{
String msg = "Error while loading directive properties!";
log.error(msg, ioe);
throw new RuntimeException(msg, ioe);
}
finally
{
try
{
if (inputStream != null)
{
inputStream.close();
}
}
catch (IOException ioe)
{
String msg = "Cannot close directive properties!";
log.error(msg, ioe);
throw new RuntimeException(msg, ioe);
}
}
/*
* Grab all the values of the properties. These
* are all class names for example:
*
* org.apache.velocity.runtime.directive.Foreach
*/
Enumeration directiveClasses = directiveProperties.elements();
while (directiveClasses.hasMoreElements())
{
String directiveClass = (String) directiveClasses.nextElement();
loadDirective(directiveClass);
log.debug("Loaded System Directive: " + directiveClass);
}
/*
* now the user's directives
*/
String[] userdirective = configuration.getStringArray("userdirective");
for( int i = 0; i < userdirective.length; i++)
{
loadDirective(userdirective[i]);
if (log.isDebugEnabled())
{
log.debug("Loaded User Directive: " + userdirective[i]);
}
}
}
/**
* Programatically add a directive.
* @param directive
*/
public void addDirective(Directive directive)
{
runtimeDirectives.put(directive.getName(), directive);
}
/**
* Retrieve a previously instantiated directive.
* @param name name of the directive
* @return the {@link Directive} for that name
*/
public Directive getDirective(String name)
{
return (Directive) runtimeDirectives.get(name);
}
/**
* Remove a directive.
* @param name name of the directive.
*/
public void removeDirective(String name)
{
runtimeDirectives.remove(name);
}
/**
* instantiates and loads the directive with some basic checks
*
* @param directiveClass classname of directive to load
*/
private void loadDirective(String directiveClass)
{
try
{
Object o = ClassUtils.getNewInstance( directiveClass );
if (o instanceof Directive)
{
Directive directive = (Directive) o;
addDirective(directive);
}
else
{
String msg = directiveClass + " does not implement "
+ Directive.class.getName() + "; it cannot be loaded.";
log.error(msg);
throw new VelocityException(msg);
}
}
// The ugly threesome: ClassNotFoundException,
// IllegalAccessException, InstantiationException.
// Ignore Findbugs complaint for now.
catch (Exception e)
{
String msg = "Failed to load Directive: " + directiveClass;
log.error(msg, e);
throw new VelocityException(msg, e);
}
}
/**
* Initializes the Velocity parser pool.
*/
private void initializeParserPool() throws Exception
{
/*
* Which parser pool?
*/
String pp = getString(RuntimeConstants.PARSER_POOL_CLASS);
if (pp != null && pp.length() > 0)
{
/*
* if something was specified, then make one.
* if that isn't a ParserPool, consider
* this a huge error and throw
*/
Object o = null;
try
{
o = ClassUtils.getNewInstance( pp );
}
catch (ClassNotFoundException cnfe )
{
String err = "The specified class for ParserPool ("
+ pp
+ ") does not exist (or is not accessible to the current classloader.";
log.error(err);
throw new Exception(err);
}
if (!(o instanceof ParserPool))
{
String err = "The specified class for ParserPool ("
+ pp + ") does not implement " + ParserPool.class
+ " Velocity not initialized correctly.";
log.error(err);
throw new Exception(err);
}
parserPool = (ParserPool) o;
parserPool.initialize(this);
}
else
{
/*
* someone screwed up. Lets not fool around...
*/
String err = "It appears that no class was specified as the"
+ " ParserPool. Please ensure that all configuration"
+ " information is correct.";
log.error(err);
throw new Exception( err );
}
}
/**
* Returns a JavaCC generated Parser.
*
* @return Parser javacc generated parser
*/
public Parser createNewParser()
{
requireInitialization();
Parser parser = new Parser(this);
parser.setDirectives(runtimeDirectives);
return parser;
}
/**
* Parse the input and return the root of
* AST node structure.
* <br><br>
* 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 string String to be parsed
* @param templateName name of the template being parsed
* @return A root node representing the template as an AST tree.
* @throws ParseException When the string could not be parsed as a template.
* @since 1.6
*/
public SimpleNode parse(String string, String templateName)
throws ParseException
{
return parse(new StringReader(string), templateName);
}
/**
* Parse the input and return the root of
* AST node structure.
* <br><br>
* 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.
*/
public SimpleNode parse(Reader reader, String templateName)
throws ParseException
{
/*
* do it and dump the VM namespace for this template
*/
return parse(reader, templateName, true);
}
/**
* 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.
*/
public SimpleNode parse(Reader reader, String templateName, boolean dumpNamespace)
throws ParseException
{
requireInitialization();
Parser parser = (Parser) parserPool.get();
boolean keepParser = true;
if (parser == null)
{
/*
* if we couldn't get a parser from the pool make one and log it.
*/
if (log.isInfoEnabled())
{
log.info("Runtime : ran out of parsers. Creating a new one. "
+ " Please increment the parser.pool.size property."
+ " The current value is too small.");
}
parser = createNewParser();
keepParser = false;
}
try
{
/*
* dump namespace if we are told to. Generally, you want to
* do this - you don't in special circumstances, such as
* when a VM is getting init()-ed & parsed
*/
if (dumpNamespace)
{
dumpVMNamespace(templateName);
}
return parser.parse(reader, templateName);
}
finally
{
if (keepParser)
{
parserPool.put(parser);
}
}
}
/**
* Renders the input string using the context into the output writer.
* To be used when a template is dynamically constructed, or want to use
* Velocity as a token replacer.
*
* @param context context to use in rendering input string
* @param out Writer in which to render the output
* @param logTag string to be used as the template name for log
* messages in case of error
* @param instring input string containing the VTL to be rendered
*
* @return true if successful, false otherwise. If false, see
* Velocity runtime log
* @throws ParseErrorException The template could not be parsed.
* @throws MethodInvocationException A method on a context object could not be invoked.
* @throws ResourceNotFoundException A referenced resource could not be loaded.
* @throws IOException While rendering to the writer, an I/O problem occured.
* @since Velocity 1.6
*/
public boolean evaluate(Context context, Writer out,
String logTag, String instring) throws IOException
{
return evaluate(context, out, logTag, new StringReader(instring));
}
/**
* Renders the input reader using the context into the output writer.
* To be used when a template is dynamically constructed, or want to
* use Velocity as a token replacer.
*
* @param context context to use in rendering input string
* @param writer Writer in which to render the output
* @param logTag string to be used as the template name for log messages
* in case of error
* @param reader Reader containing the VTL to be rendered
*
* @return true if successful, false otherwise. If false, see
* Velocity runtime log
* @throws ParseErrorException The template could not be parsed.
* @throws MethodInvocationException A method on a context object could not be invoked.
* @throws ResourceNotFoundException A referenced resource could not be loaded.
* @throws IOException While reading from the reader or rendering to the writer,
* an I/O problem occured.
* @since Velocity 1.6
*/
public boolean evaluate(Context context, Writer writer,
String logTag, Reader reader) throws IOException
{
if (logTag == null)
{
throw new NullPointerException("logTag (i.e. template name) cannot be null, you must provide an identifier for the content being evaluated");
}
SimpleNode nodeTree = null;
try
{
nodeTree = parse(reader, logTag);
}
catch (ParseException pex)
{
throw new ParseErrorException(pex);
}
catch (TemplateInitException pex)
{
throw new ParseErrorException(pex);
}
if (nodeTree == null)
{
return false;
}
else
{
return render(context, writer, logTag, nodeTree);
}
}
/**
* Initializes and renders the AST {@link SimpleNode} using the context
* into the output writer.
*
* @param context context to use in rendering input string
* @param writer Writer in which to render the output
* @param logTag string to be used as the template name for log messages
* in case of error
* @param nodeTree SimpleNode which is the root of the AST to be rendered
*
* @return true if successful, false otherwise. If false, see
* Velocity runtime log for errors
* @throws ParseErrorException The template could not be parsed.
* @throws MethodInvocationException A method on a context object could not be invoked.
* @throws ResourceNotFoundException A referenced resource could not be loaded.
* @throws IOException While rendering to the writer, an I/O problem occured.
* @since Velocity 1.6
*/
public boolean render(Context context, Writer writer,
String logTag, SimpleNode nodeTree) throws IOException
{
/*
* we want to init then render
*/
InternalContextAdapterImpl ica =
new InternalContextAdapterImpl(context);
ica.pushCurrentTemplateName(logTag);
try
{
try
{
nodeTree.init(ica, this);
}
catch (TemplateInitException pex)
{
throw new ParseErrorException(pex);
}
/**
* pass through application level runtime exceptions
*/
catch(RuntimeException e)
{
throw e;
}
catch(Exception e)
{
String msg = "RuntimeInstance.render(): init exception for tag = "+logTag;
getLog().error(msg, e);
throw new VelocityException(msg, e);
}
/*
* now render, and let any exceptions fly
*/
nodeTree.render(ica, writer);
}
finally
{
ica.popCurrentTemplateName();
}
return true;
}
/**
* Invokes a currently registered Velocimacro with the params provided
* and places the rendered stream into the writer.
* <br>
* Note : currently only accepts args to the VM if they are in the context.
*
* @param vmName name of Velocimacro to call
* @param logTag string to be used for template name in case of error. if null,
* the vmName will be used
* @param params keys for args used to invoke Velocimacro, in java format
* rather than VTL (eg "foo" or "bar" rather than "$foo" or "$bar")
* @param context Context object containing data/objects used for rendering.
* @param writer Writer for output stream
* @return true if Velocimacro exists and successfully invoked, false otherwise.
* @throws IOException While rendering to the writer, an I/O problem occured.
* @since 1.6
*/
public boolean invokeVelocimacro(final String vmName, String logTag,
String[] params, final Context context,
final Writer writer)
throws IOException
{
/* check necessary parameters */
if (vmName == null || context == null || writer == null)
{
String msg = "RuntimeInstance.invokeVelocimacro() : invalid call : vmName, context, and writer must not be null";
getLog().error(msg);
throw new NullPointerException(msg);
}
/* handle easily corrected parameters */
if (logTag == null)
{
logTag = vmName;
}
if (params == null)
{
params = new String[0];
}
/* does the VM exist? */
if (!isVelocimacro(vmName, logTag))
{
String msg = "RuntimeInstance.invokeVelocimacro() : VM '" + vmName
+ "' is not registered.";
getLog().error(msg);
throw new VelocityException(msg);
}
/* now just create the VM call, and use evaluate */
StrBuilder template = new StrBuilder("#");
template.append(vmName);
template.append("(");
for( int i = 0; i < params.length; i++)
{
template.append(" $");
template.append(params[i]);
}
template.append(" )");
return evaluate(context, writer, logTag, template.toString());
}
/**
* Retrieves and caches the configured default encoding
* for better performance. (VELOCITY-606)
*/
private String getDefaultEncoding()
{
if (encoding == null)
{
encoding = getString(INPUT_ENCODING, ENCODING_DEFAULT);
}
return encoding;
}
/**
* Returns a <code>Template</code> from the resource manager.
* This method assumes that the character encoding of the
* template is set by the <code>input.encoding</code>
* 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
*/
public Template getTemplate(String name)
throws ResourceNotFoundException, ParseErrorException, Exception
{
return getTemplate(name, getDefaultEncoding());
}
/**
* Returns a <code>Template</code> 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
*/
public Template getTemplate(String name, String encoding)
throws ResourceNotFoundException, ParseErrorException, Exception
{
requireInitialization();
return (Template)
resourceManager.getResource(name,
ResourceManager.RESOURCE_TEMPLATE, 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.
*/
public ContentResource getContent(String name)
throws ResourceNotFoundException, ParseErrorException, Exception
{
/*
* the encoding is irrelvant as we don't do any converstion
* the bytestream should be dumped to the output stream
*/
return getContent(name, getDefaultEncoding());
}
/**
* 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.
*/
public ContentResource getContent(String name, String encoding)
throws ResourceNotFoundException, ParseErrorException, Exception
{
requireInitialization();
return (ContentResource)
resourceManager.getResource(name,
ResourceManager.RESOURCE_CONTENT, encoding);
}
/**
* Determines if a template exists and returns name of the loader that
* provides it. This is a slightly less hokey way to support
* the Velocity.resourceExists() 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
*/
public String getLoaderNameForResource(String resourceName)
{
requireInitialization();
return resourceManager.getLoaderNameForResource(resourceName);
}
/**
* Returns a convenient Log instance that wraps the current LogChute.
* Use this to log error messages. It has the usual methods.
*
* @return A convenience Log instance that wraps the current LogChute.
* @since 1.5
*/
public Log getLog()
{
return log;
}
/**
* @deprecated Use getLog() and call warn() on it.
* @see Log#warn(Object)
* @param message The message to log.
*/
public 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 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 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 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
*/
public String getString( String key, String defaultValue)
{
return configuration.getString(key, defaultValue);
}
/**
* Returns the appropriate VelocimacroProxy object if vmName
* 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.
* @since 1.6
*/
public Directive getVelocimacro(String vmName, String templateName)
{
return vmFactory.getVelocimacro( vmName, templateName );
}
/**
* Returns the appropriate VelocimacroProxy object if vmName
* is a valid current Velocimacro.
*
* @param vmName Name of velocimacro requested
* @param templateName Name of the namespace.
* @param renderingTemplate Name of the template we are currently rendering. This
* information is needed when VM_PERM_ALLOW_INLINE_REPLACE_GLOBAL setting is true
* and template contains a macro with the same name as the global macro library.
*
* @since Velocity 1.6
*
* @return VelocimacroProxy
*/
public Directive getVelocimacro(String vmName, String templateName, String renderingTemplate)
{
return vmFactory.getVelocimacro( vmName, templateName, renderingTemplate );
}
/**
* 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.
*
* @deprecated Use addVelocimacro(String, Node, String[], String) instead
*
* @return True if added, false if rejected for some
* reason (either parameters or permission settings)
*/
public boolean addVelocimacro( String name,
String macro,
String argArray[],
String sourceTemplate )
{
return vmFactory.addVelocimacro(name, macro, argArray, sourceTemplate);
}
/**
* Adds a new Velocimacro. Usually called by Macro only while parsing.
*
* Called by org.apache.velocity.runtime.directive.processAndRegister
*
* @param name Name of velocimacro
* @param macro root AST node of the parsed macro
* @param argArray Array of strings, containing the
* #macro() arguments. the 0th is the name.
* @param sourceTemplate
*
* @since Velocity 1.6
*
* @return boolean True if added, false if rejected for some
* reason (either parameters or permission settings)
*/
public boolean addVelocimacro( String name,
Node macro,
String argArray[],
String sourceTemplate )
{
return vmFactory.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
*/
public boolean isVelocimacro( String vmName, String templateName )
{
return vmFactory.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.
*/
public boolean dumpVMNamespace(String namespace)
{
return vmFactory.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
*/
public String getString(String key)
{
return StringUtils.nullTrim(configuration.getString(key));
}
/**
* Int property accessor method to hide the configuration implementation.
*
* @param key Property key
* @return value
*/
public int getInt(String key)
{
return configuration.getInt(key);
}
/**
* Int property accessor method to hide the configuration implementation.
*
* @param key property key
* @param defaultValue The default value.
* @return value
*/
public int getInt(String key, int defaultValue)
{
return configuration.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
*/
public boolean getBoolean(String key, boolean def)
{
return configuration.getBoolean(key, def);
}
/**
* Return the velocity runtime configuration object.
*
* @return Configuration object which houses the Velocity runtime
* properties.
*/
public ExtendedProperties getConfiguration()
{
return configuration;
}
/**
* Return the Introspector for this instance
* @return The Introspector for this instance
*/
public Introspector getIntrospector()
{
return introspector;
}
/**
* Returns the event handlers for the application.
* @return The event handlers for the application.
* @since 1.5
*/
public EventCartridge getApplicationEventCartridge()
{
return eventCartridge;
}
/**
* Gets the application attribute for the given key
*
* @param key
* @return The application attribute for the given key.
*/
public Object getApplicationAttribute(Object key)
{
return applicationAttributes.get(key);
}
/**
* Sets the application attribute for the given key
*
* @param key
* @param o The new application attribute.
* @return The old value of this attribute or null if it hasn't been set before.
*/
public Object setApplicationAttribute(Object key, Object o)
{
return applicationAttributes.put(key, o);
}
/**
* Returns the Uberspect object for this Instance.
*
* @return The Uberspect object for this Instance.
*/
public Uberspect getUberspect()
{
return uberSpect;
}
}
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