Dépôt officiel du code source de l'ERP OpenConcerto

/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

 *

 * Copyright 2011 OpenConcerto, by ILM Informatique. All rights reserved.

 *

 * The contents of this file are subject to the terms of the GNU General Public License Version 3

 * only ("GPL"). You may not use this file except in compliance with the License. You can obtain a

 * copy of the License at http://www.gnu.org/licenses/gpl-3.0.html See the License for the specific

 * language governing permissions and limitations under the License.

 *

 * When distributing the software, include this License Header Notice in each file.

 */

 package org.openconcerto.sql.model;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

import java.sql.SQLException;

import java.util.HashMap;

import java.util.Map;

/**

 * A class to help find fields by their fullname in resultset. Some jdbc drivers only accept the

 * short name of fields, eg you execute "select B.DESIGNATION from BATIMENT B" but you can only

 * access the designation with "DESIGNATION". With this class you can ask the index of

 * "BATIMENT.DESIGNATION".

 *

 * @author Sylvain

 */

public final class ResultSetFullnameHelper {

    private final ResultSet delegate;

    private ResultSetMetaData rsMD;

    private final Map<String, Map<String, Integer>> tablesMap;

    public ResultSetFullnameHelper(ResultSet rs) {

        this.delegate = rs;

        this.tablesMap = new HashMap<>();

        this.rsMD = null;

    }

    public final ResultSet getRS() {

        return this.delegate;

    }

    private final ResultSetMetaData getMetaData() throws SQLException {

        if (this.rsMD == null) {

            this.rsMD = this.delegate.getMetaData();

        }

        return this.rsMD;

    }

    public final int getIndex(SQLField f) throws SQLException {

        return this.getIndex(f.getTable().getName(), f.getName());

    }

    public final int getIndex(String fieldFullName) throws SQLException {

        final SQLName names = SQLName.parse(fieldFullName);

        return this.getIndex(names.getItem(-2), names.getName());

    }

    /**

     * Get the index of the specified field.

     *

     * @param tableName the table of the field, eg "SITE".

     * @param fieldName the name of the field, eg "DESIGNATION".

     * @return the index of the field, or -1 if not found.

     * @throws SQLException if an error occur while retrieving metadata.

     */

    public final int getIndex(String tableName, String fieldName) throws SQLException {

        final Map<String, Integer> m = this.tablesMap.computeIfAbsent(tableName, (k) -> new HashMap<>());

        if (!m.containsKey(fieldName)) {

            final int index = this.searchIndex(tableName, fieldName);

            m.put(fieldName, index < 1 ? null : new Integer(index));

        }

        final Integer val = m.get(fieldName);

        return val == null ? -1 : val.intValue();

    }

    private final int searchIndex(String tableName, String fieldName) throws SQLException {

        for (int i = 1; i <= this.getMetaData().getColumnCount(); i++) {

            final String colName = this.getMetaData().getColumnName(i);

            if (colName.equals(fieldName) && this.getMetaData().getTableName(i).equals(tableName)) {

                return i;

            }

        }

        return -1;

    }

}