Class BSFManager


  • public class BSFManager
    extends java.lang.Object
    This class is the entry point to the bean scripting framework. An application wishing to integrate scripting to a Java app would place an instance of a BSFManager in their code and use its services to register the beans they want to make available for scripting, load scripting engines, and run scripts.

    BSFManager serves as the registry of available scripting engines as well. Loading and unloading of scripting engines is supported as well. Each BSFManager loads one engine per language. Several BSFManagers can be created per JVM.

    Author:
    Sanjiva Weerawarana, Matthew J. Duftler, Sam Ruby, Olivier Gruber (added original debugging support), Don Schwarz (added support for registering languages dynamically)
    • Constructor Summary

      Constructors 
      Constructor Description
      BSFManager()  
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.Object apply​(java.lang.String lang, java.lang.String source, int lineNo, int columnNo, java.lang.Object funcBody, java.util.Vector paramNames, java.util.Vector arguments)
      Apply the given anonymous function of the given language to the given parameters and return the resulting value.
      void compileApply​(java.lang.String lang, java.lang.String source, int lineNo, int columnNo, java.lang.Object funcBody, java.util.Vector paramNames, java.util.Vector arguments, CodeBuffer cb)
      Compile the application of the given anonymous function of the given language to the given parameters into the given CodeBuffer.
      void compileExpr​(java.lang.String lang, java.lang.String source, int lineNo, int columnNo, java.lang.Object expr, CodeBuffer cb)
      Compile the given expression of the given language into the given CodeBuffer.
      void compileScript​(java.lang.String lang, java.lang.String source, int lineNo, int columnNo, java.lang.Object script, CodeBuffer cb)
      Compile the given script of the given language into the given CodeBuffer.
      void declareBean​(java.lang.String beanName, java.lang.Object bean, java.lang.Class type)
      Declare a bean.
      java.lang.Object eval​(java.lang.String lang, java.lang.String source, int lineNo, int columnNo, java.lang.Object expr)
      Evaluate the given expression of the given language and return the resulting value.
      void exec​(java.lang.String lang, java.lang.String source, int lineNo, int columnNo, java.lang.Object script)
      Execute the given script of the given language.
      java.lang.ClassLoader getClassLoader()
      Get classLoader
      java.lang.String getClassPath()
      Get classPath
      static java.lang.String getLangFromFilename​(java.lang.String fileName)
      Determine the language of a script file by looking at the file extension.
      ObjectRegistry getObjectRegistry()
      Return the current object registry of the manager.
      java.lang.String getTempDir()
      Get tempDir
      static java.lang.String getVersion()
      Returns the version string of BSF.
      void iexec​(java.lang.String lang, java.lang.String source, int lineNo, int columnNo, java.lang.Object script)
      Execute the given script of the given language, attempting to emulate an interactive session w/ the language.
      static boolean isLanguageRegistered​(java.lang.String lang)
      Determine whether a language is registered.
      BSFEngine loadScriptingEngine​(java.lang.String lang)
      Load a scripting engine based on the lang string identifying it.
      java.lang.Object lookupBean​(java.lang.String beanName)
      return a handle to a bean registered in the bean registry by the application or a scripting engine.
      void registerBean​(java.lang.String beanName, java.lang.Object bean)
      Registering a bean allows a scripting engine or the application to access that bean by name and to manipulate it.
      static void registerScriptingEngine​(java.lang.String lang, java.lang.String engineClassName, java.lang.String[] extensions)
      Register a scripting engine in the static registry of the BSFManager.
      void setClassLoader​(java.lang.ClassLoader classLoader)
      Set the class loader for those that need to use it.
      void setClassPath​(java.lang.String classPath)
      Set the classpath for those that need to use it.
      void setObjectRegistry​(ObjectRegistry objectRegistry)
      Set the object registry used by this manager.
      void setTempDir​(java.lang.String tempDir)
      Temporary directory to put stuff into (for those who need to).
      void terminate()
      Gracefully terminate all engines
      void undeclareBean​(java.lang.String beanName)
      Undeclare a previously declared bean.
      void unregisterBean​(java.lang.String beanName)
      Unregister a previously registered bean.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • version

        protected static java.lang.String version
      • registeredEngines

        protected static java.util.Hashtable registeredEngines
      • extn2Lang

        protected static java.util.Hashtable extn2Lang
      • loadedEngines

        protected java.util.Hashtable loadedEngines
      • pcs

        protected java.beans.PropertyChangeSupport pcs
      • classLoader

        protected java.lang.ClassLoader classLoader
      • tempDir

        protected java.lang.String tempDir
      • classPath

        protected java.lang.String classPath
      • declaredBeans

        protected java.util.Vector declaredBeans
    • Constructor Detail

      • BSFManager

        public BSFManager()
    • Method Detail

      • getVersion

        public static java.lang.String getVersion()
        Returns the version string of BSF.
        Returns:
        version string in the form "abc.yyyymmdd" where "abc" represents a dewey decimal number (three levels, each between 0 and 9), and "yyyy" a four digit year, "mm" a two digit month, "dd" a two digit day.
        Example: "240.20061006" stands for: BSF version 2.4.0 as of 2006-10-06.
        Since:
        2006-01-17
      • apply

        public java.lang.Object apply​(java.lang.String lang,
                                      java.lang.String source,
                                      int lineNo,
                                      int columnNo,
                                      java.lang.Object funcBody,
                                      java.util.Vector paramNames,
                                      java.util.Vector arguments)
                               throws BSFException
        Apply the given anonymous function of the given language to the given parameters and return the resulting value.
        Parameters:
        lang - language identifier
        source - (context info) the source of this expression (e.g., filename)
        lineNo - (context info) the line number in source for expr
        columnNo - (context info) the column number in source for expr
        funcBody - the multi-line, value returning script to evaluate
        paramNames - the names of the parameters above assumes
        arguments - values of the above parameters
        Throws:
        BSFException - if anything goes wrong while running the script
      • compileApply

        public void compileApply​(java.lang.String lang,
                                 java.lang.String source,
                                 int lineNo,
                                 int columnNo,
                                 java.lang.Object funcBody,
                                 java.util.Vector paramNames,
                                 java.util.Vector arguments,
                                 CodeBuffer cb)
                          throws BSFException
        Compile the application of the given anonymous function of the given language to the given parameters into the given CodeBuffer.
        Parameters:
        lang - language identifier
        source - (context info) the source of this expression (e.g., filename)
        lineNo - (context info) the line number in source for expr
        columnNo - (context info) the column number in source for expr
        funcBody - the multi-line, value returning script to evaluate
        paramNames - the names of the parameters above assumes
        arguments - values of the above parameters
        cb - code buffer to compile into
        Throws:
        BSFException - if anything goes wrong while running the script
      • compileExpr

        public void compileExpr​(java.lang.String lang,
                                java.lang.String source,
                                int lineNo,
                                int columnNo,
                                java.lang.Object expr,
                                CodeBuffer cb)
                         throws BSFException
        Compile the given expression of the given language into the given CodeBuffer.
        Parameters:
        lang - language identifier
        source - (context info) the source of this expression (e.g., filename)
        lineNo - (context info) the line number in source for expr
        columnNo - (context info) the column number in source for expr
        expr - the expression to compile
        cb - code buffer to compile into
        Throws:
        BSFException - if any error while compiling the expression
      • compileScript

        public void compileScript​(java.lang.String lang,
                                  java.lang.String source,
                                  int lineNo,
                                  int columnNo,
                                  java.lang.Object script,
                                  CodeBuffer cb)
                           throws BSFException
        Compile the given script of the given language into the given CodeBuffer.
        Parameters:
        lang - language identifier
        source - (context info) the source of this script (e.g., filename)
        lineNo - (context info) the line number in source for script
        columnNo - (context info) the column number in source for script
        script - the script to compile
        cb - code buffer to compile into
        Throws:
        BSFException - if any error while compiling the script
      • declareBean

        public void declareBean​(java.lang.String beanName,
                                java.lang.Object bean,
                                java.lang.Class type)
                         throws BSFException
        Declare a bean. The difference between declaring and registering is that engines are spsed to make declared beans "pre-available" in the scripts as far as possible. That is, if a script author needs a registered bean, he needs to look it up in some way. However if he needs a declared bean, the language has the responsibility to make those beans avaialable "automatically."

        When a bean is declared it is automatically registered as well so that any declared bean can be gotton to by looking it up as well.

        If any of the languages that are already running in this manager says they don't like this (by throwing an exception) then this method will simply quit with that exception. That is, any engines that come after than in the engine enumeration will not even be told about this new bean.

        So, in general its best to declare beans before the manager has been asked to load any engines because then the user can be informed when an engine rejects it. Also, its much more likely that an engine can declare a bean at start time than it can at any time.

        Parameters:
        beanName - name to declare bean as
        bean - the bean that's being declared
        type - the type to represent the bean as
        Throws:
        BSFException - if any of the languages that are already running decides to throw an exception when asked to declare this bean.
      • eval

        public java.lang.Object eval​(java.lang.String lang,
                                     java.lang.String source,
                                     int lineNo,
                                     int columnNo,
                                     java.lang.Object expr)
                              throws BSFException
        Evaluate the given expression of the given language and return the resulting value.
        Parameters:
        lang - language identifier
        source - (context info) the source of this expression (e.g., filename)
        lineNo - (context info) the line number in source for expr
        columnNo - (context info) the column number in source for expr
        expr - the expression to evaluate
        Throws:
        BSFException - if anything goes wrong while running the script
      • exec

        public void exec​(java.lang.String lang,
                         java.lang.String source,
                         int lineNo,
                         int columnNo,
                         java.lang.Object script)
                  throws BSFException
        Execute the given script of the given language.
        Parameters:
        lang - language identifier
        source - (context info) the source of this expression (e.g., filename)
        lineNo - (context info) the line number in source for expr
        columnNo - (context info) the column number in source for expr
        script - the script to execute
        Throws:
        BSFException - if anything goes wrong while running the script
      • iexec

        public void iexec​(java.lang.String lang,
                          java.lang.String source,
                          int lineNo,
                          int columnNo,
                          java.lang.Object script)
                   throws BSFException
        Execute the given script of the given language, attempting to emulate an interactive session w/ the language.
        Parameters:
        lang - language identifier
        source - (context info) the source of this expression (e.g., filename)
        lineNo - (context info) the line number in source for expr
        columnNo - (context info) the column number in source for expr
        script - the script to execute
        Throws:
        BSFException - if anything goes wrong while running the script
      • getClassLoader

        public java.lang.ClassLoader getClassLoader()
        Get classLoader
      • getClassPath

        public java.lang.String getClassPath()
        Get classPath
      • getLangFromFilename

        public static java.lang.String getLangFromFilename​(java.lang.String fileName)
                                                    throws BSFException
        Determine the language of a script file by looking at the file extension.
        Parameters:
        fileName - the name of the file
        Returns:
        the scripting language the file is in if the file extension is known to me (must have been registered via registerScriptingEngine).
        Throws:
        BSFException - if file's extension is unknown.
      • getObjectRegistry

        public ObjectRegistry getObjectRegistry()
        Return the current object registry of the manager.
        Returns:
        the current registry.
      • getTempDir

        public java.lang.String getTempDir()
        Get tempDir
      • isLanguageRegistered

        public static boolean isLanguageRegistered​(java.lang.String lang)
        Determine whether a language is registered.
        Parameters:
        lang - string identifying a language
        Returns:
        true iff it is
      • loadScriptingEngine

        public BSFEngine loadScriptingEngine​(java.lang.String lang)
                                      throws BSFException
        Load a scripting engine based on the lang string identifying it.
        Parameters:
        lang - string identifying language
        Throws:
        BSFException - if the language is unknown (i.e., if it has not been registered) with a reason of REASON_UNKNOWN_LANGUAGE. If the language is known but if the interface can't be created for some reason, then the reason is set to REASON_OTHER_ERROR and the actual exception is passed on as well.
      • lookupBean

        public java.lang.Object lookupBean​(java.lang.String beanName)
        return a handle to a bean registered in the bean registry by the application or a scripting engine. Returns null if bean is not found.
        Parameters:
        beanName - name of bean to look up
        Returns:
        the bean if its found or null
      • registerBean

        public void registerBean​(java.lang.String beanName,
                                 java.lang.Object bean)
        Registering a bean allows a scripting engine or the application to access that bean by name and to manipulate it.
        Parameters:
        beanName - name to register under
        bean - the bean to register
      • registerScriptingEngine

        public static void registerScriptingEngine​(java.lang.String lang,
                                                   java.lang.String engineClassName,
                                                   java.lang.String[] extensions)
        Register a scripting engine in the static registry of the BSFManager.
        Parameters:
        lang - string identifying language
        engineClassName - fully qualified name of the class interfacing the language to BSF.
        extensions - array of file extensions that should be mapped to this language type. may be null.
      • setClassLoader

        public void setClassLoader​(java.lang.ClassLoader classLoader)
        Set the class loader for those that need to use it. Default is he who loaded me or null (i.e., its Class.forName).
        Parameters:
        classLoader - the class loader to use.
      • setClassPath

        public void setClassPath​(java.lang.String classPath)
        Set the classpath for those that need to use it. Default is the value of the java.class.path property.
        Parameters:
        classPath - the classpath to use
      • setObjectRegistry

        public void setObjectRegistry​(ObjectRegistry objectRegistry)
        Set the object registry used by this manager. By default a new one is created when the manager is new'ed and this overwrites that one.
        Parameters:
        objectRegistry - the registry to use
      • setTempDir

        public void setTempDir​(java.lang.String tempDir)
        Temporary directory to put stuff into (for those who need to). Note that unless this directory is in the classpath or unless the classloader knows to look in here, any classes here will not be found! BSFManager provides a service method to load a class which uses either the classLoader provided by the class loader property or, if that fails, a class loader which knows to load from the tempdir to try to load the class. Default value of tempDir is "." (current working dir).
        Parameters:
        tempDir - the temporary directory
      • terminate

        public void terminate()
        Gracefully terminate all engines
      • undeclareBean

        public void undeclareBean​(java.lang.String beanName)
                           throws BSFException
        Undeclare a previously declared bean. This removes the bean from the list of declared beans in the manager as well as asks every running engine to undeclared the bean. As with above, if any of the engines except when asked to undeclare, this method does not catch that exception. Quietly returns if the bean is unknown.
        Parameters:
        beanName - name of bean to undeclare
        Throws:
        BSFException - if any of the languages that are already running decides to throw an exception when asked to undeclare this bean.
      • unregisterBean

        public void unregisterBean​(java.lang.String beanName)
        Unregister a previously registered bean. Silent if name is not found.
        Parameters:
        beanName - name of bean to unregister