Package com.db4o.internal

Class Null

java.lang.Object

com.db4o.internal.Null

All Implemented Interfaces:

PreparedComparison, Comparable4, Indexable4, LinkLengthAware

public class Null
extends java.lang.Object
implements Indexable4, PreparedComparison

Field Summary

Fields

Modifier and Type	Field	Description
static Null	INSTANCE

Method Summary

Modifier and Type	Method	Description
int	compareTo(java.lang.Object a_obj)	return a negative int, zero or a positive int if the object being held in 'this' is smaller, equal or greater than the passed object. Typical implementation: return this.object - obj;
void	defragIndexEntry(DefragmentContextImpl context)
int	linkLength()
PreparedComparison	prepareComparison(Context context, java.lang.Object obj_)	creates a prepared comparison to compare multiple objects against one single object.
java.lang.Object	readIndexEntry(Context context, ByteArrayBuffer a_reader)
void	writeIndexEntry(Context context, ByteArrayBuffer a_writer, java.lang.Object a_object)

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final Null INSTANCE

Method Detail

compareTo

public int compareTo(java.lang.Object a_obj)

Description copied from interface: PreparedComparison

return a negative int, zero or a positive int if the object being held in 'this' is smaller, equal or greater than the passed object.

Typical implementation: return this.object - obj;

Specified by:

compareTo in interface PreparedComparison

linkLength

public int linkLength()

Specified by:

linkLength in interface LinkLengthAware

readIndexEntry

public java.lang.Object readIndexEntry(Context context,
                                       ByteArrayBuffer a_reader)

Specified by:

readIndexEntry in interface Indexable4

writeIndexEntry

public void writeIndexEntry(Context context,
                            ByteArrayBuffer a_writer,
                            java.lang.Object a_object)

Specified by:

writeIndexEntry in interface Indexable4

defragIndexEntry

public void defragIndexEntry(DefragmentContextImpl context)

Specified by:

defragIndexEntry in interface Indexable4

prepareComparison

public PreparedComparison prepareComparison(Context context,
                                            java.lang.Object obj_)

Description copied from interface: Comparable4

creates a prepared comparison to compare multiple objects against one single object.

Specified by:

prepareComparison in interface Comparable4

Parameters:

context - the context of the comparison

obj_ - the object that is to be compared against multiple other objects

Returns:

the prepared comparison