Package org.apache.velocity.runtime

Class RuntimeSingleton

  • All Implemented Interfaces:
    DeprecatedRuntimeConstants, RuntimeConstants
    public class RuntimeSingleton
extends 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, which can make all needed setProperty() calls before calling init().

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 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 laid down
 first to provide a solid base, then any properties provided
 in the given properties object will override the corresponding
 default property.
 -----------------------------------------------------------------------
    Version:
    $Id$
    Author:
    Jason van Zyl, Jeff Bowden, Geir Magusson Jr., Daniel Rall
    See Also:
    RuntimeInstance

    • Constructor Detail

      • RuntimeSingleton

        public RuntimeSingleton()

    • Method Detail

      • init

        public static void init()
        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
        See Also:
        RuntimeInstance.init()

      • reset

        public static void reset()
        Resets the instance, so Velocity can be re-initialized again.
        Since:
        2.0.0

      • isInitialized

        public static boolean isInitialized()
        Returns true if the RuntimeInstance has been successfully initialized.
        Returns:
        True if the RuntimeInstance has been successfully initialized.
        Since:
        1.5
        See Also:
        RuntimeInstance.isInitialized()

      • getRuntimeServices

        public static RuntimeServices getRuntimeServices()
        Returns the RuntimeServices Instance used by this wrapper.
        Returns:
        The RuntimeServices Instance used by this wrapper.

      • setProperties

        public static void setProperties​(String propsFilename)
        Set an entire configuration at once from a named properties file
        Parameters:
        propsFilename - properties filename
        Since:
        2.1

      • addProperty

        public static void addProperty​(String key,
                               Object value)
        Add a property to the configuration. If it already exists then the value stated here will be added to the configuration entry. For example, if resource.loader = file is already present in the configuration and you addProperty("resource.loader", "classpath") Then you will end up with a Vector like the following: ["file", "classpath"]
        Parameters:
        key -
        value -
        See Also:
        RuntimeInstance.addProperty(String, Object)

      • getProperty

        public static Object getProperty​(String key)
        Allows an external caller to get a property. The calling routine is required to know the type, as this routine will return an Object, as that is what properties can be.
        Parameters:
        key - property to return
        Returns:
        Value of the property or null if it does not exist.
        See Also:
        RuntimeInstance.getProperty(String)

      • init

        public static void init​(String configurationFile)
        Initialize the Velocity Runtime with the name of a properties file.
        Parameters:
        configurationFile -
        See Also:
        RuntimeInstance.init(String)

      • parse

        public static SimpleNode parse​(Reader reader,
                               Template template)
                        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.
        Parameters:
        reader - Reader retrieved by a resource loader
        template - Template being parsed
        Returns:
        A root node representing the template as an AST tree.
        Throws:
        ParseException - When the template could not be parsed.
        See Also:
        RuntimeInstance.parse(Reader, Template)

      • getLoaderNameForResource

        public static String getLoaderNameForResource​(String resourceName)
        Determines is a template exists, and returns name of the loader that provides it. This is a slightly less hokey way to support the Velocity.templateExists() utility method, which was broken when per-template encoding was introduced. We can revisit this.
        Parameters:
        resourceName - Name of template or content resource
        Returns:
        class name of loader than can provide it
        See Also:
        RuntimeInstance.getLoaderNameForResource(String)

      • getLog

        public static org.slf4j.Logger getLog()
        Returns the configured logger.
        Returns:
        A Logger instance
        Since:
        1.5
        See Also:
        RuntimeInstance.getLog()

      • getString

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

      • getVelocimacro

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

      • addVelocimacro

        public static boolean addVelocimacro​(String name,
                                     Node macro,
                                     List<Macro.MacroArg> macroArgs,
                                     Template definingTemplate)
        Adds a new Velocimacro. Usually called by Macro only while parsing.
        Parameters:
        name - Name of a new velocimacro.
        macro - root AST node of the parsed macro
        macroArgs - Array of macro arguments, containing the #macro() arguments and default values. the 0th is the name.
        definingTemplate - Template containing the definition of the macro.
        Returns:
        true for success

      • isVelocimacro

        public static boolean isVelocimacro​(String vmName,
                                    Template template)
        Checks to see if a VM exists
        Parameters:
        vmName - Name of the Velocimacro.
        template - Template on which to look for the Macro.
        Returns:
        True if VM by that name exists, false if not

      • getString

        public static String getString​(String key)
        String property accessor method to hide the configuration implementation
        Parameters:
        key - property key
        Returns:
        value of key or null
        See Also:
        RuntimeInstance.getString(String)

      • getInt

        public static int getInt​(String key)
        Int property accessor method to hide the configuration implementation.
        Parameters:
        key - Property key
        Returns:
        value
        See Also:
        RuntimeInstance.getInt(String)

      • getInt

        public static int getInt​(String key,
                         int defaultValue)
        Int property accessor method to hide the configuration implementation.
        Parameters:
        key - property key
        defaultValue - The default value.
        Returns:
        value
        See Also:
        RuntimeInstance.getInt(String, int)

      • getBoolean

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

      • getConfiguration

        public static ExtProperties getConfiguration()
        Return the velocity runtime configuration object.
        Returns:
        ExtProperties configuration object which houses the velocity runtime properties.
        See Also:
        RuntimeInstance.getConfiguration()

      • removeDirective

        public static void removeDirective​(String name)
        Remove a directive.
        Parameters:
        name - name of the directive.

      • loadDirective

        public static void loadDirective​(String directiveClass)
        Instantiates and loads the directive with some basic checks.
        Parameters:
        directiveClass - classname of directive to load