Metacat

import java.util.ArrayList;

import java.util.List;

    /**

     * Get the SystemMetadata for the specified id from the distributed Map.

     * The null maybe is returned if there is no system metadata found.

     * @param id  the specified id.

     * @return the SystemMetadata associated with the id.

     */

    public SystemMetadata getSystemMetadata(String id) {

        SystemMetadata metadata = null;

        if(systemMetadataMap != null && id != null) {

            metadata = systemMetadataMap.get(id);

        }

        return metadata;

    }

    /**

     * Get the obsoletes chain of the specified id. The returned list doesn't include

     * the specified id itself. The newer version has the lower index number in the list.

     * Empty list will be returned if there is no document to be obsoleted by this id.

     * @param id

     * @return

     */

    public List<String> getObsoletes(String id) {

        List<String> obsoletes = new ArrayList<String>();

        while (id != null) {

            SystemMetadata metadata = getSystemMetadata(id);

            id = null;//set it to be null in order to stop the while loop if the id can't be assinged to a new value in the following code.

            if(metadata != null) {

                Identifier identifier = metadata.getObsoletes();

                if(identifier != null && identifier.getValue() != null && !identifier.getValue().trim().equals("")) {

                    obsoletes.add(identifier.getValue());

                    id = identifier.getValue();

                } 

            } 

        }

        return obsoletes;

    }