ElementModel (OPS4J Pax Web - Service SPI (internal) 8.0.27 API)

java.lang.Object
- org.ops4j.pax.web.service.spi.model.Identity
- - org.ops4j.pax.web.service.spi.model.elements.ElementModel<T,D>

Type Parameters:

T - type of the service that user registers to be processed by Whiteboard extender (whether standard OSGi CMPN Whiteboard or Pax Web specific Whiteboard extender)

D - type of the DTO-like object that carries registration information of real service - to be able to get notified about (un)registration without the way to change actual registration data

All Implemented Interfaces:

Comparable<ElementModel<T,D>>

Direct Known Subclasses:

ContainerInitializerModel, ErrorPageModel, EventListenerModel, FilterModel, JspModel, SecurityConfigurationModel, ServletModel, WebSocketModel, WelcomeFileModel
```
public abstract class ElementModel<T,D extends WebElementEventData>
extends Identity
implements Comparable<ElementModel<T,D>>
```
Base class for all models representing actual elements of a web application (or context), the most obvious model is representing Servlet.

What user does (through HttpService or by publishing Whiteboard services) is a registration of web elements (like servlets) always within the context of ... well, a context (possibly many, as permitted by Whiteboard Service specification).

A context is not an element itself (thus - not a model), it's rather:
- actual ServletContext from server point of view
- OSGi abstraction (HttpContext or ServletContextHelper) providing additional/bridged functionality, when delegating some of it to actual ServletContext
Each element, when registered through Whiteboard Service, may turn out to unregister some existing element when it uses conflicting URL mapping but has lower ranking or service id. Such conflicts lead to trivial NamespaceException when using Http Service.

Field Summary

Fields
Modifier and Type	Field and Description
`protected List<OsgiContextModel>`	`contextModels` List of `osgi contexts` with which given `ElementModel` is associated.
`protected String`	`contextModelsInfo`
`protected int`	`dtoFailureCode` If there's any failure during the lifetime of the context, we can provide a failure DTO information here.
`protected Boolean`	`isValid`

Constructor Summary

Constructors
Constructor and Description

ElementModel()

Constructors
Constructor and Description
`ElementModel()`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addContextModel(OsgiContextModel model)` This method is used to add `OsgiContextModel` when an `ElementModel` is created for the first time (whether it's Whiteboard or HttpService scenario).
`abstract D`	`asEventData()` When sending events related to `ElementModel` we can't use the same instance which is kept in `ServerModel`, we have to copy relevant information to lightweight object.
`void`	`changeContextModels(List<OsgiContextModel> models)` This method replaces the models for existing when conditions change (when for example new `OsgiContextModel` is registered and element should be registered to it after it was already registered to other context matching the context selector).
`int`	`compareTo(ElementModel<T,D> o)` Returns negative value if this element is "lesser" than the argument, which means it should have higher priority.
`boolean`	`equals(Object o)`
`org.osgi.framework.Filter`	`getContextFilter()`
`List<OsgiContextModel>`	`getContextModels()` Get unmodifiable list of `osgi models` with which given `ElementModel` should be associated during registration.
`String`	`getContextModelsInfo()`
`String`	`getContextSelector()`
`int`	`getDtoFailureCode()`
`org.osgi.framework.ServiceReference<T>`	`getElementReference()`
`Supplier<? extends T>`	`getElementSupplier()`
`org.osgi.framework.Bundle`	`getRegisteringBundle()`
`long`	`getServiceId()`
`int`	`getServiceRank()`
`long`	`getTimestamp()`
`boolean`	`hasContextModels()`
`int`	`hashCode()`
`boolean`	`isAsynchronusRegistration()`
`boolean`	`isPrototype()` Should be used only when `getElementReference()` returns non-null value.
`boolean`	`isValid()` This method should be called from Whiteboard infrastructure to really perform the validation and set isValid flag, which is then used for "Failure DTO" purposes.
`abstract Boolean`	`performValidation()` Perform element-specific validation and throws different exceptions for all element-specific validation problems.
`abstract void`	`register(WhiteboardWebContainerView view)` Each `ElementModel` can register itself as Whiteboard element.
`void`	`resetContextModels()` Method used when Whiteboard service changes its registration properties
`void`	`setAsynchronusRegistration(boolean async)`
`protected void`	`setCommonEventProperties(WebElementEventData data)` Set `ElementModel` information in `WebElementEventData` - to be called in specializations of `asEventData()` method.
`void`	`setContextSelectFilter(org.osgi.framework.Filter contextFilter)` Method corresponding to `ContextRelated.getContextSelectFilter()` that sets actual context-selection `Filter` to be used for this `ElementModel` after customizing incoming user-registered OSGi service.
`void`	`setContextSelector(String mappingSelector)` Some Whiteboard services specify context selector using `HttpWhiteboardConstants.HTTP_WHITEBOARD_CONTEXT_SELECT` service registration property and some (legacy) using `ContextRelated.getContextId()`/`ContextRelated.getContextSelectFilter()`.
`void`	`setDtoFailureCode(int dtoFailureCode)`
`void`	`setElementReference(org.osgi.framework.ServiceReference<T> elementReference)`
`void`	`setElementSupplier(Supplier<? extends T> elementSupplier)`
`void`	`setRegisteringBundle(org.osgi.framework.Bundle registeringBundle)`
`void`	`setServiceId(long serviceId)`
`void`	`setServiceRank(int serviceRank)`
`void`	`setTimestamp(long timestamp)`
`String`	`toString()`
`abstract void`	`unregister(WhiteboardWebContainerView view)` Each `ElementModel` can unregister itself as Whiteboard element.

Methods inherited from class org.ops4j.pax.web.service.spi.model.Identity
getId, getIdPrefix, getNumericId

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - contextModels
```
protected List<OsgiContextModel> contextModels
```
    List of osgi contexts with which given ElementModel is associated. This list may be altered using addContextModel(OsgiContextModel), but on first invocation of getContextModels(), this list is latched, sorted and can't be modified any further.
  - contextModelsInfo
```
protected String contextModelsInfo
```
  - isValid
```
protected Boolean isValid
```
  - dtoFailureCode
```
protected int dtoFailureCode
```
    If there's any failure during the lifetime of the context, we can provide a failure DTO information here.
- Constructor Detail
  - ElementModel
```
public ElementModel()
```
- Method Detail
  - isValid
```
public boolean isValid()
```
    This method should be called from Whiteboard infrastructure to really perform the validation and set isValid flag, which is then used for "Failure DTO" purposes.
  - performValidation
```
public abstract Boolean performValidation()
                                   throws Exception
```
    Perform element-specific validation and throws different exceptions for all element-specific validation problems. This method should not be called for Whiteboard purposes, where "failure DTO" has to be configured.
    
    This method should be called in Http Service scenario where we immediately need strong feedback - with exceptions thrown for all validation problems. In Whiteboard scenario, the exception is caught, logged and it's the tracker that prevents further registration.
    
    This method may alter the state of the model when (which is possible during validation) some extra information is obtained/compiled/processed.
    
    Returns:
    
    Throws:
    
    Exception
  - getContextModels
```
public List<OsgiContextModel> getContextModels()
```
    Get unmodifiable list of osgi models with which given ElementModel should be associated during registration.
    
    Returns:
  - getContextModelsInfo
```
public String getContextModelsInfo()
```
  - addContextModel
```
public void addContextModel(OsgiContextModel model)
```
    This method is used to add OsgiContextModel when an ElementModel is created for the first time (whether it's Whiteboard or HttpService scenario).
    
    Parameters:
    
    model -
  - changeContextModels
```
public void changeContextModels(List<OsgiContextModel> models)
```
    This method replaces the models for existing when conditions change (when for example new OsgiContextModel is registered and element should be registered to it after it was already registered to other context matching the context selector).
  - resetContextModels
```
public void resetContextModels()
```
    Method used when Whiteboard service changes its registration properties
  - register
```
public abstract void register(WhiteboardWebContainerView view)
```
    Each ElementModel can register itself as Whiteboard element.
    
    Parameters:
    
    view -
  - unregister
```
public abstract void unregister(WhiteboardWebContainerView view)
```
    Each ElementModel can unregister itself as Whiteboard element.
    
    Parameters:
    
    view -
  - asEventData
```
public abstract D asEventData()
```
    When sending events related to ElementModel we can't use the same instance which is kept in ServerModel, we have to copy relevant information to lightweight object.
    
    Returns:
  - setCommonEventProperties
```
protected void setCommonEventProperties(WebElementEventData data)
```
    Set ElementModel information in WebElementEventData - to be called in specializations of asEventData() method.
    
    Parameters:
    
    data -
  - hasContextModels
```
public boolean hasContextModels()
```
  - getServiceRank
```
public int getServiceRank()
```
  - setServiceRank
```
public void setServiceRank(int serviceRank)
```
  - getServiceId
```
public long getServiceId()
```
  - setServiceId
```
public void setServiceId(long serviceId)
```
  - getTimestamp
```
public long getTimestamp()
```
  - setTimestamp
```
public void setTimestamp(long timestamp)
```
  - getElementReference
```
public org.osgi.framework.ServiceReference<T> getElementReference()
```
  - setElementReference
```
public void setElementReference(org.osgi.framework.ServiceReference<T> elementReference)
```
  - isPrototype
```
public boolean isPrototype()
```
    Should be used only when getElementReference() returns non-null value.
    
    Returns:
  - getElementSupplier
```
public Supplier<? extends T> getElementSupplier()
```
  - setElementSupplier
```
public void setElementSupplier(Supplier<? extends T> elementSupplier)
```
  - getRegisteringBundle
```
public org.osgi.framework.Bundle getRegisteringBundle()
```
  - setRegisteringBundle
```
public void setRegisteringBundle(org.osgi.framework.Bundle registeringBundle)
```
  - setContextSelector
```
public void setContextSelector(String mappingSelector)
```
    Some Whiteboard services specify context selector using HttpWhiteboardConstants.HTTP_WHITEBOARD_CONTEXT_SELECT service registration property and some (legacy) using ContextRelated.getContextId()/ContextRelated.getContextSelectFilter(). After setting the selector, we no longer have to resolve one.
    
    Parameters:
    
    mappingSelector -
  - getContextSelector
```
public String getContextSelector()
```
  - setContextSelectFilter
```
public void setContextSelectFilter(org.osgi.framework.Filter contextFilter)
```
    Method corresponding to ContextRelated.getContextSelectFilter() that sets actual context-selection Filter to be used for this ElementModel after customizing incoming user-registered OSGi service.
    
    This filter can be changed only by calling ServiceRegistration.setProperties(Dictionary) on existing registration, but it's rather rare scenario. The point is that this filter is called every time new OsgiContextModel is tracked (or changed or removed) to check whether existing set of contexts associated with given ElementModel has changed - to check whether this ElementModel should be added to new or removed from existing contexts (or both)
    
    Parameters:
    
    contextFilter -
  - getContextFilter
```
public org.osgi.framework.Filter getContextFilter()
```
  - getDtoFailureCode
```
public int getDtoFailureCode()
```
  - setDtoFailureCode
```
public void setDtoFailureCode(int dtoFailureCode)
```
  - setAsynchronusRegistration
```
public void setAsynchronusRegistration(boolean async)
```
  - isAsynchronusRegistration
```
public boolean isAsynchronusRegistration()
```
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Identity
  - compareTo
```
public int compareTo(ElementModel<T,D> o)
```
    Returns negative value if this element is "lesser" than the argument, which means it should have higher priority.
    
    Specified by:
    
    compareTo in interface Comparable<ElementModel<T,D extends WebElementEventData>>
    
    Parameters:
    
    o -
    
    Returns:
  - equals
```
public final boolean equals(Object o)
```
    Overrides:
    
    equals in class Identity
  - hashCode
```
public final int hashCode()
```
    Overrides:
    
    hashCode in class Identity

Class ElementModel<T,D extends WebElementEventData>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class org.ops4j.pax.web.service.spi.model.Identity

Methods inherited from class java.lang.Object

Field Detail

contextModels

contextModelsInfo

isValid

dtoFailureCode

Constructor Detail

ElementModel

Method Detail

isValid

performValidation

getContextModels

getContextModelsInfo

addContextModel

changeContextModels

resetContextModels

register

unregister

asEventData

setCommonEventProperties

hasContextModels

getServiceRank

setServiceRank

getServiceId

setServiceId

getTimestamp

setTimestamp

getElementReference

setElementReference

isPrototype

getElementSupplier

setElementSupplier

getRegisteringBundle

setRegisteringBundle

setContextSelector

getContextSelector

setContextSelectFilter

getContextFilter

getDtoFailureCode

setDtoFailureCode

setAsynchronusRegistration

isAsynchronusRegistration

toString

compareTo

equals

hashCode