org.apache.pig.scripting.jython
Class JythonScriptEngine

java.lang.Object
  org.apache.pig.scripting.ScriptEngine
      org.apache.pig.scripting.jython.JythonScriptEngine

public class JythonScriptEngine
extends ScriptEngine

Implementation of the script engine for Jython

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.pig.scripting.ScriptEngine

ScriptEngine.SupportedScriptLang

Field Summary

Fields inherited from class org.apache.pig.scripting.ScriptEngine

NAMESPACE_SEPARATOR

Constructor Summary

JythonScriptEngine()

Method Summary

static org.python.core.PyFunction	getFunction(String path, String functionName) Gets the Python function object.
protected Map<String,Object>	getParamsFromVariables() Returns a map from local variable names to their values
protected String	getScriptingLang() Gets ScriptEngine classname or keyword for the scripting language
void	load(InputStream script, String scriptFile, PigContext pigContext) execs the script text using the interpreter.
protected Map<String,List<PigStats>>	main(PigContext pigContext, String scriptFile) Actually runs the script file.
void	registerFunctions(String path, String namespace, PigContext pigContext) Registers scripting language functions as Pig functions with given namespace

Methods inherited from class org.apache.pig.scripting.ScriptEngine

getInstance, getJarPath, getPigStatsMap, getScriptAsStream, getSupportedScriptLang, run

Methods inherited from class java.lang.Object

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

Constructor Detail

JythonScriptEngine

public JythonScriptEngine()

Method Detail

registerFunctions

public void registerFunctions(String path,
                              String namespace,
                              PigContext pigContext)
                       throws IOException

Description copied from class: ScriptEngine

Registers scripting language functions as Pig functions with given namespace

Specified by:

registerFunctions in class ScriptEngine

Parameters:

path - path of the script

namespace - namespace for the functions

pigContext - pigcontext to register functions to pig in the given namespace

Throws:

IOException

getFunction

public static org.python.core.PyFunction getFunction(String path,
                                                     String functionName)
                                              throws IOException

Gets the Python function object.

Parameters:

path - Path of the jython script file containing the function.

functionName - Name of the function

Returns:

a function object

Throws:

IOException

main

protected Map<String,List<PigStats>> main(PigContext pigContext,
                                          String scriptFile)
                                   throws IOException

Description copied from class: ScriptEngine

Actually runs the script file. This method will be implemented by individual script engines.

Specified by:

main in class ScriptEngine

Parameters:

pigContext - ScriptPigContext to run the script file

scriptFile - the file

Throws:

IOException

load

public void load(InputStream script,
                 String scriptFile,
                 PigContext pigContext)
          throws IOException

execs the script text using the interpreter. populates the pig context with necessary module paths. does not close the inputstream.

Parameters:

script -

scriptFile -

pigContext -

Throws:

IOException

getScriptingLang

protected String getScriptingLang()

Description copied from class: ScriptEngine

Gets ScriptEngine classname or keyword for the scripting language

Specified by:

getScriptingLang in class ScriptEngine

getParamsFromVariables

protected Map<String,Object> getParamsFromVariables()
                                             throws IOException

Description copied from class: ScriptEngine

Returns a map from local variable names to their values

Specified by:

getParamsFromVariables in class ScriptEngine

Throws:

IOException