com.pixelmed.dicom
Class AttributeTag

java.lang.Object
  com.pixelmed.dicom.AttributeTag

All Implemented Interfaces:

Comparable

public class AttributeTag
extends Object
implements Comparable

An individual DICOM data element (attribute) tag that includes a group and element (each a 16 bit unsigned binary).

Implements Comparable in order to facilitate sorting (e.g. in lists which are indexed by AttributeTag).

Safe to use in hashed collections such as Hashtable and HashMap (i.e. it takes care to implement hashCode() and equals() consistently).

Constructor Summary

AttributeTag(int group, int element)
Construct a DICOM data element (attribute) tag.

AttributeTag(String s)
Construct a DICOM data element (attribute) tag from its string representation.

Method Summary

int	compareTo(Object o) Compare tags based on the numeric order of their group and then element values.
boolean	equals(Object o) Compare tags based on their group and element values.
int	getElement() Get the element value.
int	getGroup() Get the group value.
AttributeTag	getTagWithRepeatingGroupBase() Make a new tag with the same element but with the base group of the repeating group.
int	hashCode() Get a hash value which represents the tag.
boolean	isCurveGroup() Is the tag a member of a curve group ?
boolean	isFileMetaInformationGroup() Is the tag a File Meta Information tag ?
boolean	isGroupLength() Is the tag a group length tag ?
boolean	isOverlayGroup() Is the tag a member of an overlay group ?
boolean	isPrivate() Is the tag a private tag ?
boolean	isPrivateCreator() Is the tag a private creator tag ?
boolean	isRepeatingGroup() Is the tag a member of a repeating group ?
static void	main(String[] arg)
String	toString() Get a human-readable rendering of the tag.
static String	toString(int group, int element) Get a human-readable rendering of the tag.

Methods inherited from class java.lang.Object

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

Constructor Detail

AttributeTag

public AttributeTag(int group,
                    int element)

Construct a DICOM data element (attribute) tag.

Parameters:

group - the 16 bit unsigned binary group

element - the 16 bit unsigned binary element

AttributeTag

public AttributeTag(String s)
             throws DicomException

Construct a DICOM data element (attribute) tag from its string representation.

Parameters:

s - a String of the form returned by toString(), i.e., "(0xgggg,0xeeee)" where gggg and eeee are the zero-padded hexadecimal representations of the group and element respectively

Throws:

DicomException

Method Detail

getGroup

public int getGroup()

Get the group value.

Returns:

the 16 bit unsigned binary group

getElement

public int getElement()

Get the element value.

Returns:

the 16 bit unsigned binary element

isPrivate

public boolean isPrivate()

Is the tag a private tag ?

Private tags are those with odd-numbered groups.

Returns:

true if private

isPrivateCreator

public boolean isPrivateCreator()

Is the tag a private creator tag ?

Private creator tags are those with odd-numbered groups with elements between 0x0001 and 0x00ff.

Returns:

true if private creator

isGroupLength

public boolean isGroupLength()

Is the tag a group length tag ?

Group length tags are those with a zero element number.

Returns:

true if group length

isFileMetaInformationGroup

public boolean isFileMetaInformationGroup()

Is the tag a File Meta Information tag ?

Group length tags are those with a group of 0x0002.

Returns:

true if is File Meta Information tag

isOverlayGroup

public boolean isOverlayGroup()

Is the tag a member of an overlay group ?

Overlay groups are even 6000-601e (overlays).

Returns:

true if overlay group

isCurveGroup

public boolean isCurveGroup()

Is the tag a member of a curve group ?

Curve groups are even 5000-501e (curves) groups.

Returns:

true if curve group

isRepeatingGroup

public boolean isRepeatingGroup()

Is the tag a member of a repeating group ?

Repeating groups are even 6000-601e (overlays) and 5000-501e (curves) groups.

Returns:

true if repeating group

getTagWithRepeatingGroupBase

public AttributeTag getTagWithRepeatingGroupBase()

Make a new tag with the same element but with the base group of the repeating group.

Helps with dictionary lookup of VR, etc.

E.g., any group 6000-601e would be converted to 6000

Returns:

true if repeating group

toString

public String toString()

Get a human-readable rendering of the tag.

This takes the form "(0xgggg,0xeeee)" where gggg and eeee are the zero-padded hexadecimal representations of the group and element respectively.

Overrides:

toString in class Object

Returns:

the string rendering of the tag

toString

public static String toString(int group,
                              int element)

Get a human-readable rendering of the tag.

This takes the form "(0xgggg,0xeeee)" where gggg and eeee are the zero-padded hexadecimal representations of the group and element respectively.

Parameters:

group - the 16 bit unsigned binary group

element - the 16 bit unsigned binary element

Returns:

the string rendering of the tag

compareTo

public int compareTo(Object o)

Compare tags based on the numeric order of their group and then element values.

Specified by:

compareTo in interface Comparable

Parameters:

o - the AttributeTag to compare this AttributeTag against

Returns:

the value 0 if the argument tag is equal to this object; a value less than 0 if this tag is less than the argument tag; and a value greater than 0 if this tag is greater than the argument tag

equals

public boolean equals(Object o)

Compare tags based on their group and element values.

Overrides:

equals in class Object

Parameters:

o - the AttributeTag to compare this AttributeTag against

Returns:

true if the same group and element number

hashCode

public int hashCode()

Get a hash value which represents the tag.

This method is implemented to override java.lang.Object.hashCode() so as to comply with the contract that two tags that return true for equals() will return the same value for hashCode(), which would not be the case unless overridden (i.e. two allocations of a tag with the same group and element would be equal but the default implementation would return different hash values).

Overrides:

hashCode in class Object

Returns:

a hash value representing the tag

main

public static void main(String[] arg)