org.obiba.runtime.upgrade.support.DatabaseMetadataUtil.java Source code

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Here is the source code for org.obiba.runtime.upgrade.support.DatabaseMetadataUtil.java

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/***********************************************************************************************************************
 * Copyright 2008(c) The OBiBa Consortium. All rights reserved.
 *
 * This program and the accompanying materials are made available under the terms of the GNU Public License v3.0.
 *
 * You should have received a copy of the GNU General Public License along with this program. If not, see
 * <http://www.gnu.org/licenses/>.
 **********************************************************************************************************************/
package org.obiba.runtime.upgrade.support;

import java.sql.DatabaseMetaData;
import java.sql.SQLException;

import javax.sql.DataSource;

import org.springframework.jdbc.support.DatabaseMetaDataCallback;
import org.springframework.jdbc.support.JdbcUtils;
import org.springframework.jdbc.support.MetaDataAccessException;

public class DatabaseMetadataUtil {
    //
    // Instance Variables
    //

    private final DataSource dataSource;

    //
    // Constructors
    //

    public DatabaseMetadataUtil(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    //
    // Methods
    //

    /**
     * Returns the database product name.
     *
     * @return database product name
     */
    public String getDatabaseProductName() {
        String databaseProductName;
        try {
            databaseProductName = (String) JdbcUtils.extractDatabaseMetaData(dataSource,
                    new DatabaseMetaDataCallback() {
                        @Override
                        public Object processMetaData(DatabaseMetaData dbmd)
                                throws SQLException, MetaDataAccessException {
                            return dbmd.getDatabaseProductName();
                        }
                    });
        } catch (MetaDataAccessException e) {
            throw new RuntimeException(e);
        }

        return databaseProductName;
    }

    /**
     * Indicates whether the specified table exists.
     *
     * @param tableName the table name
     * @return <code>true</code> if the table exists
     */
    public boolean isTableExists(final String tableName) {
        boolean tablePresent = false;

        try {
            tablePresent = (Boolean) JdbcUtils.extractDatabaseMetaData(dataSource, new DatabaseMetaDataCallback() {
                @Override
                public Object processMetaData(DatabaseMetaData dbmd) throws SQLException, MetaDataAccessException {
                    return dbmd.getTables(null, null, tableName, null).next();
                }
            });
        } catch (MetaDataAccessException ex) {
            throw new RuntimeException(ex);
        }

        return tablePresent;
    }

    /**
     * Indicates whether the specified table contains the specified column.
     *
     * @param tableName the table name
     * @param columnName the column name
     * @return <code>true</code> if the column exists in the table
     */
    public boolean hasColumn(final String tableName, final String columnName) {
        boolean columnPresent = false;

        try {
            columnPresent = (Boolean) JdbcUtils.extractDatabaseMetaData(dataSource, new DatabaseMetaDataCallback() {
                @Override
                public Object processMetaData(DatabaseMetaData dbmd) throws SQLException, MetaDataAccessException {
                    return dbmd.getColumns(null, null, tableName, columnName).next();
                }
            });
        } catch (MetaDataAccessException ex) {
            throw new RuntimeException(ex);
        }

        return columnPresent;
    }
}