Class HObject
- All Implemented Interfaces:
Serializable
,DataFormat
HObject __________________________|________________________________ | | | Group Dataset Datatype | _________|___________ | | | | | | ScalarDS CompoundDS | | | | | ---------------------Implementing classes such as------------------------- ____|____ _____|______ _____|_____ _____|_____ | | | | | | | | H5Group H4Group H5ScalarDS H4SclarDS H5CompDS H4CompDS H5Datatype H4DatatypeAll HDF4 and HDF5 data objects are inherited from HObject. At the top level of the hierarchy, both HDF4 and HDF5 have the same super-classes, such as Group and Dataset. At the bottom level of the hierarchy, HDF4 and HDF5 objects have their own implementation, such as H5Group, H5ScalarDs, H5CompoundDS, and H5Datatype.
Warning: HDF4 and HDF5 may have multiple links to the same object. Data objects in this model do not deal with multiple links. Users may create duplicate copies of the same data object with different pathes. Applications should check the OID of the data object to avoid duplicate copies of the same object.
HDF4 objects are uniquely identified by the OID of the (ref_id, tag_id) pair. The ref_id is the object reference count. tag_id is a pre-defined number to identify the type of object. For example, DFTAG_RI is for raster image, DFTAG_SD is for scientific dataset, and DFTAG_VG is for Vgroup.
HDF5 objects are uniquely identified by the OID or object reference. The OID is usually obtained by H5Rcreate(). The following example shows how to retrieve an object ID from a file.
// retrieve the object ID try { byte[] ref_buf = H5.H5Rcreate(h5file.getFID(), this.getFullName(), HDF5Constants.H5R_OBJECT, -1); long[] oid = new long[1]; oid[0] = HDFNativeData.byteToLong(ref_buf, 0); } catch (Exception ex) { }
- Version:
- 1.1 9/4/2007
- Author:
- Peter X. Cao
- See Also:
-
Field Summary
FieldsModifier and TypeFieldDescriptionprotected final FileFormat
The file which contains the objectprotected String
The name of the Target Object that is being linked to.protected long[]
Array of long integer storing unique identifier for the object.static final String
The separator of object path, i.e. -
Constructor Summary
ConstructorsConstructorDescriptionHObject()
Constructs an instance of a data object without name and path.HObject
(FileFormat theFile, String theName, String thePath) Constructs an instance of a data object with specific name and path.HObject
(FileFormat theFile, String theName, String thePath, long[] oid) Deprecated. -
Method Summary
Modifier and TypeMethodDescriptionabstract void
close
(int id) Closes access to the object.protected final void
Print out debug informationfinal boolean
equalsOID
(long[] theID) Checks if the OID of the object is the same as the given object identifier within the same file.final int
getFID()
Returns the file identifier of of the file containing the object.final String
getFile()
Returns the name of the file that contains this data object.final FileFormat
Returns the file that contains the object.final String
Returns the full name (group path + object name) of the object.final String
Returns the name of the target object that is linked to.final String
getName()
Returns the name of the object.final long[]
getOID()
Returns a cloned copy of the object identifier.final String
getPath()
Returns the group path of the object.abstract int
open()
Opens an existing object such as dataset or group for access.final void
setLinkTargetObjName
(String targetObjName) Sets the name of the target object that is linked to.void
Sets the name of the object.void
Sets the path of the object.toString()
Returns the name of the object.Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods inherited from interface ncsa.hdf.object.DataFormat
getMetadata, hasAttribute, removeMetadata, updateMetadata, writeMetadata
-
Field Details
-
separator
The separator of object path, i.e. "/".- See Also:
-
fileFormat
The file which contains the object -
oid
protected long[] oidArray of long integer storing unique identifier for the object.HDF4 objects are uniquely identified by a (ref_id, tag_id) pair. i.e. oid[0]=tag, oid[1]=ref.
HDF5 objects are uniquely identified by an object reference. -
linkTargetObjName
The name of the Target Object that is being linked to.
-
-
Constructor Details
-
HObject
public HObject()Constructs an instance of a data object without name and path. -
HObject
Constructs an instance of a data object with specific name and path.For example, in H5ScalarDS(h5file, "dset", "/arrays"), "dset" is the name of the dataset, "/arrays" is the group path of the dataset.
- Parameters:
theFile
- the file that contains the data object.theName
- the name of the data object, e.g. "dset".thePath
- the group path of the data object, e.g. "/arrays".
-
HObject
Deprecated.Not for public use in the future.
UsingHObject(FileFormat, String, String)
-
-
Method Details
-
debug
Print out debug information- Parameters:
msg
- the debug message to print
-
getFile
Returns the name of the file that contains this data object.The file name is necessary because the file of this data object is uniquely identified when multiple files are opened by an application at the same time.
- Specified by:
getFile
in interfaceDataFormat
- Returns:
- The full path (path + name) of the file.
-
getName
Returns the name of the object. For example, "Raster Image #2".- Returns:
- The name of the object.
-
getLinkTargetObjName
Returns the name of the target object that is linked to.- Returns:
- The name of the object that is linked to.
-
setLinkTargetObjName
Sets the name of the target object that is linked to. -
getFullName
Returns the full name (group path + object name) of the object. For example, "/Images/Raster Image #2"- Returns:
- The full name (group path + object name) of the object.
-
getPath
Returns the group path of the object. For example, "/Images".- Returns:
- The group path of the object.
-
setName
Sets the name of the object.setName (String newName) changes the name of the object in the file.
- Parameters:
newName
- The new name of the object.- Throws:
Exception
-
setPath
Sets the path of the object.setPath() is needed to change the path for an object when the name of a group conatining the object is changed by setName(). The path of the object in memory under this group should be updated to the new path to the group. Unlike setName(), setPath() does not change anything in file.
- Parameters:
newPath
- The new path of the object.- Throws:
Exception
-
open
public abstract int open()Opens an existing object such as 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(int src_id, int dst_id) and other purposes. The open() function should be used in pair with close(int) function.- Returns:
- the object identifier if successful; otherwise returns a negative value.
- See Also:
-
close
public abstract void close(int id) 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 ncsa.hdf.hdf5lib.H5.H5Gclose() method and closes the group resource specified by the group id.
- Parameters:
id
- The object identifier.
-
getFID
public final int getFID()Returns the file identifier of of the file containing the object.- Returns:
- the file identifier of of the file containing the object.
-
equalsOID
public final boolean equalsOID(long[] theID) Checks if the OID of the object is the same as the given object identifier within the same file.HDF4 and HDF5 data objects are identified by their unique OIDs. A data object in a file may have multiple logical names , which are represented in a graph structure as separate objects.
The HObject.equalsOID(long[] theID) can be used to check if two data objects with different names are pointed to the same object within the same file.
- Returns:
- true if the ID of the object equals the given OID; otherwise, returns false.
-
getFileFormat
Returns the file that contains the object.- Returns:
- The file that contains the object.
-
getOID
public final long[] getOID()Returns a cloned copy of the object identifier.The object OID cannot be modified once it is created. getIOD() clones the object OID to ensure the object OID cannot be modified outside of this class.
- Returns:
- the cloned copy of the object OID.
-
toString
Returns the name of the object.This method overwrites the toString() method in the Java Object class (the root class of all Java objects) so that it returns the name of the HObject instead of the name of the class.
For example, toString() returns "Raster Image #2" instead of "ncsa.hdf.object.h4.H4SDS".
-
Using
HObject(FileFormat, String, String)