Module org.hdfgroup.object

Package hdf.object.h5

Class H5Link

Object

hdf.object.HObject

hdf.object.h5.H5Link

All Implemented Interfaces:

MetaDataContainer, Serializable

public class H5Link
extends HObject
implements MetaDataContainer

An H5Link object represents an existing HDF5 object in file. H5Link object is an HDF5 object that is either a soft or an external link to an object in a file that does not exist. The type of the object is unknown. Once the object being linked to is created, and the type is known, then H5link object will change its type.

Version:

2.7.2 7/6/2010

Author:

Nidhi Gupta

See Also:

• Serialized Form

Field Summary

Fields inherited from class hdf.object.HObject

fileFormat, linkTargetObjName, oid, SEPARATOR

Constructor Summary

Constructors

Constructor	Description
H5Link(FileFormat theFile, String theName, String thePath)	Constructs an HDF5 link with specific name, path, and parent.
H5Link(FileFormat theFile, String theName, String thePath, long[] oid)	Constructs an HDF5 link with specific name, path, parent and oid.

Method Summary

Modifier and Type	Method	Description
void	clear()	Removes all of the elements from metadata list.
void	close(long id)	Closes access to the object.
List<Attribute>	getMetadata()	Retrieves the object's metadata, such as attributes, from the file.
List<Attribute>	getMetadata(int... attrPropList)	Retrieves the object's metadata, such as attributes, from the file.
long[]	getToken()	Get the token for this object.
boolean	hasAttribute()	Check if the object has any attributes attached.
long	open()	Opens an existing object such as a dataset or group for access.
void	removeMetadata(Object info)	Deletes an existing piece of metadata from this object.
void	setName(String newName)	Sets the name of the object.
void	updateMetadata(Object info)	Updates an existing piece of metadata attached to this object.
void	writeMetadata(Object info)	Writes a specific piece of metadata (such as an attribute) into the file.

Methods inherited from class hdf.object.HObject

createFullname, debug, equals, equals, equalsOID, getFID, getFile, getFileFormat, getFullName, getLinkTargetObjName, getName, getOID, getPath, hashCode, setFullname, setLinkTargetObjName, setPath, toString

Methods inherited from class java.lang.Object

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

Constructor Details

H5Link

public H5Link(FileFormat theFile,
 String theName,
 String thePath)

Constructs an HDF5 link with specific name, path, and parent.

Parameters:

theFile - the file which containing the link.

theName - the name of this link, e.g. "link1".

thePath - the full path of this link, e.g. "/groups/".

H5Link

public H5Link(FileFormat theFile,
 String theName,
 String thePath,
 long[] oid)

Constructs an HDF5 link with specific name, path, parent and oid.

Parameters:

theFile - the file which containing the link.

theName - the name of this link, e.g. "link1".

thePath - the full path of this link, e.g. "/groups/".

oid - the oid of this link, e.g. "/groups/".

Method Details

open

public long open()

Description copied from class: HObject

Opens an existing object such as a dataset or group for access. The return value is an object identifier obtained by implementing classes such as H5.H5Dopen(). This function is needed to allow other objects to be able to access the object. For instance, H5File class uses the open() function to obtain object identifier for copyAttributes(long src_id, long dst_id) and other purposes. The open() function should be used in pair with close(long) function.

Specified by:

open in class HObject

Returns:

the object identifier if successful; otherwise returns a negative value.

See Also:

• HObject.close(long)

close

public void close(long id)

Description copied from class: HObject

Closes access to the object. Sub-classes must implement this interface because different data objects have their own ways of how the data resources are closed. For example, H5Group.close() calls the hdf.hdf5lib.H5.H5Gclose() method and closes the group resource specified by the group id.

Specified by:

close in class HObject

Parameters:

id - The object identifier.

getToken

public long[] getToken()

Get the token for this object.

Returns:

true if it has any attributes, false otherwise.

hasAttribute

public boolean hasAttribute()

Check if the object has any attributes attached.

Specified by:

hasAttribute in interface MetaDataContainer

Returns:

true if it has any attributes, false otherwise.

clear

public void clear()

Removes all of the elements from metadata list. The list should be empty after this call returns.

Specified by:

clear in interface MetaDataContainer

getMetadata

public List<Attribute> getMetadata()
                            throws hdf.hdf5lib.exceptions.HDF5Exception

Retrieves the object's metadata, such as attributes, from the file. Metadata, such as attributes, is stored in a List.

Specified by:

getMetadata in interface MetaDataContainer

Returns:

the list of metadata objects.

Throws:

hdf.hdf5lib.exceptions.HDF5Exception - if the metadata can not be retrieved

getMetadata

public List<Attribute> getMetadata(int... attrPropList)
                            throws hdf.hdf5lib.exceptions.HDF5Exception

Retrieves the object's metadata, such as attributes, from the file. Metadata, such as attributes, is stored in a List.

Parameters:

attrPropList - the list of properties to get

Returns:

the list of metadata objects.

Throws:

hdf.hdf5lib.exceptions.HDF5Exception - if the metadata can not be retrieved

writeMetadata

public void writeMetadata(Object info)
                   throws Exception

Writes a specific piece of metadata (such as an attribute) into the file. If an HDF(4&5) attribute exists in the file, this method updates its value. If the attribute does not exist in the file, it creates the attribute in the file and attaches it to the object. It will fail to write a new attribute to the object where an attribute with the same name already exists. To update the value of an existing attribute in the file, one needs to get the instance of the attribute by getMetadata(), change its values, then use writeMetadata() to write the value.

Specified by:

writeMetadata in interface MetaDataContainer

Parameters:

info - the metadata to write.

Throws:

Exception - if the metadata can not be written

removeMetadata

public void removeMetadata(Object info)
                    throws hdf.hdf5lib.exceptions.HDF5Exception

Deletes an existing piece of metadata from this object.

Specified by:

removeMetadata in interface MetaDataContainer

Parameters:

info - the metadata to delete.

Throws:

hdf.hdf5lib.exceptions.HDF5Exception - if the metadata can not be removed

updateMetadata

public void updateMetadata(Object info)
                    throws hdf.hdf5lib.exceptions.HDF5Exception

Updates an existing piece of metadata attached to this object.

Specified by:

updateMetadata in interface MetaDataContainer

Parameters:

info - the metadata to update.

Throws:

hdf.hdf5lib.exceptions.HDF5Exception - if the metadata can not be updated

setName

public void setName(String newName)
             throws Exception

Description copied from class: HObject

Sets the name of the object. setName (String newName) changes the name of the object in the file.

Overrides:

setName in class HObject

Parameters:

newName - The new name of the object.

Throws:

Exception - if name is root or contains separator