com.portal.bas

Class PModelHandle

java.lang.Object

com.portal.bas.PModelHandle

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

PCollectingModelHandle

public class PModelHandle
extends Object
implements Serializable

PModelHandle passes a reference to a database object: basically, a handle to an flist, whether that flist is an opcode return value, a POID member of another flist, a substruct, or an array element. Because it is a handle, it may not have actually been read from the Portal database yet, so calls to access fields must make a connection.

A model handle provides a hash value: however, it can also be typed to indicate the type of the object it refers to. Also, when a model handle is created from a POID, it is very useful to use the POID's type as the handle's type and the POID's ID as the hash value. However, the POID's ID is a different size than provided by Object.hashCode(). To re-create the original POID from the model handle, the full value is needed, which is why there are two hash methods included in this class.

Version:

5

Author:

Larry Lynch-Freshner

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static int	LOOKUP_DONT_UPDATE
static int	LOOKUP_FORCE_UPDATE
static int	LOOKUP_UPDATE_IF_NEEDED
static String	UNTYPED A constant that provides a default value for creating an untyped model handle.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PModelHandle() Creates a model handle by assigning it a simple seed value.
protected	PModelHandle(PModelHandle mh) Copies a model handle.
protected	PModelHandle(String type, long hash, boolean hashGiven, Object model) Initializes the model handle with type, hash, and hashGiven.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object other) Overrides Object.equals.
long	getHash() Gets the actual hashCode (a long).
Object	getModel()
String	getType() Returns the type of model.
int	hashCode() Gets the hash value.
boolean	isGivenHash() Tests to determine if the handle was given the hash value to use.
String	toString() Gets a string representation of the model.

Methods inherited from class java.lang.Object

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

Field Detail

UNTYPED

public static final String UNTYPED

A constant that provides a default value for creating an untyped model handle.

See Also:

Constant Field Values

LOOKUP_UPDATE_IF_NEEDED

public static final int LOOKUP_UPDATE_IF_NEEDED

See Also:

Constant Field Values

LOOKUP_FORCE_UPDATE

public static final int LOOKUP_FORCE_UPDATE

See Also:

Constant Field Values

LOOKUP_DONT_UPDATE

public static final int LOOKUP_DONT_UPDATE

See Also:

Constant Field Values

Constructor Detail

PModelHandle

protected PModelHandle()

Creates a model handle by assigning it a simple seed value.

PModelHandle

protected PModelHandle(PModelHandle mh)

Copies a model handle.

Parameters:

mh - the model handle to copy

PModelHandle

protected PModelHandle(String type,
                       long hash,
                       boolean hashGiven,
                       Object model)

Initializes the model handle with type, hash, and hashGiven. This is the ctor that all other ctors call.

Method Detail

getType

public String getType()

Returns the type of model. May correspond to database type.

Returns:

A String that defines the type of model.

hashCode

public int hashCode()

Gets the hash value. Called by collection using hashing. This produces a valid hash value even if the internal number is a different size. Overrides Object.hashCode().

Overrides:

hashCode in class Object

Returns:

The hash value.

getHash

public long getHash()

Gets the actual hashCode (a long). This is usually called by the framework when re-creating a POID from a model handle.

Returns:

The hashCode.

isGivenHash

public boolean isGivenHash()

Tests to determine if the handle was given the hash value to use. For example, it returns true if the handle was created from a POID.

Returns:

True if the handle was given the hash value to use; false otherwise.

getModel

public Object getModel()

equals

public boolean equals(Object other)

Overrides Object.equals. Used as an equality test.

Overrides:

equals in class Object

Parameters:

other - the Object to test against

Returns:

True if equal; false otherwise.

toString

public String toString()

Gets a string representation of the model.

Overrides:

toString in class Object

Returns:

The model's String representation.