Class Group

All Implemented Interfaces:
Serializable, DataFormat

public abstract class Group extends HObject
Group is an abstract class. Current implementing classes are the H4Group and H5Group. This class includes general information of a group object such as members of a group and common operations on groups.

Members of a group may include other groups, datasets or links.

Version:
1.1 9/4/2007
Author:
Peter X. Cao
See Also:
  • Field Details

    • parent

      protected Group parent
      The parent group where this group is located. The parent of the root group is null.
    • nMembersInFile

      protected int nMembersInFile
      Total number of (Groups and Datasets) of this group in file.
    • CRT_ORDER_TRACKED

      public static final int CRT_ORDER_TRACKED
      See Also:
    • CRT_ORDER_INDEXED

      public static final int CRT_ORDER_INDEXED
      See Also:
  • Constructor Details

    • Group

      public Group(FileFormat theFile, String name, String path, Group parent)
      Constructs an instance of the group with specific name, path and parent group. An HDF data object must have a name. The path is the group path starting from the root. The parent group is the group where this group is located.

      For example, in H5Group(h5file, "grp", "/groups/", pgroup), "grp" is the name of the group, "/groups/" is the group path of the group, and pgroup the group where "grp" is located.

      Parameters:
      theFile - the file which containing the group.
      name - the name of this group, e.g. "grp01".
      path - the full path of this group, e.g. "/groups/".
      parent - the parent of this group.
    • Group

      @Deprecated public Group(FileFormat theFile, String name, String path, Group parent, long[] oid)
      Deprecated.
      Not for public use in the future.
      Using Group(FileFormat, String, String, Group)
  • Method Details

    • clear

      public void clear()
      Clears up member list and other resources in memory for the group. Since the destructor will clear memory space, the function is usually not needed.
    • addToMemberList

      public void addToMemberList(HObject object)
      Adds an object to the member list of this group in memory.

      Parameters:
      object - the HObject (Group or Dataset) to be added to the member list.
    • removeFromMemberList

      public void removeFromMemberList(HObject object)
      Removes an object from the member list of this group in memory.

      Parameters:
      object - the HObject (Group or Dataset) to be removed from the member list.
    • getMemberList

      public List<HObject> getMemberList()
      Returns the list of members of this group. The list is an java.awt.List containing Groups and Datasets.
      Returns:
      the list of members of this group.
    • setName

      public void setName(String newName) throws Exception
      Sets the name of the group.

      setName (String newName) changes the name of the group in memory and file.

      setName() updates the path in memory for all the objects that are under the group with the new name.

      Overrides:
      setName in class HObject
      Parameters:
      newName - The new name of the group.
      Throws:
      Exception
    • getParent

      public final Group getParent()
      Returns the parent group.
    • isRoot

      public final boolean isRoot()
      Checks if it is a root group.
      Returns:
      true if the group is a root group; otherwise, returns false.
    • getNumberOfMembersInFile

      public int getNumberOfMembersInFile()
      Returns the total number of members of this group in file. Current Java application such as HDFView cannot handle files with large numbers of objects (1,000,000 or more objects) due to JVM memory limitation. The max_members is used so that applications such as HDFView will load up to max_members number of objects. If the number of objects in file is larger than max_members, only max_members are loaded in memory.

      getNumberOfMembersInFile() returns the number of objects in this group. The number of objects in memory is obtained by getMemberList().size().

      Returns:
      Total number of members of this group in the file.