hdf5/java/examples/groups/H5Ex_G_Visit.java

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://www.hdfgroup.org/licenses.               *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/************************************************************
 This example shows how to recursively traverse a file
 using H5Ovisit and H5Lvisit.  The program prints all of
 the objects in the file specified in FILE, then prints all
 of the links in that file.  The default file used by this
 example implements the structure described in the User's
 Guide, chapter 4, figure 26.
 ************************************************************/
package examples.groups;

import hdf.hdf5lib.H5;
import hdf.hdf5lib.HDF5Constants;
import hdf.hdf5lib.callbacks.H5L_iterate_t;
import hdf.hdf5lib.callbacks.H5L_iterate_opdata_t;
import hdf.hdf5lib.callbacks.H5O_iterate_t;
import hdf.hdf5lib.callbacks.H5O_iterate_opdata_t;
import hdf.hdf5lib.structs.H5L_info_t;
import hdf.hdf5lib.structs.H5O_info_t;

import java.util.ArrayList;

public class H5Ex_G_Visit {

    private static String FILE = "groups/h5ex_g_visit.h5";

    public static void main(String[] args) {
        try {
            (new H5Ex_G_Visit()).VisitGroup();
        }
        catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    private void VisitGroup() throws Exception {

        long file_id = HDF5Constants.H5I_INVALID_HID;

        try {
            // Open file
            file_id = H5.H5Fopen(FILE, HDF5Constants.H5F_ACC_RDONLY, HDF5Constants.H5P_DEFAULT);

            // Begin iteration using H5Ovisit
            System.out.println("Objects in the file:");
            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);
            System.out.println();
            // Repeat the same process using H5Lvisit
            H5L_iterate_opdata_t iter_data2 = new H5L_iter_data();
            H5L_iterate_t iter_cb2 = new H5L_iter_callback();
            System.out.println("Links in the file:");
            H5.H5Lvisit(file_id, HDF5Constants.H5_INDEX_NAME, HDF5Constants.H5_ITER_NATIVE, iter_cb2, iter_data2);

        }
        catch (Exception e) {
            e.printStackTrace();
        }
        finally {
            // Close and release resources.
            if (file_id >= 0)
                H5.H5Fclose(file_id);
        }
    }

    /************************************************************
     * Operator function for H5Lvisit. This function simply retrieves the info for the object the current link points
     * to, and calls the operator function for H5Ovisit.
     ************************************************************/

    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 H5L_iter_data implements H5L_iterate_opdata_t {
        public ArrayList<idata> iterdata = new ArrayList<idata>();
    }

    private class H5L_iter_callback implements H5L_iterate_t {
        public int callback(long group, String name, H5L_info_t info, H5L_iterate_opdata_t op_data) {

            idata id = new idata(name, info.type);
            ((H5L_iter_data) op_data).iterdata.add(id);

            H5O_info_t infobuf;
            int ret = 0;
            try {
                // Get type of the object and display its name and type. The name of the object is passed to this
                // function by the Library.
                infobuf = H5.H5Oget_info_by_name(group, name, HDF5Constants.H5P_DEFAULT);
                H5O_iterate_t iter_cbO = new H5O_iter_callback();
                H5O_iterate_opdata_t iter_dataO = new H5O_iter_data();
                ret = iter_cbO.callback(group, name, infobuf, iter_dataO);
            }
            catch (Exception e) {
                e.printStackTrace();
            }

            return ret;
        }
    }

    private class H5O_iter_data implements H5O_iterate_opdata_t {
        public ArrayList<idata> iterdata = new ArrayList<idata>();
    }

    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;
        }
    }

}