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org.apache.oozie.service
Class ELService

java.lang.Object
  org.apache.oozie.service.ELService

All Implemented Interfaces:

Service

public class ELService
extends Object
implements Service

The ELService creates ELEvaluator instances preconfigured with constants and functions defined in the configuration.

The following configuration parameters control the EL service:

CONF_CONSTANTS list of constant definitions to be available for EL evaluations.

CONF_FUNCTIONS list of function definitions to be available for EL evalations.

Definitions must be separated by a comma, definitions are trimmed.

The syntax for a constant definition is PREFIX:NAME=CLASS_NAME#CONSTANT_NAME.

The syntax for a constant definition is PREFIX:NAME=CLASS_NAME#METHOD_NAME.

Field Summary

static String	CONF_CONSTANTS
static String	CONF_EXT_CONSTANTS
static String	CONF_EXT_FUNCTIONS
static String	CONF_FUNCTIONS
static String	CONF_GROUPS
static String	CONF_PREFIX

Fields inherited from interface org.apache.oozie.service.Service

DEFAULT_LOCK_TIMEOUT, lockTimeout, USE_XCOMMAND

Constructor Summary

ELService()

Method Summary

ELEvaluator	createEvaluator(String group) Return an ELEvaluator pre-configured with the constants and functions for the specific group of EL-functions and variables defined in the configuration.
void	destroy() Destroy the EL service.
static Object	findConstant(String className, String constantName)
static Method	findMethod(String className, String methodName)
Class<? extends Service>	getInterface() Return the public interface for EL service.
void	init(Services services) Initialize the EL service.

Methods inherited from class java.lang.Object

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

Field Detail

CONF_PREFIX

public static final String CONF_PREFIX

See Also:

Constant Field Values

CONF_CONSTANTS

public static final String CONF_CONSTANTS

See Also:

Constant Field Values

CONF_EXT_CONSTANTS

public static final String CONF_EXT_CONSTANTS

See Also:

Constant Field Values

CONF_FUNCTIONS

public static final String CONF_FUNCTIONS

See Also:

Constant Field Values

CONF_EXT_FUNCTIONS

public static final String CONF_EXT_FUNCTIONS

See Also:

Constant Field Values

CONF_GROUPS

public static final String CONF_GROUPS

See Also:

Constant Field Values

Constructor Detail

ELService

public ELService()

Method Detail

init

public void init(Services services)
          throws ServiceException

Initialize the EL service.

Specified by:

init in interface Service

Parameters:

services - services instance.

Throws:

ServiceException - thrown if the EL service could not be initialized.

destroy

public void destroy()

Destroy the EL service.

Specified by:

destroy in interface Service

getInterface

public Class<? extends Service> getInterface()

Return the public interface for EL service.

Specified by:

getInterface in interface Service

Returns:

ELService.

createEvaluator

public ELEvaluator createEvaluator(String group)

Return an ELEvaluator pre-configured with the constants and functions for the specific group of EL-functions and variables defined in the configuration. If the group name doesn't exist, IllegalArgumentException is thrown

Parameters:

group: - Name of the group of required EL Evaluator.

Returns:

a preconfigured ELEvaluator.

findMethod

public static Method findMethod(String className,
                                String methodName)
                         throws ServiceException

Throws:

ServiceException

findConstant

public static Object findConstant(String className,
                                  String constantName)
                           throws ServiceException

Throws:

ServiceException