org.openmrs.util

Class HandlerUtil

java.lang.Object

org.openmrs.util.HandlerUtil

All Implemented Interfaces:

java.util.EventListener, org.springframework.context.ApplicationListener<org.springframework.context.event.ContextRefreshedEvent>

@Component
public class HandlerUtil
extends java.lang.Object
implements org.springframework.context.ApplicationListener<org.springframework.context.event.ContextRefreshedEvent>

Utility class that provides useful methods for working with classes that are annotated with the Handler annotation

Since:

1.5

Constructor Summary

Constructors

Constructor and Description
HandlerUtil()

Method Summary

Modifier and Type	Method and Description
static void	clearCachedHandlers()
static <H,T> java.util.List<H>	getHandlersForType(java.lang.Class<H> handlerType, java.lang.Class<T> type) Retrieves a List of all registered components from the Context that are of the passed handlerType and one or more of the following is true: The handlerType is annotated as a Handler that supports the passed type The passed type is null - this effectively returns all components of the passed handlerType The returned handlers are ordered in the list based upon the order property.
static java.lang.Integer	getOrderOfHandler(java.lang.Class<?> handlerClass) Utility method to return the order attribute of the Handler annotation on the passed class.
static <H,T> H	getPreferredHandler(java.lang.Class<H> handlerType, java.lang.Class<T> type) Retrieves the preferred Handler for a given handlerType and type.
void	onApplicationEvent(org.springframework.context.event.ContextRefreshedEvent event)

Methods inherited from class java.lang.Object

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

Constructor Detail

HandlerUtil

public HandlerUtil()

Method Detail

clearCachedHandlers

public static void clearCachedHandlers()

getHandlersForType

public static <H,T> java.util.List<H> getHandlersForType(java.lang.Class<H> handlerType,
                                                         java.lang.Class<T> type)

Retrieves a List of all registered components from the Context that are of the passed handlerType and one or more of the following is true:

• The handlerType is annotated as a Handler that supports the passed type
• The passed type is null - this effectively returns all components of the passed handlerType

The returned handlers are ordered in the list based upon the order property.

Parameters:

handlerType - Indicates the type of class to return

type - Indicates the type that the given handlerType must support (or null for any)

Returns:

a List of all matching Handlers for the given parameters, ordered by Handler#order

getPreferredHandler

public static <H,T> H getPreferredHandler(java.lang.Class<H> handlerType,
                                          java.lang.Class<T> type)

Retrieves the preferred Handler for a given handlerType and type. A preferred handler is the Handler that has the lowest defined order attribute in it's annotation. If multiple Handlers are found for the passed parameters at the lowest specified order, then an APIException is thrown.

Parameters:

handlerType - the class that is an annotated Handler to retrieve

type - the class that the annotated Handler must support

Returns:

the class of the passed hanlerType with the lowest configured order

getOrderOfHandler

public static java.lang.Integer getOrderOfHandler(java.lang.Class<?> handlerClass)

Utility method to return the order attribute of the Handler annotation on the passed class. If the passed class does not have a Handler annotation, a RuntimeException is thrown

Parameters:

handlerClass -

Returns:

the order attribute value

onApplicationEvent

public void onApplicationEvent(org.springframework.context.event.ContextRefreshedEvent event)

Specified by:

onApplicationEvent in interface org.springframework.context.ApplicationListener<org.springframework.context.event.ContextRefreshedEvent>