H5ObjectEx_G_Intermediate.java

/************************************************************
This example shows how to create intermediate groups with
a single call to H5Gcreate.
 ************************************************************/
package groups;

import java.util.ArrayList;

import hdf.object.FileFormat;
import hdf.object.h5.H5File;

import hdf.hdf5lib.H5;
import hdf.hdf5lib.HDF5Constants;
import hdf.hdf5lib.callbacks.H5O_iterate_opdata_t;
import hdf.hdf5lib.callbacks.H5O_iterate_t;
import hdf.hdf5lib.structs.H5O_info_t;

public class H5ObjectEx_G_Intermediate {

    private static String FILE = "H5ObjectEx_G_Intermediate.h5";

    private void CreateGroup() throws Exception
    {
        H5File file  = null;
        long file_id = -1;
        long lcpl_id = -1;

        try {
            // Create a new file_id using the default properties.
            file    = new H5File(FILE, FileFormat.CREATE);
            file_id = file.open();

            // Create group_id creation property list and set it to allow creation of intermediate group_ids.
            lcpl_id = H5.H5Pcreate(HDF5Constants.H5P_LINK_CREATE);
            H5.H5Pset_create_intermediate_group(lcpl_id, true);

            /*
             * Create the group_id /G1/G2/G3.  Note that /G1 and /G1/G2 do not
             * exist yet.  This call would cause an error if we did not use the
             * previously created property list.
             */
            file.createGroup("/G1/G2/G3", null, lcpl_id);
            // Print all the objects in the file_ids to show that intermediate group_ids have been created.
            System.out.println("Objects in the file_id:");

            // H5O_iterate_opdata_t iter_data = null;
            H5O_iterate_opdata_t iter_data = new H5O_iter_data();
            H5O_iterate_t iter_cb          = new H5O_iter_callback();

            H5.H5Ovisit(file_id, HDF5Constants.H5_INDEX_NAME, HDF5Constants.H5_ITER_NATIVE, iter_cb,
                        iter_data);
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        finally {
            // Close and release resources.
            if (lcpl_id >= 0)
                H5.H5Pclose(lcpl_id);
            file.close();
        }
    }

    public static void main(String[] args)
    {
        try {
            (new H5ObjectEx_G_Intermediate()).CreateGroup();
        }
        catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    private class idata {
        public String link_name = null;
        public int link_type    = -1;
        idata(String name, int type)
        {
            this.link_name = name;
            this.link_type = type;
        }
    }
    private class H5O_iter_data implements H5O_iterate_opdata_t {
        public ArrayList<idata> iterdata = new ArrayList<>();
    }

    private class H5O_iter_callback implements H5O_iterate_t {
        public int callback(long group, String name, H5O_info_t info, H5O_iterate_opdata_t op_data)
        {
            idata id = new idata(name, info.type);
            ((H5O_iter_data)op_data).iterdata.add(id);

            System.out.print("/"); /* Print root group in object path */

            // Check if the current object is the root group, and if not print the full path name and type.

            if (name.charAt(0) == '.') /* Root group, do not print '.' */
                System.out.println("  (Group)");
            else if (info.type == HDF5Constants.H5O_TYPE_GROUP)
                System.out.println(name + "  (Group)");
            else if (info.type == HDF5Constants.H5O_TYPE_DATASET)
                System.out.println(name + "  (Dataset)");
            else if (info.type == HDF5Constants.H5O_TYPE_NAMED_DATATYPE)
                System.out.println(name + "  (Datatype)");
            else
                System.out.println(name + "  (Unknown)");

            return 0;
        }
    }
}