oracle.jbo.server
Class ViewRowImpl

java.lang.Object
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  +--oracle.jbo.common.BaseObject
        |
        +--oracle.jbo.server.RowImpl
              |
              +--oracle.jbo.server.ViewRowImpl

Direct Known Subclasses:

EJBEntityImpl

public class ViewRowImpl

extends RowImpl

implements Row

A View Object Row. This class provides access to a View Object Row. The View Object Row can contain one or more Entity Object Rows in addition to derived attributes such as calculated columns.

The Business Components for Java framework instantiates an object of this class for each record that is returned by the row's View Object query. This class can be referred to by middle-tier customer application logic in order to access View Object Row data.

Customers can extend this class with custom View Object Row implementations. For example, the Business Components for Java View Object wizard can be used to generate sub-classes of this class that define type-safe accessors/mutators for the attributes of a row. Custom sub-classes should be declard to the Business Components for Java framework through the View Object wizard.

Customer applications should not access this class on the client-tier of an application. Instead, the Row interface should be used for client tier access.

Since:

JDeveloper 3.0

See Also:

RowImpl, Row

Field Summary

static java.lang.String	XML_POSTSTATE_REMOVE
static java.lang.String	XML_POSTSTATE_TAG

Fields inherited from class oracle.jbo.common.BaseObject

TRACE_EVERY_ALLOC, TRACE_NONE, TRACE_OCCASIONAL, TRACE_UNINITIALIZED

Fields inherited from interface oracle.jbo.XMLInterface

XML_OPT_ALL_ROWS, XML_OPT_ASSOC_CONSISTENT, XML_OPT_CHANGES_ONLY, XML_OPT_LIMIT_RANGE

Constructor Summary

ViewRowImpl()
Public constructor for this class.

Method Summary

protected void	appendXMLElementNodes(org.w3c.dom.Document xmlDoc, org.w3c.dom.Node node, int depthCount, long options, AttributeDefImpl[] attrs) Writes XML-element nodes for each attribute in this row and appends it to the given row-node.
protected void	create(AttributeList nvp) Initialization method to be over-ridden in generated code for custom defaulting.
protected EntityImpl[]	createEntities() Creates blank instances of the Entity Objects that this row is composed of.
boolean	equals(java.lang.Object other) Tests if the specified value is equal to this ViewRowImpl object.
protected RowSet	findAssociatedObjects(java.lang.String name) Finds Objects in a ViewRowSetImpl that follow the given association.
ApplicationModule	getApplicationModule() Gets the Application Module to which the containing View Object belongs.
java.lang.Object	getAttribute(int ix) Selects the attribute at the given index.
java.lang.Object	getAttribute(java.lang.String name) Gets the value of an attribute by name.
int	getAttributeCount() Gets the attribute count in this ViewRow.
int	getAttributeIndexOf(java.lang.String alias) Gets the index of the attribute, given it's name.
protected java.lang.Object	getAttributeInternal(int index) Gets the value of the attribute by index.
protected EntityImpl	getEntity(int index) Gets the Entity at the given index.
Entity	getEntityForAttribute(java.lang.String attrName) Gets an entity object that contains the given attribute name.
java.lang.Object	getHandle() Creates a row identifier that is unique in the query collection.
Key	getKey() Returns the identifier object for this row.
QueryCollection	getQueryCollection(java.lang.Object accessKey) Gets the QueryCollection this row exists in.
ViewObject	getViewObject() Gets the View Object to which this row belongs.
protected java.lang.String	getXMLElementTag() Returns the XML-element tag for this row.
int	hashCode() Computes an integer hash code for this ViewRowImpl object
boolean	isAttributeUpdateable(int index) Tests if an attribute is updateable.
void	lock() Locks the referenced Entity Rows.
protected void	populate(java.sql.ResultSet resultSet) Internal: Applications should not use this method.
protected void	populateAttribute(int index, java.lang.Object value)
protected void	populateAttributeAsChanged(int index, java.lang.Object value)
protected void	readAttributeFromXMLElement(org.w3c.dom.Node rowElt, AttributeDefImpl ad)
void	readXML(org.w3c.dom.Element rowElt, int depthCount) Reads the content of the row and updates the attributes, from given XML document.
void	remove() Deletes the row.
protected org.w3c.dom.Element	renderAttributeInXMLElement(org.w3c.dom.Document xmlDoc, AttributeDefImpl ad, boolean explicitNull)
void	revert() Reverts this row back to its initial state.
void	setAttribute(int index, java.lang.Object val) Sets an attribute.
void	setAttribute(java.lang.String name, java.lang.Object val) Sets the value of an attribute by name.
protected void	setAttributeInternal(int index, java.lang.Object val) This is an "inner" accessor for an attribute and does not call out to the getXXX() method.
protected void	setEntities(EntityImpl[] rows) Sets the entities that this view row is composed of.
void	validate() Calls validate on each this view row's Entity Objects.

Methods inherited from class oracle.jbo.server.RowImpl

createXMLDefinition, getAttributeInternal, printXMLDefinition, readXML, setAttributeInternal, writeXML, writeXML

Methods inherited from class oracle.jbo.common.BaseObject

dumpState, setTraceLevel, setTraceWriter

Methods inherited from class java.lang.Object

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

Field Detail

XML_POSTSTATE_TAG

public static final java.lang.String XML_POSTSTATE_TAG

XML_POSTSTATE_REMOVE

public static final java.lang.String XML_POSTSTATE_REMOVE

Constructor Detail

ViewRowImpl

public ViewRowImpl()

Public constructor for this class.

Method Detail

create

protected void create(AttributeList nvp)

Initialization method to be over-ridden in generated code for custom defaulting.

This method invokes create(AttributeList) on each of the "new" entities that make up this View Row.

The attribute list nvp is simply passed to the new entity rows that make up this View Row.

Note: the names in the attribute list are not transformed into entity-relative names hoping that the caller has done so already. If not, the entity's create() method might fail.

Overrides:

create in class RowImpl

Parameters:

nvp - the list of attributtes.

getQueryCollection

public QueryCollection getQueryCollection(java.lang.Object accessKey)

Gets the QueryCollection this row exists in.

Returns:

the QueryCollection that the row exists in.

getHandle

public java.lang.Object getHandle()

Creates a row identifier that is unique in the query collection.

Each row in a collection can be identified by either its Java object reference or by its row handle. The row handle, together with the collection name, forms an identifier that can be stored externally, in order to identify the row in future operations.

Applications should not rely on indentifier having a specific format: it is subject to change.

A row handle can be converted to a string using toString() methods, and compared using equals

Returns:

a unique row identifier.

getKey

public Key getKey()

Returns the identifier object for this row.

Specified by:

getKey in interface Row

Overrides:

getKey in class RowImpl

Returns:

the key of the row.

validate

public void validate()

Calls validate on each this view row's Entity Objects.

Specified by:

validate in interface Row

Overrides:

validate in class RowImpl

Throws:

JboException - if validation fails.

getAttributeInternal

protected java.lang.Object getAttributeInternal(int index)

Gets the value of the attribute by index. If the attribute is mapped to an entity-attribute, invoke that entity.getAttribute() with the mapped index. For all other attributes, return the value from the ViewRow's storage.

Note that this is an "inner" accessor for an attribute and does not callout to the generated getXXX() method on a subclass of a ViewRowImpl. getAttribute() methods are the "outer" methods that callout to a subclass's getXXX() method where XXX is the name of the attribute.

Overrides:

getAttributeInternal in class RowImpl

Parameters:

index - the index of the attribute.

Returns:

the value of the column at the index.

getAttribute

public java.lang.Object getAttribute(int ix)

Description copied from interface: AttributeList

Selects the attribute at the given index.

Tags copied from interface: AttributeList

Parameters:

index - an integer in the range 0 to getAttributeCount() - 1.

Returns:

the attribute associated with index.

getAttribute

public final java.lang.Object getAttribute(java.lang.String name)

Gets the value of an attribute by name.

Parameters:

name - the name of the attribute.

Returns:

the value of the attribute.

setAttribute

public final void setAttribute(java.lang.String name,
                               java.lang.Object val)

Sets the value of an attribute by name.

Parameters:

name - the name of the attribute.

val - the value of the attribute.

setAttribute

public void setAttribute(int index,
                         java.lang.Object val)

Sets an attribute.

This method performs a type-check on the value, so that it matches the Java type of the attribute.

Parameters:

index - the index of the attribute.

val - the new value.

Throws:

ReadOnlyAttrException - if the attribute is not updateable.

InvalidOperException - if this row belongs is to a forward-only View Object.

DataCreationException - if the given value is not convertible to the Java type of the attribute.

AttrSetValException - if any validation logic fails while setting this attribute to the mapped Entity Object attribute.

setAttributeInternal

protected void setAttributeInternal(int index,
                                    java.lang.Object val)

This is an "inner" accessor for an attribute and does not call out to the getXXX() method. This method sets the value to the mapping entity attribute or stores the value in ViewRow cache for the given attribute.

This method also does not perform any type-check for the value's java type and assumes that the value-type is same as the java-type for this attribute.

Overrides:

setAttributeInternal in class RowImpl

Parameters:

index - The index of the attribute.

val - The value.

Throws:

ReadOnlyAttrException - if the attribute is not updateable.

AttrSetValException - if any validation logic fails while setting this attribute to the mapped Entity attribute.

getViewObject

public final ViewObject getViewObject()

Gets the View Object to which this row belongs.

Returns:

the View Object.

getApplicationModule

public final ApplicationModule getApplicationModule()

Gets the Application Module to which the containing View Object belongs.

Returns:

an Application Module.

getAttributeIndexOf

public int getAttributeIndexOf(java.lang.String alias)

Gets the index of the attribute, given it's name.

Overrides:

getAttributeIndexOf in class RowImpl

Parameters:

alias - the alias of the attribute.

Returns:

the attribute's index.

createEntities

protected EntityImpl[] createEntities()

Creates blank instances of the Entity Objects that this row is composed of. Advanced method used by subclasses to create their own instances of entities based on custom-logic to bypass entity-creation from the framework.

Returns:

array of EntityImpls that is then set as the array of Entities this ViewRow is composed of.

lock

public void lock()

Locks the referenced Entity Rows. This method uses the design-time View Object metadata to determine which of the Entity Rows that are referenced by the View Object are updateable and should consequently be locked.

Specified by:

lock in interface Row

Overrides:

lock in class RowImpl

Tags copied from interface: Row

Throws:

JboException - a runtime exception, if an exception occurs during access.

revert

public void revert()

Reverts this row back to its initial state. If a row is used in multiple View Objects, this operation's effect will be visible to all.

remove

public void remove()

Deletes the row. This method will invoke remove on the updateable Entity Rows that are referenced by this View Object Row. After the referenced, updateable entity rows have been removed this method will remove the View Object Row from the View Object's RowSet.

Specified by:

remove in interface Row

Overrides:

remove in class RowImpl

Tags copied from interface: Row

Throws:

JboException - a runtime exception, if an exception occurs during access.

getEntity

protected final EntityImpl getEntity(int index)

Gets the Entity at the given index. Used in generated code for viewrow to get to the attribute mapped to an entity.

Parameters:

index - the index of the Entity.

getEntityForAttribute

public final Entity getEntityForAttribute(java.lang.String attrName)

Gets an entity object that contains the given attribute name.

Parameters:

attrName - name of an attribute

Returns:

an entity object.

setEntities

protected final void setEntities(EntityImpl[] rows)

Sets the entities that this view row is composed of.

This method is called by framework, after entites are created for this row. This must be protected because subclasses can create their own entity instances and have the viewrow manage them.

For example, assume there is a ViewRow on the Doc Entity where Doc has subclasses PO and Req, the ViewRow subclass can create PO/Req instances of entities based on some logic and have ViewRow manage them as an entity of type Doc.

getAttributeCount

public final int getAttributeCount()

Gets the attribute count in this ViewRow.

Overrides:

getAttributeCount in class RowImpl

Returns:

the number of attributes.

isAttributeUpdateable

public boolean isAttributeUpdateable(int index)

Description copied from interface: Row

Tests if an attribute is updateable.

Specified by:

isAttributeUpdateable in interface Row

Overrides:

isAttributeUpdateable in class RowImpl

Tags copied from interface: Row

Parameters:

index - the index of the attribute.

Returns:

true if the row is marked UPDATEABLE, or if the row is marked UPDATEABLE_WHILE_NEW and the current row is new.

populate

protected void populate(java.sql.ResultSet resultSet)

Internal: Applications should not use this method.

Populate this row from the ResultSet.

This is a Framework-internal method. This method is used to fill in entity-attributes from a JDBC ResultSet that is returned by executeQuery().

Note that the method works on the current row of the result set and any currecy change on the ResultSet could throw it off. This method is protected to let sub-ViewRows fill in custom-entities created based on data.

For example, if fax is a subtype of doc and based on a column value, either doc is created or a fax is created for a given entity type, this method may be used to create entities based on the data values. Note that the developer needs to know exact position of values in the JDBC ResultSet.

Parameters:

resultSet - the JDBC ResultSet containing the row data.

populateAttribute

protected void populateAttribute(int index,
                                 java.lang.Object value)

Overrides:

populateAttribute in class RowImpl

populateAttributeAsChanged

protected void populateAttributeAsChanged(int index,
                                          java.lang.Object value)

findAssociatedObjects

protected RowSet findAssociatedObjects(java.lang.String name)

Finds Objects in a ViewRowSetImpl that follow the given association.

Parameters:

name - that defines the association

Returns:

A set of associated object/s.

hashCode

public int hashCode()

Computes an integer hash code for this ViewRowImpl object

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code of this ViewRowImpl object.

equals

public boolean equals(java.lang.Object other)

Tests if the specified value is equal to this ViewRowImpl object.

Overrides:

equals in class java.lang.Object

Parameters:

other - the object to which the ViewRowImpl should be compared.

Returns:

true if the specified object is equal to the this ViewRowImpl.

getXMLElementTag

protected java.lang.String getXMLElementTag()

Returns the XML-element tag for this row. If no custom-property (of the name XML_ROW_ELEMENT) is found, it returns the name of the View Object + the suffix "Row". For example, "EmpViewRow".

appendXMLElementNodes

protected void appendXMLElementNodes(org.w3c.dom.Document xmlDoc,
                                     org.w3c.dom.Node node,
                                     int depthCount,
                                     long options,
                                     AttributeDefImpl[] attrs)

Writes XML-element nodes for each attribute in this row and appends it to the given row-node.

Override this method to perform custom XML-rendering on a Row.

Parameters:

xmlDoc - name of the XML document where the node resides.

node - the name of the Row object node where new nodes will be appended.

depthCount - number of child levels deep to appendrow nodes.

options - a set of bit flags that will control the writeXML behavior.

attrs - an array of AttriubuteDefImpls.

renderAttributeInXMLElement

protected org.w3c.dom.Element renderAttributeInXMLElement(org.w3c.dom.Document xmlDoc,
                                                          AttributeDefImpl ad,
                                                          boolean explicitNull)

readAttributeFromXMLElement

protected void readAttributeFromXMLElement(org.w3c.dom.Node rowElt,
                                           AttributeDefImpl ad)

readXML

public final void readXML(org.w3c.dom.Element rowElt,
                          int depthCount)

Reads the content of the row and updates the attributes, from given XML document. If there's a process instruction in the row like: <?bc4j remove?> then calls remove() on this row.

Overrides:

readXML in class RowImpl

Parameters:

rowElt - name of the XML element.

depthCount - the number of child levels deep to which data should be read.