UIComponentBase (Java EE 5 SDK)

javax.faces.component Class UIComponentBase

java.lang.Object
  javax.faces.component.UIComponent
      javax.faces.component.UIComponentBase

所有已实现的接口:

StateHolder

直接已知子类:

UIColumn, UICommand, UIData, UIForm, UIGraphic, UIMessage, UIMessages, UINamingContainer, UIOutput, UIPanel, UIParameter, UISelectItem, UISelectItems, UIViewRoot

public abstract class UIComponentBase

extends UIComponent

UIComponentBase is a convenience base class that implements the default concrete behavior of all methods defined by UIComponent.

By default, this class defines getRendersChildren() to find the renderer for this component and call its getRendersChildren() method. The default implementation on the Renderer returns false. As of version 1.2 of the JavaServer Faces Specification, component authors are encouraged to return true from this method and rely on the implementation of encodeChildren(javax.faces.context.FacesContext) in this class and in the Renderer (Renderer.encodeChildren(javax.faces.context.FacesContext, javax.faces.component.UIComponent)). Subclasses that wish to manage the rendering of their children should override this method to return true instead.

UIComponentBase

public UIComponentBase()

getAttributes

public Map<String,Object> getAttributes()

Description copied from class: UIComponent

Return a mutable Map representing the attributes (and properties, see below) associated wth this UIComponent, keyed by attribute name (which must be a String). The returned implementation must support all of the standard and optional Map methods, plus support the following additional requirements:

• The Map implementation must implement the java.io.Serializable interface.
• Any attempt to add a null key or value must throw a NullPointerException.
• Any attempt to add a key that is not a String must throw a ClassCastException.
• If the attribute name specified as a key matches a property of this UIComponent's implementation class, the following methods will have special behavior:
  • containsKey - Return false.
  • get() - If the property is readable, call the getter method and return the returned value (wrapping primitive values in their corresponding wrapper classes); otherwise throw IllegalArgumentException.
  • put() - If the property is writeable, call the setter method to set the corresponding value (unwrapping primitive values in their corresponding wrapper classes). If the property is not writeable, or an attempt is made to set a property of primitive type to null, throw IllegalArgumentException.
  • remove - Throw IllegalArgumentException.

规范说明:

getAttributes in class UIComponent

getValueBinding

public ValueBinding getValueBinding(String name)

Deprecated. This has been replaced by UIComponent.getValueExpression(java.lang.String).

Call through to UIComponent.getValueExpression(java.lang.String) and examine the result. If the result is an instance of the wrapper class mandated in UIComponent.setValueBinding(java.lang.String, javax.faces.el.ValueBinding), extract the ValueBinding instance and return it. Otherwise, wrap the result in an implementation of ValueBinding, and return it.

规范说明:

getValueBinding in class UIComponent

参数:

name - Name of the attribute or property for which to retrieve a ValueBinding

抛出异常:

NullPointerException - if name is null

setValueBinding

public void setValueBinding(String name,
                            ValueBinding binding)

Deprecated. This has been replaced by UIComponent.setValueExpression(java.lang.String, javax.el.ValueExpression).

Wrap the argument binding in an implementation of ValueExpression and call through to UIComponent.setValueExpression(java.lang.String, javax.el.ValueExpression).

规范说明:

setValueBinding in class UIComponent

参数:

name - Name of the attribute or property for which to set a ValueBinding

binding - The ValueBinding to set, or null to remove any currently set ValueBinding

抛出异常:

IllegalArgumentException - if name is one of id or parent

NullPointerException - if name is null

getClientId

public String getClientId(FacesContext context)

Description copied from class: UIComponent

Return a client-side identifier for this component, generating one if necessary. The associated Renderer, if any, will be asked to convert the clientId to a form suitable for transmission to the client.

The return from this method must be the same value throughout the lifetime of the instance, unless the id property of the component is changed, or the component is placed in a NamingContainer whose client ID changes (for example, UIData). However, even in these cases, consecutive calls to this method must always return the same value. The implementation must follow these steps in determining the clientId:

Find the closest ancestor to this component in the view hierarchy that implements NamingContainer. Call getContainerClientId() on it and save the result as the parentId local variable. Call UIComponent.getId() on this component and save the result as the myId local variable. If myId is null, call context.getViewRoot().createUniqueId() and assign the result to myId. If parentId is non-null, let myId equal parentId + NamingContainer.SEPARATOR_CHAR + myId. Call Renderer.convertClientId(javax.faces.context.FacesContext, java.lang.String), passing myId, and return the result.

规范说明:

getClientId in class UIComponent

参数:

context - The FacesContext for the current request

抛出异常:

NullPointerException - if context is null

getId

public String getId()

Description copied from class: UIComponent

Return the component identifier of this UIComponent.

规范说明:

getId in class UIComponent

setId

public void setId(String id)

Description copied from class: UIComponent

Set the component identifier of this UIComponent (if any). Component identifiers must obey the following syntax restrictions:

• Must not be a zero-length String.
• First character must be a letter or an underscore ('_').
• Subsequent characters must be a letter, a digit, an underscore ('_'), or a dash ('-').

Component identifiers must also obey the following semantic restrictions (note that this restriction is NOT enforced by the setId() implementation):

• The specified identifier must be unique among all the components (including facets) that are descendents of the nearest ancestor UIComponent that is a NamingContainer, or within the scope of the entire component tree if there is no such ancestor that is a NamingContainer.

规范说明:

setId in class UIComponent

参数:

id - The new component identifier, or null to indicate that this UIComponent does not have a component identifier

抛出异常:

IllegalArgumentException - if id is not syntactically valid

IllegalStateException

getParent

public UIComponent getParent()

Description copied from class: UIComponent

Return the parent UIComponent of this UIComponent, if any. A component must allow child components to be added to and removed from the list of children of this component, even though the child component returns null from getParent( ).

规范说明:

getParent in class UIComponent

setParent

public void setParent(UIComponent parent)

Description copied from class: UIComponent

Set the parent UIComponent of this UIComponent. This method must never be called by developers; a UIComponent's internal implementation will call it as components are added to or removed from a parent's child List or facet Map.

规范说明:

setParent in class UIComponent

参数:

parent - The new parent, or null for the root node of a component tree

isRendered

public boolean isRendered()

Description copied from class: UIComponent

Return true if this component (and its children) should be rendered during the Render Response phase of the request processing lifecycle.

规范说明:

isRendered in class UIComponent

setRendered

public void setRendered(boolean rendered)

Description copied from class: UIComponent

Set the rendered property of this UIComponent.

规范说明:

setRendered in class UIComponent

参数:

rendered - If true render this component; otherwise, do not render this component

getRendererType

public String getRendererType()

Description copied from class: UIComponent

Return the Renderer type for this UIComponent (if any).

规范说明:

getRendererType in class UIComponent

setRendererType

public void setRendererType(String rendererType)

Description copied from class: UIComponent

Set the Renderer type for this UIComponent, or null for components that render themselves.

规范说明:

setRendererType in class UIComponent

参数:

rendererType - Logical identifier of the type of Renderer to use, or null for components that render themselves

getRendersChildren

public boolean getRendersChildren()

Description copied from class: UIComponent

Return a flag indicating whether this component is responsible for rendering its child components. The default implementation in getRendersChildren() tries to find the renderer for this component. If it does, it calls Renderer.getRendersChildren() and returns the result. If it doesn't, it returns false. As of version 1.2 of the JavaServer Faces Specification, component authors are encouraged to return true from this method and rely on encodeChildren(javax.faces.context.FacesContext).

规范说明:

getRendersChildren in class UIComponent

getChildren

public List<UIComponent> getChildren()

Description copied from class: UIComponent

Return a mutable List representing the child UIComponents associated with this component. The returned implementation must support all of the standard and optional List methods, plus support the following additional requirements:

• The List implementation must implement the java.io.Serializable interface.
• Any attempt to add a null must throw a NullPointerException
• Any attempt to add an object that does not implement UIComponent must throw a ClassCastException.
• Whenever a new child component is added, the parent property of the child must be set to this component instance. If the parent property of the child was already non-null, the child must first be removed from its previous parent (where it may have been either a child or a facet).
• Whenever an existing child component is removed, the parent property of the child must be set to null.

规范说明:

getChildren in class UIComponent

getChildCount

public int getChildCount()

Description copied from class: UIComponent

Return the number of child UIComponents that are associated with this UIComponent. If there are no children, this method must return 0. The method must not cause the creation of a child component list.

规范说明:

getChildCount in class UIComponent

findComponent

public UIComponent findComponent(String expr)

Description copied from class: UIComponent

Search for and return the UIComponent with an id that matches the specified search expression (if any), according to the algorithm described below.

For a method to find a component given a simple clientId, see UIComponent.invokeOnComponent(javax.faces.context.FacesContext, java.lang.String, javax.faces.component.ContextCallback).

Component identifiers are required to be unique within the scope of the closest ancestor NamingContainer that encloses this component (which might be this component itself). If there are no NamingContainer components in the ancestry of this component, the root component in the tree is treated as if it were a NamingContainer, whether or not its class actually implements the NamingContainer interface.

A search expression consists of either an identifier (which is matched exactly against the id property of a UIComponent, or a series of such identifiers linked by the NamingContainer.SEPARATOR_CHAR character value. The search algorithm should operates as follows, though alternate alogrithms may be used as long as the end result is the same:

• Identify the UIComponent that will be the base for searching, by stopping as soon as one of the following conditions is met:
  • If the search expression begins with the the separator character (called an "absolute" search expression), the base will be the root UIComponent of the component tree. The leading separator character will be stripped off, and the remainder of the search expression will be treated as a "relative" search expression as described below.
  • Otherwise, if this UIComponent is a NamingContainer it will serve as the basis.
  • Otherwise, search up the parents of this component. If a NamingContainer is encountered, it will be the base.
  • Otherwise (if no NamingContainer is encountered) the root UIComponent will be the base.
• The search expression (possibly modified in the previous step) is now a "relative" search expression that will be used to locate the component (if any) that has an id that matches, within the scope of the base component. The match is performed as follows:
  • If the search expression is a simple identifier, this value is compared to the id property, and then recursively through the facets and children of the base UIComponent (except that if a descendant NamingContainer is found, its own facets and children are not searched).
  • If the search expression includes more than one identifier separated by the separator character, the first identifier is used to locate a NamingContainer by the rules in the previous bullet point. Then, the findComponent() method of this NamingContainer will be called, passing the remainder of the search expression.

规范说明:

findComponent in class UIComponent

参数:

expr - Search expression identifying the UIComponent to be returned

返回:

the found UIComponent, or null if the component was not found.

抛出异常:

NullPointerException - if expr is null

invokeOnComponent

public boolean invokeOnComponent(FacesContext context,
                                 String clientId,
                                 ContextCallback callback)
                          throws FacesException

Starting at this component in the View hierarchy, search for a component with a clientId equal to the argument clientId and, if found, call the ContextCallback.invokeContextCallback(javax.faces.context.FacesContext, javax.faces.component.UIComponent) method on the argument callback, passing the current FacesContext and the found component as arguments. This method is similar to UIComponent.findComponent(java.lang.String) but it does not support the leading NamingContainer.SEPARATOR_CHAR syntax for searching from the root of the View.

The default implementation will first check if this.getClientId() is equal to the argument clientId. If so, call the ContextCallback.invokeContextCallback(javax.faces.context.FacesContext, javax.faces.component.UIComponent) method on the argument callback, passing through the FacesContext argument and passing this as the component argument. If an Exception is thrown by the callback, wrap it in a FacesException and re-throw it. Otherwise, return true.

Otherwise, for each component returned by UIComponent.getFacetsAndChildren(), call invokeOnComponent() passing the arguments to this method, in order. The first time invokeOnComponent() returns true, abort traversing the rest of the Iterator and return true.

When calling ContextCallback.invokeContextCallback(javax.faces.context.FacesContext, javax.faces.component.UIComponent) the implementation of this method must guarantee that the state of the component passed to the callback correctly reflects the component's position in the View hierarchy with respect to any state found in the argument clientId. For example, an iterating component such as UIData will need to set its row index to correctly reflect the argument clientId before finding the appropriate child component backed by the correct row. When the callback returns, either normally or by throwing an Exception the implementation of this method must restore the state of the view to the way it was before invoking the callback.

If none of the elements from UIComponent.getFacetsAndChildren() returned true from invokeOnComponent(), return false.

Simple usage example to find a component by clientId.

private UIComponent found = null;

private void doFind(FacesContext context, String clientId) {
  context.getViewRoot().invokeOnComponent(context, clientId,
      new ContextCallback() {
         public void invokeOnComponent(FacesContext context,
                                       UIComponent component) {
           found = component;
         }
      });
}
 

重写:

invokeOnComponent in class UIComponent

参数:

context - the FacesContext for the current request

clientId - the client identifier of the component to be passed to the argument callback.

callback - an implementation of the Callback interface.

返回:

true if the a component with the given clientId is found, the callback method was successfully invoked passing that component as an argument, and no Exception was thrown. Returns false if no component with the given clientId is found.

抛出异常:

NullPointerException - if any of the arguments are null

FacesException - if the argument Callback throws an Exception, it is wrapped in a FacesException and re-thrown.

从以下版本开始:

1.2

getFacets

public Map<String,UIComponent> getFacets()

Description copied from class: UIComponent

Return a mutable Map representing the facet UIComponents associated with this UIComponent, keyed by facet name (which must be a String). The returned implementation must support all of the standard and optional Map methods, plus support the following additional requirements:

• The Map implementation must implement the java.io.Serializable interface.
• Any attempt to add a null key or value must throw a NullPointerException.
• Any attempt to add a key that is not a String must throw a ClassCastException.
• Any attempt to add a value that is not a UIComponent must throw a ClassCastException.
• Whenever a new facet UIComponent is added:
  • The parent property of the component must be set to this component instance.
  • If the parent property of the component was already non-null, the component must first be removed from its previous parent (where it may have been either a child or a facet).
• Whenever an existing facet UIComponent is removed:
  • The parent property of the facet must be set to null.

规范说明:

getFacets in class UIComponent

getFacetCount

public int getFacetCount()

Description copied from class: UIComponent

Return the number of facet UIComponents that are associated with this UIComponent. If there are no facets, this method must return 0. The method must not cause the creation of a facet component map.

For backwards compatability with classes that extend UIComponent directly, a default implementation is provided that simply calls UIComponent.getFacets() and then calls the size() method on the returned Map. A more optimized version of this method is provided in getFacetCount().

重写:

getFacetCount in class UIComponent

getFacet

public UIComponent getFacet(String name)

Description copied from class: UIComponent

Convenience method to return the named facet, if it exists, or null otherwise. If the requested facet does not exist, the facets Map must not be created.

规范说明:

getFacet in class UIComponent

参数:

name - Name of the desired facet

getFacetsAndChildren

public Iterator<UIComponent> getFacetsAndChildren()

Description copied from class: UIComponent

Return an Iterator over the facet followed by child UIComponents of this UIComponent. Facets are returned in an undefined order, followed by all the children in the order they are stored in the child list. If this component has no facets or children, an empty Iterator is returned.

The returned Iterator must not support the remove() operation.

规范说明:

getFacetsAndChildren in class UIComponent

broadcast

public void broadcast(FacesEvent event)
               throws AbortProcessingException

Description copied from class: UIComponent

Broadcast the specified FacesEvent to all registered event listeners who have expressed an interest in events of this type. Listeners are called in the order in which they were added.

规范说明:

broadcast in class UIComponent

参数:

event - The FacesEvent to be broadcast

抛出异常:

AbortProcessingException - Signal the JavaServer Faces implementation that no further processing on the current event should be performed

IllegalStateException

NullPointerException - if event is null

decode

public void decode(FacesContext context)

Description copied from class: UIComponent

Decode any new state of this UIComponent from the request contained in the specified FacesContext, and store this state as needed.

During decoding, events may be enqueued for later processing (by event listeners who have registered an interest), by calling queueEvent().

规范说明:

decode in class UIComponent

参数:

context - FacesContext for the request we are processing

抛出异常:

NullPointerException - if context is null

encodeBegin

public void encodeBegin(FacesContext context)
                 throws IOException

Description copied from class: UIComponent

If our rendered property is true, render the beginning of the current state of this UIComponent to the response contained in the specified FacesContext.

If a Renderer is associated with this UIComponent, the actual encoding will be delegated to Renderer.encodeBegin(FacesContext, UIComponent).

规范说明:

encodeBegin in class UIComponent

参数:

context - FacesContext for the response we are creating

抛出异常:

NullPointerException - if context is null

IOException - if an input/output error occurs while rendering

encodeChildren

public void encodeChildren(FacesContext context)
                    throws IOException

Description copied from class: UIComponent

If our rendered property is true, render the child UIComponents of this UIComponent. This method will only be called if the rendersChildren property is true.

If a Renderer is associated with this UIComponent, the actual encoding will be delegated to Renderer.encodeChildren(FacesContext, UIComponent).

规范说明:

encodeChildren in class UIComponent

参数:

context - FacesContext for the response we are creating

抛出异常:

NullPointerException - if context is null

IOException - if an input/output error occurs while rendering

encodeEnd

public void encodeEnd(FacesContext context)
               throws IOException

Description copied from class: UIComponent

If our rendered property is true, render the ending of the current state of this UIComponent.

If a Renderer is associated with this UIComponent, the actual encoding will be delegated to Renderer.encodeEnd(FacesContext, UIComponent).

规范说明:

encodeEnd in class UIComponent

参数:

context - FacesContext for the response we are creating

抛出异常:

IOException - if an input/output error occurs while rendering

NullPointerException - if context is null

addFacesListener

protected void addFacesListener(FacesListener listener)

Add the specified FacesListener to the set of listeners registered to receive event notifications from this UIComponent. It is expected that UIComponent classes acting as event sources will have corresponding typesafe APIs for registering listeners of the required type, and the implementation of those registration methods will delegate to this method. For example:

 public class FooEvent extends FacesEvent {
   ...
   protected boolean isAppropriateListener(FacesListener listener) {
     return (listener instanceof FooListener);
   }
   protected void processListener(FacesListener listener) {
     ((FooListener) listener).processFoo(this);
   }
   ...
 }

 public interface FooListener extends FacesListener {
   public void processFoo(FooEvent event);
 }

 public class FooComponent extends UIComponentBase {
   ...
   public void addFooListener(FooListener listener) {
     addFacesListener(listener);
   }
   public void removeFooListener(FooListener listener) {
     removeFacesListener(listener);
   }
   ...
 }
 

规范说明:

addFacesListener in class UIComponent

参数:

listener - The FacesListener to be registered

抛出异常:

NullPointerException - if listener is null

getFacesListeners

protected FacesListener[] getFacesListeners(Class clazz)

Description copied from class: UIComponent

Return an array of registered FacesListeners that are instances of the specified class. If there are no such registered listeners, a zero-length array is returned. The returned array can be safely be cast to an array strongly typed to an element type of clazz.

规范说明:

getFacesListeners in class UIComponent

参数:

clazz - Class that must be implemented by a FacesListener for it to be returned

抛出异常:

IllegalArgumentException - if class is not, and does not implement, FacesListener

NullPointerException - if clazz is null

removeFacesListener

protected void removeFacesListener(FacesListener listener)

Remove the specified FacesListener from the set of listeners registered to receive event notifications from this UIComponent.

规范说明:

removeFacesListener in class UIComponent

参数:

listener - The FacesListener to be deregistered

抛出异常:

NullPointerException - if listener is null

queueEvent

public void queueEvent(FacesEvent event)

Description copied from class: UIComponent

Queue an event for broadcast at the end of the current request processing lifecycle phase. The default implementation in UIComponentBase must delegate this call to the queueEvent() method of the parent UIComponent.

规范说明:

queueEvent in class UIComponent

参数:

event - FacesEvent to be queued

抛出异常:

IllegalStateException - if this component is not a descendant of a UIViewRoot

NullPointerException - if event is null

processDecodes

public void processDecodes(FacesContext context)

Description copied from class: UIComponent

Perform the component tree processing required by the Apply Request Values phase of the request processing lifecycle for all facets of this component, all children of this component, and this component itself, as follows.

• If the rendered property of this UIComponent is false, skip further processing.
• Call the processDecodes() method of all facets and children of this UIComponent, in the order determined by a call to getFacetsAndChildren().
• Call the decode() method of this component.
• If a RuntimeException is thrown during decode processing, call FacesContext.renderResponse() and re-throw the exception.

规范说明:

processDecodes in class UIComponent

参数:

context - FacesContext for the request we are processing

抛出异常:

NullPointerException - if context is null

processValidators

public void processValidators(FacesContext context)

Description copied from class: UIComponent

Perform the component tree processing required by the Process Validations phase of the request processing lifecycle for all facets of this component, all children of this component, and this component itself, as follows.

• If the rendered property of this UIComponent is false, skip further processing.
• Call the processValidators() method of all facets and children of this UIComponent, in the order determined by a call to getFacetsAndChildren().

规范说明:

processValidators in class UIComponent

参数:

context - FacesContext for the request we are processing

抛出异常:

NullPointerException - if context is null

processUpdates

public void processUpdates(FacesContext context)

Description copied from class: UIComponent

Perform the component tree processing required by the Update Model Values phase of the request processing lifecycle for all facets of this component, all children of this component, and this component itself, as follows.

• If the rendered property of this UIComponent is false, skip further processing.
• Call the processUpdates() method of all facets and children of this UIComponent, in the order determined by a call to getFacetsAndChildren().

规范说明:

processUpdates in class UIComponent

参数:

context - FacesContext for the request we are processing

抛出异常:

NullPointerException - if context is null

processSaveState

public Object processSaveState(FacesContext context)

Description copied from class: UIComponent

Perform the component tree processing required by the state saving portion of the Render Response phase of the request processing lifecycle for all facets of this component, all children of this component, and this component itself, as follows.

• consult the transient property of this component. If true, just return null.
• Call the processSaveState() method of all facets and children of this UIComponent in the order determined by a call to getFacetsAndChildren(), skipping children and facets that are transient.
• Call the saveState() method of this component.
• Encapsulate the child state and your state into a Serializable Object and return it.

This method may not be called if the state saving method is set to server.

规范说明:

processSaveState in class UIComponent

参数:

context - FacesContext for the request we are processing

抛出异常:

NullPointerException - if context is null

processRestoreState

public void processRestoreState(FacesContext context,
                                Object state)

Description copied from class: UIComponent

Perform the component tree processing required by the Restore View phase of the request processing lifecycle for all facets of this component, all children of this component, and this component itself, as follows.

• Call the processRestoreState() method of all facets and children of this UIComponent in the order determined by a call to getFacetsAndChildren().
• Call the restoreState() method of this component.

This method may not be called if the state saving method is set to server.

规范说明:

processRestoreState in class UIComponent

参数:

context - FacesContext for the request we are processing

抛出异常:

NullPointerException - if context is null

getFacesContext

protected FacesContext getFacesContext()

Description copied from class: UIComponent

Convenience method to return the FacesContext instance for the current request.

规范说明:

getFacesContext in class UIComponent

getRenderer

protected Renderer getRenderer(FacesContext context)

Description copied from class: UIComponent

Convenience method to return the Renderer instance associated with this component, if any; otherwise, return null.

规范说明:

getRenderer in class UIComponent

参数:

context - FacesContext for the current request

saveState

public Object saveState(FacesContext context)

Description copied from interface: StateHolder

Gets the state of the instance as a Serializable Object.

If the class that implements this interface has references to instances that implement StateHolder (such as a UIComponent with event handlers, validators, etc.) this method must call the StateHolder.saveState(javax.faces.context.FacesContext) method on all those instances as well. This method must not save the state of children and facets. That is done via the StateManager

This method must not alter the state of the implementing object. In other words, after executing this code:

 Object state = component.saveState(facesContext);
 

component should be the same as before executing it.

The return from this method must be Serializable

public void restoreState(FacesContext context,
                         Object state)

public boolean isTransient()

public void setTransient(boolean transientFlag)

public static Object saveAttachedState(FacesContext context,
                                       Object attachedObject)

public static Object restoreAttachedState(FacesContext context,
                                          Object stateObj)
                                   throws IllegalStateException