org.datanucleus.enhancer.spi

Class SingleFieldPK

java.lang.Object

org.datanucleus.enhancer.spi.SingleFieldPK

All Implemented Interfaces:

Externalizable, Serializable, Comparable

Direct Known Subclasses:

ByteFieldPK, CharFieldPK, IntFieldPK, LongFieldPK, ObjectFieldPK, ShortFieldPK, StringFieldPK

public abstract class SingleFieldPK
extends Object
implements Externalizable, Comparable

Abstract base class for all single-field identity classes.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected int	hashCode The hashCode.
protected Object	keyAsObject The key as an Object.

Constructor Summary

Constructors

Modifier	Constructor and Description
	SingleFieldPK() Constructor only for Externalizable.
protected	SingleFieldPK(Class pcClass) Constructor with target class.

Method Summary

Methods

Modifier and Type	Method and Description
protected void	assertKeyNotNull(Object key) Assert that the key is not null.
protected Object	createKeyAsObject() Create the key as an Object.
boolean	equals(Object obj) Check the class and class name and object type.
Object	getKeyAsObject() Return the key as an Object.
Class	getTargetClass() Return the target class.
String	getTargetClassName() Return the target class name.
protected int	hashClassName() Return the hash code of the class name.
int	hashCode() Return the cached hash code.
void	readExternal(ObjectInput in) Read from the input stream.
protected void	setKeyAsObject(Object key) Set the given key as the key for this instance.
void	writeExternal(ObjectOutput out) Write to the output stream.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Comparable

compareTo

Field Detail

hashCode

protected int hashCode

The hashCode.

keyAsObject

protected Object keyAsObject

The key as an Object.

Constructor Detail

SingleFieldPK

protected SingleFieldPK(Class pcClass)

Constructor with target class.

Parameters:

pcClass - the class of the target

SingleFieldPK

public SingleFieldPK()

Constructor only for Externalizable.

Method Detail

setKeyAsObject

protected void setKeyAsObject(Object key)

Set the given key as the key for this instance. Compute the hash code for the instance.

assertKeyNotNull

protected void assertKeyNotNull(Object key)

Assert that the key is not null. Throw a JDONullIdentityException if the given key is null.

getTargetClass

public Class getTargetClass()

Return the target class.

Returns:

the target class.

Since:

2.0

getTargetClassName

public String getTargetClassName()

Return the target class name.

Returns:

the target class name.

getKeyAsObject

public Object getKeyAsObject()

Return the key as an Object. The method is synchronized to avoid race conditions in multi-threaded environments.

Returns:

the key as an Object.

createKeyAsObject

protected Object createKeyAsObject()

Create the key as an Object.

Returns:

the key as an Object;

equals

public boolean equals(Object obj)

Check the class and class name and object type. If restored from serialization, class will be null so compare class name.

Overrides:

equals in class Object

Parameters:

obj - the other object

Returns:

true if the class or class name is the same

hashClassName

protected int hashClassName()

Return the hash code of the class name.

Returns:

the hash code of the class name

hashCode

public int hashCode()

Return the cached hash code.

Overrides:

hashCode in class Object

Returns:

the cached hash code.

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Write to the output stream.

Specified by:

writeExternal in interface Externalizable

Parameters:

out - the stream

Throws:

IOException

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Read from the input stream. Creates a new instance with the target class name set.

Specified by:

readExternal in interface Externalizable

Parameters:

in - Input

Throws:

IOException

ClassNotFoundException