/** * The contents of this file are subject to the license and copyright * detailed in the LICENSE and NOTICE files at the root of the source * tree and available online at * * http://www.dspace.org/license/ */ package org.dspace.browse; import java.sql.PreparedStatement; import java.sql.SQLException; import java.util.ArrayList; import java.util.Collections; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set; import org.apache.log4j.Logger; import org.dspace.core.Context; import org.dspace.core.ConfigurationManager; import org.dspace.storage.rdbms.DatabaseManager; import org.dspace.storage.rdbms.TableRow; import org.dspace.storage.rdbms.TableRowIterator; /** * This class implements the BrowseCreateDAO interface for the PostgreSQL database * as associated with the default DSpace installation. This class should not * be instantiated directly, but should be obtained via the BrowseDAOFactory: * * <code> * Context context = new Context(); * BrowseCreateDAO dao = BrowseDAOFactory.getCreateInstance(context); * </code> * * This class will then be loaded if the appropriate configuration is made. * * @author Richard Jones * @author Graham Triggs */ public class BrowseCreateDAOPostgres implements BrowseCreateDAO { /** Log4j logger */ private static Logger log = Logger.getLogger(BrowseCreateDAOPostgres.class); /** internal copy of the current DSpace context (including the database connection) */ private Context context; /** Database specific set of utils used when prepping the database */ private BrowseDAOUtils utils; /** * Required constructor for classes implementing the BrowseCreateDAO interface. * Takes a DSpace context to use to connect to the database with. * * @param context the DSpace context */ public BrowseCreateDAOPostgres(Context context) throws BrowseException { this.context = context; // obtain the relevant Utils for this class utils = BrowseDAOFactory.getUtils(context); } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#createCollectionView(java.lang.String, java.lang.String, boolean) */ public String createCollectionView(String table, String view, boolean execute) throws BrowseException { try { String createColView = "CREATE VIEW " + view + " as " + "SELECT Collection2Item.collection_id, " + table + ".* " + "FROM " + table + ", Collection2Item " + "WHERE " + table + ".item_id = Collection2Item.item_id;"; if (execute) { DatabaseManager.updateQuery(context, createColView); } return createColView; } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#createCommunityView(java.lang.String, java.lang.String, boolean) */ public String createCommunityView(String table, String view, boolean execute) throws BrowseException { try { String createComView = "CREATE VIEW " + view + " as " + "SELECT Communities2Item.community_id, " + table + ".* " + "FROM " + table + ", Communities2Item " + "WHERE " + table + ".item_id = Communities2Item.item_id;"; if (execute) { DatabaseManager.updateQuery(context, createComView); } return createComView; } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#createDatabaseIndices(java.lang.String, boolean) */ public String[] createDatabaseIndices(String table, List<Integer> sortCols, boolean value, boolean execute) throws BrowseException { try { ArrayList<String> array = new ArrayList<String>(); array.add("CREATE INDEX " + table + "_item_id_idx ON " + table + "(item_id);"); if (value) { array.add("CREATE INDEX " + table + "_value_idx ON " + table + "(sort_value);"); } for (Integer i : sortCols) { array.add("CREATE INDEX " + table + "_s" + i + "_idx ON " + table + "(sort_" + i + ");"); } if (execute) { for (String query : array) { DatabaseManager.updateQuery(context, query); } } String[] arr = new String[array.size()]; return array.toArray(arr); } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#createDatabaseIndices(java.lang.String, boolean) */ public String[] createMapIndices(String disTable, String mapTable, boolean execute) throws BrowseException { try { String[] arr = new String[5]; arr[0] = "CREATE INDEX " + disTable + "_svalue_idx ON " + disTable + "(sort_value)"; arr[1] = "CREATE INDEX " + disTable + "_value_idx ON " + disTable + "(value)"; arr[2] = "CREATE INDEX " + disTable + "_uvalue_idx ON " + disTable + "(UPPER(value))"; arr[3] = "CREATE INDEX " + mapTable + "_item_id_idx ON " + mapTable + "(item_id)"; arr[4] = "CREATE INDEX " + mapTable + "_dist_idx ON " + mapTable + "(distinct_id)"; if (execute) { for (String query : arr) { DatabaseManager.updateQuery(context, query); } } return arr; } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#createDistinctMap(java.lang.String, java.lang.String, boolean) */ public String createDistinctMap(String table, String map, boolean execute) throws BrowseException { try { String create = "CREATE TABLE " + map + " (" + "map_id integer primary key, " + "item_id integer references item(item_id), " + "distinct_id integer references " + table + "(id)" + ");"; if (execute) { DatabaseManager.updateQuery(context, create); } return create; } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#updateDistinctMapping(java.lang.String, int, int) */ public MappingResults updateDistinctMappings(String table, int itemID, Set<Integer> distinctIDs) throws BrowseException { BrowseMappingResults results = new BrowseMappingResults(); try { Set<Integer> addDistinctIDs = null; // Find all existing mappings for this item TableRowIterator tri = DatabaseManager.queryTable(context, table, "SELECT * FROM " + table + " WHERE item_id=?", itemID); if (tri != null) { addDistinctIDs = (Set<Integer>)((HashSet<Integer>)distinctIDs).clone(); try { while (tri.hasNext()) { TableRow tr = tri.next(); // Check the item mappings to see if it contains this mapping boolean itemIsMapped = false; int trDistinctID = tr.getIntColumn("distinct_id"); if (distinctIDs.contains(trDistinctID)) { // Found this mapping results.addRetainedDistinctId(trDistinctID); // Flag it, and remove (-1) from the item mappings itemIsMapped = true; addDistinctIDs.remove(trDistinctID); } // The item is no longer mapped to this community, so remove the database record if (!itemIsMapped) { results.addRemovedDistinctId(trDistinctID); DatabaseManager.delete(context, tr); } } } finally { tri.close(); } } else { addDistinctIDs = distinctIDs; } // Any remaining mappings need to be added to the database for (int distinctID : addDistinctIDs) { if (distinctID > -1) { TableRow row = DatabaseManager.row(table); row.setColumn("item_id", itemID); row.setColumn("distinct_id", distinctID); DatabaseManager.insert(context, row); results.addAddedDistinctId(distinctID); } } } catch (SQLException e) { log.error("caught exception: ", e); String msg = "problem updating distinct mappings: table=" + table + ",item-id=" + itemID; throw new BrowseException(msg, e); } return results; } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#createDistinctTable(java.lang.String, boolean) */ public String createDistinctTable(String table, boolean execute) throws BrowseException { try { String create = "CREATE TABLE " + table + " (" + "id integer primary key, " + "authority VARCHAR(100), " + "value " + getValueColumnDefinition() + ", " + "sort_value " + getSortColumnDefinition() + ");"; if (execute) { DatabaseManager.updateQuery(context, create); } return create; } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#createPrimaryTable(java.lang.String, java.util.List, boolean) */ public String createPrimaryTable(String table, List<Integer> sortCols, boolean execute) throws BrowseException { try { StringBuffer sb = new StringBuffer(); Iterator itr = sortCols.iterator(); while (itr.hasNext()) { Integer no = (Integer) itr.next(); sb.append(", sort_"); sb.append(no.toString()); sb.append(getSortColumnDefinition()); } String createTable = "CREATE TABLE " + table + " (" + "id integer primary key," + "item_id integer references item(item_id)" + sb.toString() + ");"; if (execute) { DatabaseManager.updateQuery(context, createTable); } return createTable; } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#createSequence(java.lang.String, boolean) */ public String createSequence(String sequence, boolean execute) throws BrowseException { try { String create = "CREATE SEQUENCE " + sequence + ";"; if (execute) { DatabaseManager.updateQuery(context, create); } return create; } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#deleteByItemID(java.lang.String, int) */ public void deleteByItemID(String table, int itemID) throws BrowseException { try { Object[] params = { Integer.valueOf(itemID) }; String dquery = "DELETE FROM " + table + " WHERE item_id = ?"; DatabaseManager.updateQuery(context, dquery, params); } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#deleteCommunityMappings(java.lang.String, int) */ public void deleteCommunityMappings(int itemID) throws BrowseException { try { Object[] params = { Integer.valueOf(itemID) }; String dquery = "DELETE FROM Communities2Item WHERE item_id = ?"; DatabaseManager.updateQuery(context, dquery, params); } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#dropIndexAndRelated(java.lang.String, boolean) */ public String dropIndexAndRelated(String table, boolean execute) throws BrowseException { try { String dropper = "DROP TABLE " + table + " CASCADE;"; if (execute) { DatabaseManager.updateQuery(context, dropper); } return dropper; } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#dropSequence(java.lang.String, boolean) */ public String dropSequence(String sequence, boolean execute) throws BrowseException { try { String dropSeq = "DROP SEQUENCE " + sequence + ";"; if (execute) { DatabaseManager.updateQuery(context, dropSeq); } return dropSeq; } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#dropView(java.lang.String, boolean) */ public String dropView(String view, boolean execute) throws BrowseException { /* Postgres VIEWs are dropped along with the main index if (view != null && !"".equals(view)) { try { String dropView = "DROP VIEW " + view + " CASCADE;"; if (execute) { DatabaseManager.updateQuery(context, dropView); } return dropView; } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } */ return ""; } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#getDistinctID(java.lang.String, java.lang.String, java.lang.String) */ public int getDistinctID(String table, String value, String authority, String sortValue) throws BrowseException { TableRowIterator tri = null; if (log.isDebugEnabled()) { log.debug("getDistinctID: table=" + table + ",value=" + value + ",sortValue=" + sortValue); } try { Object[] params; String select; if (authority != null) { params = new Object[]{ value, authority }; } else { params = new Object[]{ value }; } if (ConfigurationManager.getBooleanProperty("webui.browse.metadata.case-insensitive", false)) { if (authority != null) { select = "SELECT id FROM " + table + " WHERE UPPER(value) = UPPER(?) and authority = ?"; } else { select = "SELECT id FROM " + table + " WHERE UPPER(value) = UPPER(?) and authority IS NULL"; } } else { if (authority != null) { select = "SELECT id FROM " + table + " WHERE value = ? and authority = ?"; } else { select = "SELECT id FROM " + table + " WHERE value = ? and authority IS NULL"; } } tri = DatabaseManager.query(context, select, params); int distinctID = -1; if (!tri.hasNext()) { distinctID = insertDistinctRecord(table, value, authority, sortValue); } else { distinctID = tri.next().getIntColumn("id"); } if (log.isDebugEnabled()) { log.debug("getDistinctID: return=" + distinctID); } return distinctID; } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } finally { if (tri != null) { tri.close(); } } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#updateCommunityMappings(int) */ public void updateCommunityMappings(int itemID) throws BrowseException { try { // Get all the communities for this item int[] commID = getAllCommunityIDs(itemID); // Remove (set to -1) any duplicate communities for (int i = 0; i < commID.length; i++) { if (!isFirstOccurrence(commID, i)) { commID[i] = -1; } } // Find all existing mappings for this item TableRowIterator tri = DatabaseManager.queryTable(context, "Communities2Item", "SELECT * FROM Communities2Item WHERE item_id=?", itemID); if (tri != null) { try { while (tri.hasNext()) { TableRow tr = tri.next(); // Check the item mappings to see if it contains this community mapping boolean itemIsMapped = false; int trCommID = tr.getIntColumn("community_id"); for (int i = 0; i < commID.length; i++) { // Found this community if (commID[i] == trCommID) { // Flag it, and remove (-1) from the item mappings itemIsMapped = true; commID[i] = -1; } } // The item is no longer mapped to this community, so remove the database record if (!itemIsMapped) { DatabaseManager.delete(context, tr); } } } finally { tri.close(); } } // Any remaining mappings need to be added to the database for (int i = 0; i < commID.length; i++) { if (commID[i] > -1) { TableRow row = DatabaseManager.row("Communities2Item"); row.setColumn("item_id", itemID); row.setColumn("community_id", commID[i]); DatabaseManager.insert(context, row); } } } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#insertDistinctRecord(java.lang.String, java.lang.String, java.lang.String) */ public int insertDistinctRecord(String table, String value, String authority, String sortValue) throws BrowseException { log.debug("insertDistinctRecord: table=" + table + ",value=" + value+ ",authority=" + authority+",sortValue=" + sortValue); try { TableRow dr = DatabaseManager.row(table); if (authority != null) { dr.setColumn("authority", utils.truncateValue(authority,100)); } dr.setColumn("value", utils.truncateValue(value)); dr.setColumn("sort_value", utils.truncateSortValue(sortValue)); DatabaseManager.insert(context, dr); int distinctID = dr.getIntColumn("id"); log.debug("insertDistinctRecord: return=" + distinctID); return distinctID; } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#insertIndex(java.lang.String, int, java.lang.String, java.lang.String, java.util.Map) */ public void insertIndex(String table, int itemID, Map<Integer, String> sortCols) throws BrowseException { try { // create us a row in the index TableRow row = DatabaseManager.row(table); // set the primary information for the index row.setColumn("item_id", itemID); // now set the columns for the other sort values for (Map.Entry<Integer, String> sortCol : sortCols.entrySet()) { row.setColumn("sort_" + sortCol.getKey().toString(), utils.truncateSortValue(sortCol.getValue())); } DatabaseManager.insert(context, row); } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#updateIndex(java.lang.String, int, java.util.Map) */ public boolean updateIndex(String table, int itemID, Map<Integer, String> sortCols) throws BrowseException { try { boolean rowUpdated = false; TableRow row = DatabaseManager.findByUnique(context, table, "item_id", itemID); // If the item does not exist in the table, return that it couldn't be found if (row == null) { return false; } // Iterate through all the sort values for (Map.Entry<Integer, String> sortCol : sortCols.entrySet()) { // Generate the appropriate column name String column = "sort_" + sortCol.getKey().toString(); // Create the value that will be written in to the column String newValue = utils.truncateSortValue( sortCol.getValue() ); // Check the column exists - if it doesn't, something has gone seriously wrong if (!row.hasColumn(column)) { throw new BrowseException("Column '" + column + "' does not exist in table " + table); } // Get the existing value from the column String oldValue = row.getStringColumn(column); // If the new value differs from the old value, update the column and flag that the row has changed if (oldValue != null && !oldValue.equals(newValue)) { row.setColumn(column, newValue); rowUpdated = true; } else if (newValue != null && !newValue.equals(oldValue)) { row.setColumn(column, newValue); rowUpdated = true; } } // We've updated the row, so save it back to the database if (rowUpdated) { DatabaseManager.update(context, row); } } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } // Return that the original record was found return true; } public List<Integer> deleteMappingsByItemID(String mapTable, int itemID) throws BrowseException { List<Integer> distinctIds = new ArrayList<Integer>(); TableRowIterator tri = null; try { tri = DatabaseManager.queryTable(context, mapTable, "SELECT * FROM " + mapTable + " WHERE item_id=?", itemID); if (tri != null) { while (tri.hasNext()) { TableRow tr = tri.next(); distinctIds.add(tr.getIntColumn("distinct_id")); DatabaseManager.delete(context, tr); } } } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } finally { if (tri != null) { tri.close(); } } return distinctIds; } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#pruneDistinct(java.lang.String, java.lang.String) */ public void pruneDistinct(String table, String map, List<Integer> distinctIds) throws BrowseException { try { StringBuilder query = new StringBuilder(); query.append("DELETE FROM ").append(table).append(" WHERE NOT EXISTS (SELECT 1 FROM "); query.append(map).append(" WHERE ").append(map).append(".distinct_id = ").append(table).append(".id)"); if (distinctIds != null && distinctIds.size() > 0) { query.append(" AND ").append(table).append(".id=?"); PreparedStatement stmt = null; try { stmt = context.getDBConnection().prepareStatement(query.toString()); for (Integer distinctId : distinctIds) { stmt.setInt(1, distinctId); stmt.execute(); stmt.clearParameters(); } } finally { if (stmt != null) { stmt.close(); } } } else { DatabaseManager.updateQuery(context, query.toString()); } } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#pruneExcess(java.lang.String, boolean) */ public void pruneExcess(String table, boolean withdrawn) throws BrowseException { try { StringBuilder query = new StringBuilder(); query.append("DELETE FROM ").append(table).append(" WHERE NOT EXISTS (SELECT 1 FROM item WHERE item.item_id="); query.append(table).append(".item_id AND "); if (withdrawn) { query.append("item.withdrawn = true"); } else { query.append("item.in_archive = true AND item.withdrawn = false"); } query.append(")"); DatabaseManager.updateQuery(context, query.toString()); } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } try { String itemCriteria = withdrawn ? "item.withdrawn = true" : "item.in_archive = true AND item.withdrawn = false"; String delete = "DELETE FROM " + table + " WHERE NOT EXISTS (SELECT 1 FROM item WHERE item.item_id=" + table + ".item_id AND " + itemCriteria + ")"; DatabaseManager.updateQuery(context, delete); } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#pruneMapExcess(java.lang.String, boolean) */ public void pruneMapExcess(String map, boolean withdrawn, List<Integer> distinctIds) throws BrowseException { try { StringBuilder query = new StringBuilder(); query.append("DELETE FROM ").append(map).append(" WHERE NOT EXISTS (SELECT 1 FROM item WHERE item.item_id="); query.append(map).append(".item_id AND "); if (withdrawn) { query.append("item.withdrawn = true"); } else { query.append("item.in_archive = true AND item.withdrawn = false"); } query.append(")"); if (distinctIds != null && distinctIds.size() > 0) { query.append(" AND ").append(map).append(".distinct_id=?"); PreparedStatement stmt = null; try { stmt = context.getDBConnection().prepareStatement(query.toString()); for (Integer distinctId : distinctIds) { stmt.setInt(1, distinctId); stmt.execute(); stmt.clearParameters(); } } finally { if (stmt != null) { stmt.close(); } } } else { DatabaseManager.updateQuery(context, query.toString()); } } catch (SQLException e) { log.error("caught exception: ", e); throw new BrowseException(e); } } /* (non-Javadoc) * @see org.dspace.browse.BrowseCreateDAO#testTableExistence(java.lang.String) */ public boolean testTableExistence(String table) throws BrowseException { // this method can kill the db connection, so we start up // our own private context to do it Context c = null; try { c = new Context(); String testQuery = "SELECT * FROM " + table + " LIMIT 1"; DatabaseManager.query(c, testQuery); return true; } catch (SQLException e) { return false; } finally { if (c != null) { c.abort(); } } } /** * Get the definition of the sort_value column - always a VARCHAR2 * (required for ordering) * * @return */ private String getSortColumnDefinition() { int size = utils.getSortColumnMaxChars(); if (size < 1) { return " TEXT "; } return " VARCHAR(" + size + ") "; } /** * Get the definition of the value column - TEXT if the size is greater than 4000 bytes * otherwise a VARCHAR2. * * @return */ private String getValueColumnDefinition() { int size = utils.getValueColumnMaxChars(); if (size < 1) { return " TEXT "; } return " VARCHAR(" + size + ") "; } /** * perform a database query to get all the communities that this item belongs to, * including all mapped communities, and ancestors * * this is done here instead of using the Item api, because for reindexing we may * not have Item objects, and in any case this is *much* faster * * @param itemId * @return * @throws SQLException */ private int[] getAllCommunityIDs(int itemId) throws SQLException { List<Integer> commIdList = new ArrayList<Integer>(); TableRowIterator tri = null; try { tri = DatabaseManager.queryTable(context, "Community2Item", "SELECT * FROM Community2Item WHERE item_id=?", itemId); while (tri.hasNext()) { TableRow row = tri.next(); int commId = row.getIntColumn("community_id"); commIdList.add(commId); // Get the parent community, and continue to get all ancestors Integer parentId = getParentCommunityID(commId); while (parentId != null) { commIdList.add(parentId); parentId = getParentCommunityID(parentId); } } } finally { if (tri != null) { tri.close(); } } // Need to iterate the array as toArray will produce an array Integers, // not ints as we need. int[] cIds = new int[commIdList.size()]; for (int i = 0; i < commIdList.size(); i++) { cIds[i] = commIdList.get(i); } return cIds; } /** * Get the id of the parent community. Returns Integer, as null is used to * signify that there are no parents (ie. top-level). * * @param commId * @return * @throws SQLException */ private Integer getParentCommunityID(int commId) throws SQLException { TableRowIterator tri = null; try { tri = DatabaseManager.queryTable(context, "Community2Community", "SELECT * FROM Community2Community WHERE child_comm_id=?", commId); if (tri.hasNext()) { return tri.next().getIntColumn("parent_comm_id"); } } finally { if (tri != null) { tri.close(); } } return null; } /** * Check to see if the integer at pos is the first occurrence of that value * in the array. * * @param ids * @param pos * @return */ private boolean isFirstOccurrence(int[] ids, int pos) { if (pos < 0 || pos >= ids.length) { return false; } int id = ids[pos]; for (int i = 0; i < pos; i++) { if (id == ids[i]) { return false; } } return true; } private static class BrowseMappingResults implements MappingResults { private List<Integer> addedDistinctIds = new ArrayList<Integer>(); private List<Integer> retainedDistinctIds = new ArrayList<Integer>(); private List<Integer> removedDistinctIds = new ArrayList<Integer>(); private void addAddedDistinctId(int id) { addedDistinctIds.add(id); } private void addRetainedDistinctId(int id) { retainedDistinctIds.add(id); } private void addRemovedDistinctId(int id) { removedDistinctIds.add(id); } public List<Integer> getAddedDistinctIds() { return addedDistinctIds; } public List<Integer> getRetainedDistinctIds() { return retainedDistinctIds; } public List<Integer> getRemovedDistinctIds() { return Collections.unmodifiableList(removedDistinctIds); } } }