org.springframework.data.hadoop.pig

Class PigTemplate

java.lang.Object

org.springframework.data.hadoop.pig.PigTemplate

All Implemented Interfaces:

org.springframework.beans.factory.Aware, org.springframework.beans.factory.InitializingBean, org.springframework.context.ResourceLoaderAware, PigOperations

public class PigTemplate
extends java.lang.Object
implements org.springframework.beans.factory.InitializingBean, PigOperations, org.springframework.context.ResourceLoaderAware

Helper class that simplifies Pig data access code. Automatically handles the creation of a PigServer (which is non-thread-safe) and converts Pig exceptions into DataAccessExceptions.

Author:

Costin Leau

Constructor Summary

Constructors

Constructor and Description
PigTemplate() Constructs a new PigTemplate instance.
PigTemplate(PigServerFactory pigFactory) Constructs a new PigTemplate instance.

Method Summary

Methods

Modifier and Type	Method and Description
void	afterPropertiesSet()
protected org.springframework.dao.DataAccessException	convertPigAccessException(org.apache.pig.backend.executionengine.ExecException ex) Converts the given Pig exception to an appropriate exception from the org.springframework.dao hierarchy.
protected org.springframework.dao.DataAccessException	convertPigAccessException(java.io.IOException ex) Converts the given Pig exception to an appropriate exception from the org.springframework.dao hierarchy.
protected org.apache.pig.PigServer	createPigServer()
<T> T	execute(PigCallback<T> action) Executes the action specified by the given callback object within an active PigServer.
java.util.List<org.apache.pig.backend.executionengine.ExecJob>	executeScript(java.lang.Iterable<PigScript> scripts) Executes multiple scripts that result in a list of job executions.
java.util.List<org.apache.pig.backend.executionengine.ExecJob>	executeScript(PigScript script) Executes the given script identified by location and arguments that results in a list of job executions.
java.util.List<org.apache.pig.backend.executionengine.ExecJob>	executeScript(java.lang.String script) Executes the given Pig Latin that results in a list of job executions.
java.util.List<org.apache.pig.backend.executionengine.ExecJob>	executeScript(java.lang.String script, java.util.Map<?,?> arguments) Executes the given Pig Latin with arguments that results in a list of job executions.
void	setPigFactory(PigServerFactory pigServerFactory) Sets the PigServer factory.
void	setResourceLoader(org.springframework.core.io.ResourceLoader resourceLoader)

Methods inherited from class java.lang.Object

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

Constructor Detail

PigTemplate

public PigTemplate()

Constructs a new PigTemplate instance. Expects setPigFactory(PigServerFactory) to be called before using it.

PigTemplate

public PigTemplate(PigServerFactory pigFactory)

Constructs a new PigTemplate instance.

Parameters:

pigFactory - pig factory

Method Detail

afterPropertiesSet

public void afterPropertiesSet()

Specified by:

afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean

execute

public <T> T execute(PigCallback<T> action)
          throws org.springframework.dao.DataAccessException

Executes the action specified by the given callback object within an active PigServer.

Specified by:

execute in interface PigOperations

Type Parameters:

T - action type

Parameters:

action - callback object that specifies the Hive action

Returns:

the action result object

Throws:

org.springframework.dao.DataAccessException - exception

convertPigAccessException

protected org.springframework.dao.DataAccessException convertPigAccessException(java.io.IOException ex)

Converts the given Pig exception to an appropriate exception from the org.springframework.dao hierarchy.

Parameters:

ex - Pig exception

Returns:

a corresponding DataAccessException

convertPigAccessException

protected org.springframework.dao.DataAccessException convertPigAccessException(org.apache.pig.backend.executionengine.ExecException ex)

Converts the given Pig exception to an appropriate exception from the org.springframework.dao hierarchy.

Parameters:

ex - Pig exception

Returns:

a corresponding DataAccessException

executeScript

public java.util.List<org.apache.pig.backend.executionengine.ExecJob> executeScript(java.lang.String script)
                                                                             throws org.springframework.dao.DataAccessException

Executes the given Pig Latin that results in a list of job executions. The script is interpreted as a URL or if that fails, as a Pig Latin statement.

Specified by:

executeScript in interface PigOperations

Parameters:

script - script URL or pig latin statement

Returns:

list of job executions

Throws:

org.springframework.dao.DataAccessException - exception

executeScript

public java.util.List<org.apache.pig.backend.executionengine.ExecJob> executeScript(java.lang.String script,
                                                                           java.util.Map<?,?> arguments)
                                                                             throws org.springframework.dao.DataAccessException

Executes the given Pig Latin with arguments that results in a list of job executions. The script is interpreted as a URL or if that fails, as a Pig Latin statement.

Specified by:

executeScript in interface PigOperations

Parameters:

script - script URL or pig latin statement

arguments - script arguments

Returns:

list of job executions

Throws:

org.springframework.dao.DataAccessException - exception

executeScript

public java.util.List<org.apache.pig.backend.executionengine.ExecJob> executeScript(PigScript script)
                                                                             throws org.springframework.dao.DataAccessException

Executes the given script identified by location and arguments that results in a list of job executions.

Specified by:

executeScript in interface PigOperations

Parameters:

script - script location and arguments

Returns:

list of job executions

Throws:

org.springframework.dao.DataAccessException - exception

executeScript

public java.util.List<org.apache.pig.backend.executionengine.ExecJob> executeScript(java.lang.Iterable<PigScript> scripts)
                                                                             throws org.springframework.dao.DataAccessException

Executes multiple scripts that result in a list of job executions.

Specified by:

executeScript in interface PigOperations

Parameters:

scripts - scripts location and arguments

Returns:

list of job executions

Throws:

org.springframework.dao.DataAccessException - exception

createPigServer

protected org.apache.pig.PigServer createPigServer()

setPigFactory

public void setPigFactory(PigServerFactory pigServerFactory)

Sets the PigServer factory.

Parameters:

pigServerFactory - pig server factory

setResourceLoader

public void setResourceLoader(org.springframework.core.io.ResourceLoader resourceLoader)

Specified by:

setResourceLoader in interface org.springframework.context.ResourceLoaderAware