net.solarnetwork.node.dao.jdbc.derby.DerbyCustomFunctionsInitializer.java Source code

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Here is the source code for net.solarnetwork.node.dao.jdbc.derby.DerbyCustomFunctionsInitializer.java

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/* ==================================================================
 * DerbyCustomFunctionsInitializer.java - Nov 15, 2013 3:53:52 PM
 * 
 * Copyright 2007-2013 SolarNetwork.net Dev Team
 * 
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of the GNU General Public License as 
 * published by the Free Software Foundation; either version 2 of 
 * the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, 
 * but WITHOUT ANY WARRANTY; without even the implied warranty of 
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License 
 * along with this program; if not, write to the Free Software 
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 
 * 02111-1307 USA
 * ==================================================================
 */

package net.solarnetwork.node.dao.jdbc.derby;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.ConnectionCallback;
import org.springframework.jdbc.core.JdbcOperations;

/**
 * Register custom functions in the Derby database.
 * 
 * @author matt
 * @version 1.0
 */
public class DerbyCustomFunctionsInitializer {

    private JdbcOperations jdbcOperations;

    private static final String BITWISE_AND = "BITWISE_AND";
    private static final String BITWISE_OR = "BITWISE_OR";

    // Note: I wanted to put this method in DerbyBitwiseFunctions itself, but PDE requires
    // the fragement host to include Eclipse-ExtensibleAPI: true or else the classpath fails
    private static void registerBitwiseFunctions(final Connection con, String schema) throws SQLException {
        DatabaseMetaData dbMeta = con.getMetaData();
        ResultSet rs = dbMeta.getFunctions(null, null, null);
        Set<String> functionNames = new HashSet<String>(Arrays.asList(BITWISE_AND, BITWISE_OR));
        while (rs.next()) {
            String schemaName = rs.getString(2);
            String functionName = rs.getString(3).toUpperCase();
            if (schema.equalsIgnoreCase(schemaName) && functionNames.contains(functionName)) {
                functionNames.remove(functionName);
            }
        }

        // at this point, functionNames contains the functions we need to create
        if (functionNames.size() > 0) {
            final String sqlTemplate = "CREATE FUNCTION %s.%s( parm1 INTEGER, param2 INTEGER ) "
                    + "RETURNS INTEGER LANGUAGE JAVA DETERMINISTIC PARAMETER STYLE JAVA NO SQL "
                    + "EXTERNAL NAME 'net.solarnetwork.node.dao.jdbc.derby.ext.DerbyBitwiseFunctions.%s'";
            if (functionNames.contains(BITWISE_AND)) {
                final String sql = String.format(sqlTemplate, schema, BITWISE_AND, "bitwiseAnd");
                con.createStatement().execute(sql);
            }
            if (functionNames.contains(BITWISE_OR)) {
                final String sql = String.format(sqlTemplate, schema, BITWISE_OR, "bitwiseOr");
                con.createStatement().execute(sql);
            }
        }
    }

    public void init() {
        jdbcOperations.execute(new ConnectionCallback<Object>() {

            @Override
            public Object doInConnection(Connection con) throws SQLException, DataAccessException {
                registerBitwiseFunctions(con, "solarnode");
                return null;
            }
        });
    }

    public void setJdbcOperations(JdbcOperations jdbcOperations) {
        this.jdbcOperations = jdbcOperations;
    }

}