com.sun.faces.renderkit

Class ResponseStateManagerImpl

java.lang.Object

javax.faces.render.ResponseStateManager

com.sun.faces.renderkit.ResponseStateManagerImpl

public class ResponseStateManagerImpl
extends ResponseStateManager

A ResonseStateManager implementation for the default HTML render kit.

Field Summary

Fields inherited from class javax.faces.render.ResponseStateManager

CLIENT_WINDOW_PARAM, CLIENT_WINDOW_URL_PARAM, NON_POSTBACK_VIEW_TOKEN_PARAM, RENDER_KIT_ID_PARAM, VIEW_STATE_PARAM

Constructor Summary

Constructors

Constructor and Description
ResponseStateManagerImpl()

Method Summary

Modifier and Type	Method and Description
String	getCryptographicallyStrongTokenFromSession(FacesContext context) Compliant implementations must return a cryptographically strong token for use to protect views in this application.
Object	getState(FacesContext context, String viewId) The implementation must inspect the current request and return an Object representing the tree structure and component state passed in to a previous invocation of ResponseStateManager.writeState(javax.faces.context.FacesContext,java.lang.Object).
Object	getTreeStructureToRestore(FacesContext context, String viewId) The implementation must inspect the current request and return the tree structure Object passed to it on a previous invocation of writeState().
String	getViewState(FacesContext context, Object state) Return the specified state as a String without any markup related to the rendering technology supported by this ResponseStateManager.
boolean	isPostback(FacesContext context) Return true if the current request is a postback.
boolean	isStateless(FacesContext facesContext, String viewId) If the preceding call to ResponseStateManager.writeState(javax.faces.context.FacesContext, java.lang.Object) was stateless, return true.
void	writeState(FacesContext context, Object state) Take the argument state and write it into the output using the current ResponseWriter, which must be correctly positioned already.

Methods inherited from class javax.faces.render.ResponseStateManager

getComponentStateToRestore, writeState

Methods inherited from class java.lang.Object

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

Constructor Detail

ResponseStateManagerImpl

public ResponseStateManagerImpl()

Method Detail

isPostback

public boolean isPostback(FacesContext context)

Description copied from class: ResponseStateManager

Return true if the current request is a postback. This method is leveraged from the Restore View Phase to determine if ViewHandler.restoreView(javax.faces.context.FacesContext, java.lang.String) or ViewHandler.createView(javax.faces.context.FacesContext, java.lang.String) should be called. The default implementation must return true if this ResponseStateManager instance wrote out state on a previous request to which this request is a postback, false otherwise.

The implementation of this method for the Standard HTML RenderKit must consult the ExternalContext's requestParameterMap and return true if and only if there is a key equal to the value of the symbolic constant ResponseStateManager.VIEW_STATE_PARAM.

For backwards compatibility with implementations of ResponseStateManager prior to Jakarta Server Faces 1.2, a default implementation is provided that consults the ExternalContext's requestParameterMap and return true if its size is greater than 0.

Overrides:

isPostback in class ResponseStateManager

Parameters:

context - the FacesContext for the current request.

Returns:

the value as specified above

See Also:

ResponseStateManager.isPostback(javax.faces.context.FacesContext)

getCryptographicallyStrongTokenFromSession

public String getCryptographicallyStrongTokenFromSession(FacesContext context)

Description copied from class: ResponseStateManager

Compliant implementations must return a cryptographically strong token for use to protect views in this application. For backwards compatability with earlier revisions, a default implementation is provided that simply returns null.

Overrides:

getCryptographicallyStrongTokenFromSession in class ResponseStateManager

Parameters:

context - the FacesContext for the current request

Returns:

a cryptographically strong value

getState

public Object getState(FacesContext context,
                       String viewId)

Description copied from class: ResponseStateManager

The implementation must inspect the current request and return an Object representing the tree structure and component state passed in to a previous invocation of ResponseStateManager.writeState(javax.faces.context.FacesContext,java.lang.Object).

If the state saving method for this application is StateManager.STATE_SAVING_METHOD_CLIENT, writeState() will have encrypted the state in a tamper evident manner. If the state fails to decrypt, or decrypts but indicates evidence of tampering, a ProtectedViewException must be thrown.

For backwards compatability with existing ResponseStateManager implementations, the default implementation of this method calls ResponseStateManager.getTreeStructureToRestore(javax.faces.context.FacesContext, java.lang.String) and ResponseStateManager.getComponentStateToRestore(javax.faces.context.FacesContext) and creates and returns a two element Object array with element zero containing the structure property and element one containing the state property of the SerializedView.

Overrides:

getState in class ResponseStateManager

Parameters:

context - The FacesContext instance for the current request

viewId - View identifier of the view to be restored

Returns:

the tree structure and component state Object passed in to writeState. If this is an initial request, this method returns null.

See Also:

ResponseStateManager.getState(javax.faces.context.FacesContext, java.lang.String)

writeState

public void writeState(FacesContext context,
                       Object state)
                throws IOException

Description copied from class: ResponseStateManager

Take the argument state and write it into the output using the current ResponseWriter, which must be correctly positioned already.

Call FacesContext.getViewRoot(). If StateHolder.isTransient() returns true, take implementation specific action so that the following call to ResponseStateManager.isStateless(javax.faces.context.FacesContext, java.lang.String) returns true and return. Otherwise, proceed as follows.

If the state is to be written out to hidden fields, the implementation must take care to make all necessary character replacements to make the Strings suitable for inclusion as an HTTP request paramater.

If the state saving method for this application is StateManager.STATE_SAVING_METHOD_CLIENT, the implementation must encrypt the state to be saved to the client in a tamper evident manner.

If the state saving method for this application is StateManager.STATE_SAVING_METHOD_SERVER, and the current request is an Ajax request PartialViewContext.isAjaxRequest() returns true), use the current view state identifier if it is available (do not generate a new identifier).

Write out the render kit identifier associated with this ResponseStateManager implementation with the name as the value of the String constant ResponseStateManager.RENDER_KIT_ID_PARAM. The render kit identifier must not be written if:

• it is the default render kit identifier as returned by Application.getDefaultRenderKitId() or
• the render kit identfier is the value of javax.faces.render.RenderKitFactory.HTML_BASIC_RENDER_KIT and Application.getDefaultRenderKitId() returns null.

For backwards compatability with existing ResponseStateManager implementations, the default implementation of this method checks if the argument is an instance of SerializedView. If so, it calls through to ResponseStateManager.writeState(javax.faces.context.FacesContext,javax.faces.application.StateManager.SerializedView). If not, it expects the state to be a two element Object array. It creates an instance of SerializedView and stores the state as the treeStructure, and passes it to ResponseStateManager.writeState(javax.faces.context.FacesContext,javax.faces.application.StateManager.SerializedView).

The ClientWindow must be written using these steps. Call ExternalContext.getClientWindow(). If the result is null, take no further action regarding the ClientWindow. If the result is non-null, write a hidden field whose name is ResponseStateManager.CLIENT_WINDOW_PARAM and whose id is <VIEW_ROOT_CONTAINER_CLIENT_ID><SEP>javax.faces.ClientWindow<SEP><UNIQUE_PER_VIEW_NUMBER> where <SEP> is the currently configured UINamingContainer.getSeparatorChar(). <VIEW_ROOT_CONTAINER_CLIENT_ID> is the return from UIViewRoot.getContainerClientId() on the view from whence this state originated. <UNIQUE_PER_VIEW_NUMBER> is a number that must be unique within this view, but must not be included in the view state. The value of the field is implementation dependent but must uniquely identify this window within the user's session.

Overrides:

writeState in class ResponseStateManager

Parameters:

context - The FacesContext instance for the current request

state - The serialized state information previously saved

Throws:

IOException - if the state argument is not an array of length 2.

See Also:

ResponseStateManager.writeState(javax.faces.context.FacesContext, java.lang.Object)

getViewState

public String getViewState(FacesContext context,
                           Object state)

Description copied from class: ResponseStateManager

Return the specified state as a String without any markup related to the rendering technology supported by this ResponseStateManager.

Overrides:

getViewState in class ResponseStateManager

Parameters:

context - the FacesContext for the current request

state - the state from which the String version will be generated from

Returns:

the view state for this request without any markup specifics

See Also:

ResponseStateManager.getViewState(javax.faces.context.FacesContext, java.lang.Object)

getTreeStructureToRestore

public Object getTreeStructureToRestore(FacesContext context,
                                        String viewId)

Description copied from class: ResponseStateManager

The implementation must inspect the current request and return the tree structure Object passed to it on a previous invocation of writeState().

Overrides:

getTreeStructureToRestore in class ResponseStateManager

Parameters:

context - The FacesContext instance for the current request

viewId - View identifier of the view to be restored

Returns:

the tree structure portion of the state

isStateless

public boolean isStateless(FacesContext facesContext,
                           String viewId)

Description copied from class: ResponseStateManager

If the preceding call to ResponseStateManager.writeState(javax.faces.context.FacesContext, java.lang.Object) was stateless, return true. If the preceding call to writeState() was stateful, return false. Otherwise throw IllegalStateException.

To preserve backward compatibility with custom implementations that may have extended from an earlier version of this class, an implementation is provided that returns false. A compliant implementation must override this method to take the specified action.

Overrides:

isStateless in class ResponseStateManager

Parameters:

facesContext - the Faces context.

viewId - the view id.

Returns:

true if "stateless" was found, false otherwise.

Throws:

IllegalStateException - when the request is not a postback.