weka.core.scripting

Class Jython

java.lang.Object

weka.core.scripting.Jython

All Implemented Interfaces:

Serializable, RevisionHandler

public class Jython
extends Object
implements Serializable, RevisionHandler

A helper class for Jython.

Version:

$Revision: 10203 $

Author:

fracpete (fracpete at waikato dot ac dot nz)

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static String	CLASS_PYTHONINERPRETER the classname of the Python interpreter
static String	CLASS_PYTHONOBJECTINPUTSTREAM the classname of the Python ObjectInputStream

Constructor Summary

Constructors

Constructor and Description
Jython() default constructor, tries to instantiate a Python Interpreter

Method Summary

Modifier and Type	Method and Description
static Object	deserialize(InputStream in) deserializes the Python Object from the stream
Object	getInterpreter() returns the currently used Python Interpreter
String	getRevision() Returns the revision string.
static Object	invoke(Object o, String methodName, Class<?>[] paramClasses, Object[] paramValues) executes the specified method and returns the result, if any
Object	invoke(String methodName, Class<?>[] paramClasses, Object[] paramValues) executes the specified method on the current interpreter and returns the result, if any.
static boolean	isPresent() returns whether the Jython classes are present or not, i.e.
static void	main(String[] args) If no arguments are given, it just prints the presence of the Jython classes, otherwise it expects a Jython filename to execute.
static Object	newInstance(File file, Class<?> template) loads the module and returns a new instance of it as instance of the provided Java class template.
static Object	newInstance(File file, Class<?> template, File[] paths) loads the module and returns a new instance of it as instance of the provided Java class template.
static Object	newInterpreter() initializes and returns a Python Interpreter

Methods inherited from class java.lang.Object

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

Field Detail

CLASS_PYTHONINERPRETER

public static final String CLASS_PYTHONINERPRETER

the classname of the Python interpreter

See Also:

Constant Field Values

CLASS_PYTHONOBJECTINPUTSTREAM

public static final String CLASS_PYTHONOBJECTINPUTSTREAM

the classname of the Python ObjectInputStream

See Also:

Constant Field Values

Constructor Detail

Jython

public Jython()

default constructor, tries to instantiate a Python Interpreter

Method Detail

getInterpreter

public Object getInterpreter()

returns the currently used Python Interpreter

Returns:

the interpreter, can be null

invoke

public Object invoke(String methodName,
                     Class<?>[] paramClasses,
                     Object[] paramValues)

executes the specified method on the current interpreter and returns the result, if any.

Parameters:

methodName - the name of the method

paramClasses - the classes of the parameters

paramValues - the values of the parameters

Returns:

the return value of the method, if any (in that case null)

isPresent

public static boolean isPresent()

returns whether the Jython classes are present or not, i.e. whether the classes are in the classpath or not

Returns:

whether the Jython classes are available

newInterpreter

public static Object newInterpreter()

initializes and returns a Python Interpreter

Returns:

the interpreter or null if Jython classes not present

newInstance

public static Object newInstance(File file,
                                 Class<?> template)

loads the module and returns a new instance of it as instance of the provided Java class template.

Parameters:

file - the Jython module file

template - the template for the returned Java object

Returns:

the Jython object

newInstance

public static Object newInstance(File file,
                                 Class<?> template,
                                 File[] paths)

loads the module and returns a new instance of it as instance of the provided Java class template. The paths are added to 'sys.path' - can be used if the module depends on other Jython modules.

Parameters:

file - the Jython module file

template - the template for the returned Java object

paths - additional paths to add to "sys.path"

Returns:

the Jython object

invoke

public static Object invoke(Object o,
                            String methodName,
                            Class<?>[] paramClasses,
                            Object[] paramValues)

executes the specified method and returns the result, if any

Parameters:

o - the object the method should be called from, e.g., a Python Interpreter

methodName - the name of the method

paramClasses - the classes of the parameters

paramValues - the values of the parameters

Returns:

the return value of the method, if any (in that case null)

deserialize

public static Object deserialize(InputStream in)

deserializes the Python Object from the stream

Parameters:

in - the stream to use

Returns:

the deserialized object

getRevision

public String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Returns:

the revision

main

public static void main(String[] args)

If no arguments are given, it just prints the presence of the Jython classes, otherwise it expects a Jython filename to execute.

Parameters:

args - commandline arguments