org.apache.bsf.engines.activescript

Class ActiveScriptEngine

java.lang.Object

org.apache.bsf.util.BSFEngineImpl

org.apache.bsf.engines.activescript.ActiveScriptEngine

All Implemented Interfaces:

java.beans.PropertyChangeListener, java.util.EventListener, BSFEngine, JavaBeanAddEventListener

public class ActiveScriptEngine
extends BSFEngineImpl
implements JavaBeanAddEventListener

This is the interface to active scripting engines from the Bean Scripting Framework. This code uses John Ponzo's IBM Active Scripting Toolkit to tie in active scripting engines to BSF. This class implements Runnable to create a thread. This thread is to exclusively access the scripting engine. All methods from this class to the engines is proxied over to the engine thread for execution. Why? Because, MS engines are implemented to only be accessed from ONE thread.

Author:

Sanjiva Weerawarana

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.String	lang

Fields inherited from class org.apache.bsf.util.BSFEngineImpl

classLoader, classPath, dbgmgr, declaredBeans, mgr, tempDir

Constructor Summary

Constructors

Constructor and Description
ActiveScriptEngine()

Method Summary

Methods

Modifier and Type	Method and Description
void	addEventListener(java.lang.Object bean, java.lang.String event, java.lang.String filter, java.lang.String script) add an event listener
int	bindMember(java.lang.Object target, java.lang.String name, short bindType) Binds a method to an integer so it can be later referenced to invoke the method via callMethod.
java.lang.Object	call(java.lang.Object object, java.lang.String method, java.lang.Object[] args) Return an object from an extension.
java.lang.Object	callMethod(java.lang.Object bean, int methodID, java.lang.Object[] args) Invokes the method assocaited with methodID on the bean with parameters in the array args.
java.lang.Object	createBean(java.lang.Object[] args) createBean
static java.lang.Throwable	createBSFException(int reason, java.lang.String msg, java.lang.Throwable t)
void	declareBean(BSFDeclaredBean bean) Declare a bean after the engine has been started.
java.lang.Object	eval(java.lang.String source, int lineNo, int columnNo, java.lang.Object oscript) This is used by an application to evaluate a string containing some expression.
void	exec(java.lang.String source, int lineNo, int columnNo, java.lang.Object script) This is used by an application to execute a string containing a script to execute.
protected void	finalize()
void	initialize(BSFManager mgr, java.lang.String language, java.util.Vector declaredBeans) initialize the engine; called right after construction by the manager.
protected boolean	isCaseSensitive()
protected boolean	isJScript()
protected boolean	isPerlScript()
protected boolean	isVBScript()
java.lang.Object	lookupBean(java.lang.String name) lookupBean
void	setEvalRet(java.lang.Object ret)
void	terminate() Graceful termination
void	undeclareBean(BSFDeclaredBean bean) Undeclare a previously declared bean.

Methods inherited from class org.apache.bsf.util.BSFEngineImpl

apply, compileApply, compileExpr, compileScript, disconnectedDebuggerNotify, getSpecificDebuggingInterface, placeBreakpointAtLine, placeBreakpointAtOffset, propertyChange, removeBreakpoint, setEntryExit

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

lang

protected java.lang.String lang

Constructor Detail

ActiveScriptEngine

public ActiveScriptEngine()

Method Detail

addEventListener

public void addEventListener(java.lang.Object bean,
                    java.lang.String event,
                    java.lang.String filter,
                    java.lang.String script)
                      throws BSFException

add an event listener

Specified by:

addEventListener in interface JavaBeanAddEventListener

Throws:

BSFException

bindMember

public final int bindMember(java.lang.Object target,
             java.lang.String name,
             short bindType)
                     throws java.lang.Exception

Binds a method to an integer so it can be later referenced to invoke the method via callMethod.

Throws:

java.lang.Exception

call

public java.lang.Object call(java.lang.Object object,
                    java.lang.String method,
                    java.lang.Object[] args)
                      throws BSFException

Return an object from an extension.

Specified by:

call in interface BSFEngine

Parameters:

method - The name of the method to call.

args - an array of arguments to be passed to the extension, which may be either Vectors of Nodes, or Strings.

object - object on which to make the call

Throws:

BSFException - if anything goes wrong while eval'ing a BSFException is thrown. The reason indicates the problem.

callMethod

public final java.lang.Object callMethod(java.lang.Object bean,
                          int methodID,
                          java.lang.Object[] args)
                                  throws java.lang.Exception

Invokes the method assocaited with methodID on the bean with parameters in the array args.

Throws:

java.lang.Exception

createBean

public final java.lang.Object createBean(java.lang.Object[] args)
                                  throws BSFException

createBean

Throws:

BSFException

createBSFException

public static final java.lang.Throwable createBSFException(int reason,
                                     java.lang.String msg,
                                     java.lang.Throwable t)

declareBean

public final void declareBean(BSFDeclaredBean bean)
                       throws BSFException

Declare a bean after the engine has been started. Declared beans are beans that are named and which the engine must make available to the scripts it runs in the most first class way possible.

Specified by:

declareBean in interface BSFEngine

Overrides:

declareBean in class BSFEngineImpl

Parameters:

bean - the bean to declare

Throws:

BSFException - if the engine cannot do this operation

eval

public java.lang.Object eval(java.lang.String source,
                    int lineNo,
                    int columnNo,
                    java.lang.Object oscript)
                      throws BSFException

This is used by an application to evaluate a string containing some expression. ActiveScript engines don't return anything .. so the return value is awlays null.

Specified by:

eval in interface BSFEngine

Parameters:

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

oscript - the expression to evaluate

Throws:

BSFException - if anything goes wrong while eval'ing a BSFException is thrown. The reason indicates the problem.

exec

public void exec(java.lang.String source,
        int lineNo,
        int columnNo,
        java.lang.Object script)
          throws BSFException

This is used by an application to execute a string containing a script to execute. ActiveScript engines don't return anything .. so the return value is awlays null.

Specified by:

exec in interface BSFEngine

Overrides:

exec in class BSFEngineImpl

Parameters:

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 exec'ing a BSFException is thrown. The reason indicates the problem.

finalize

protected void finalize()
                 throws java.lang.Throwable

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable

initialize

public void initialize(BSFManager mgr,
              java.lang.String language,
              java.util.Vector declaredBeans)
                throws BSFException

Description copied from class: BSFEngineImpl

initialize the engine; called right after construction by the manager. Declared beans are simply kept in a vector and that's it. Subclasses must do whatever they want with it.

Specified by:

initialize in interface BSFEngine

Overrides:

initialize in class BSFEngineImpl

Parameters:

mgr - The BSFManager that's hosting this engine.

language - Language string which this engine is handling.

declaredBeans - Vector of BSFDeclaredObject containing beans that should be declared into the language runtime at init time as best as possible.

Throws:

BSFException - if anything goes wrong while init'ing a BSFException is thrown. The reason indicates the problem.

isCaseSensitive

protected final boolean isCaseSensitive()

isJScript

protected final boolean isJScript()

isPerlScript

protected final boolean isPerlScript()

isVBScript

protected final boolean isVBScript()

lookupBean

public final java.lang.Object lookupBean(java.lang.String name)

lookupBean

setEvalRet

public final void setEvalRet(java.lang.Object ret)

terminate

public void terminate()

Description copied from interface: BSFEngine

Graceful termination

Specified by:

terminate in interface BSFEngine

Overrides:

terminate in class BSFEngineImpl

undeclareBean

public void undeclareBean(BSFDeclaredBean bean)
                   throws BSFException

Undeclare a previously declared bean.

Specified by:

undeclareBean in interface BSFEngine

Overrides:

undeclareBean in class BSFEngineImpl

Parameters:

bean - the bean to undeclare

Throws:

BSFException - if the engine cannot do this operation