org.clapper.util.scripting
Class UnifiedScriptEngine

java.lang.Object
  org.clapper.util.scripting.UnifiedScriptEngine

Direct Known Subclasses:

BSFScriptEngine, JavaxScriptEngine

public abstract class UnifiedScriptEngine
extends java.lang.Object

A script engine interface that provides a common set of methods that can map both the Apache Jakarta Bean Scripting Framework (BSF) and the Java 6 JSR 223 (javax.script) framework, allowing callers to use either underlying framework without changing code. This class is modeled on the JSR 223 interface, though it is much simpler.

Version:

$Revision: 6753 $

Constructor Summary

UnifiedScriptEngine()

Method Summary

UnifiedCompiledScript	compile(java.io.File scriptFile) Compile a script, if possible, returning an object that implements the UnifiedCompiledScript interface.
abstract UnifiedCompiledScript	compile(java.io.Reader scriptReader) Compile a script, if possible, returning an object that implements the UnifiedCompiledScript interface.
UnifiedCompiledScript	compile(java.lang.String scriptString) Compile a script, if possible, returning an object that implements the UnifiedCompiledScript interface.
abstract java.lang.Object	eval(java.lang.String scriptString) Evaluate a script or a script snippet and return the value of the evaluation.
void	exec(java.io.File scriptFile) Execute a script.
abstract void	exec(java.io.Reader scriptReader) Execute a script.
void	exec(java.lang.String scriptString) Execute a script.
abstract void	exec(UnifiedCompiledScript compiledScript) Execute a previously compiled script.

Methods inherited from class java.lang.Object

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

Constructor Detail

UnifiedScriptEngine

public UnifiedScriptEngine()

Method Detail

compile

public abstract UnifiedCompiledScript compile(java.io.Reader scriptReader)
                                       throws UnifiedScriptException

Compile a script, if possible, returning an object that implements the UnifiedCompiledScript interface. (The interface's name was deliberately chosen to avoid conflicts with the JSR 223 CompiledScript interface. If the underlying script engine does not support compilation, then this routine simply returns null (rather than throwing an exception).

Parameters:

scriptReader - a Reader that will produce the script

Returns:

a representation of the compiled script, or null if the underlying scripting engine does not support compilation

Throws:

UnifiedScriptException - compilation error

See Also:

compile(String), compile(File)

compile

public final UnifiedCompiledScript compile(java.lang.String scriptString)
                                    throws UnifiedScriptException

Compile a script, if possible, returning an object that implements the UnifiedCompiledScript interface. (The interface's name was deliberately chosen to avoid conflicts with the JSR 223 CompiledScript interface. If the underlying script engine does not support compilation, then this routine simply returns null (rather than throwing an exception).

Parameters:

scriptString - a String containing the script

Returns:

a representation of the compiled script, or null if the underlying scripting engine does not support compilation

Throws:

UnifiedScriptException - compilation error

See Also:

compile(File), compile(Reader)

compile

public final UnifiedCompiledScript compile(java.io.File scriptFile)
                                    throws UnifiedScriptException

Compile a script, if possible, returning an object that implements the UnifiedCompiledScript interface. (The interface's name was deliberately chosen to avoid conflicts with the JSR 223 CompiledScript interface. If the underlying script engine does not support compilation, then this routine simply returns null (rather than throwing an exception).

Parameters:

scriptFile - file containing the script; the file's extension is used to determine the language

Returns:

a representation of the compiled script, or null if the underlying scripting engine does not support compilation

Throws:

java.io.IOException - error reading script

UnifiedScriptException - compilation error

See Also:

compile(String), compile(Reader)

exec

public abstract void exec(java.io.Reader scriptReader)
                   throws UnifiedScriptException

Execute a script.

Parameters:

scriptReader - a Reader that will produce the script

Throws:

UnifiedScriptException - compilation error

See Also:

exec(String), exec(File)

exec

public final void exec(java.io.File scriptFile)
                throws UnifiedScriptException

Execute a script.

Parameters:

scriptFile - file containing the script; the file's extension is used to determine the language

Throws:

UnifiedScriptException - compilation error

See Also:

exec(String), exec(Reader)

exec

public final void exec(java.lang.String scriptString)
                throws UnifiedScriptException

Execute a script.

Parameters:

scriptString - string containing the script

Throws:

UnifiedScriptException - compilation error

See Also:

exec(File), exec(Reader)

exec

public abstract void exec(UnifiedCompiledScript compiledScript)
                   throws UnifiedScriptException

Execute a previously compiled script.

Parameters:

compiledScript - the compiled script

Throws:

UnifiedScriptException - compilation error

See Also:

exec(File), exec(Reader)

eval

public abstract java.lang.Object eval(java.lang.String scriptString)
                               throws UnifiedScriptException

Evaluate a script or a script snippet and return the value of the evaluation.

Parameters:

scriptString - the script string

Returns:

the result of the evaluation, if anything

Throws:

UnifiedScriptException - on error