org.alfresco.util.DatabaseMetaDataHelper.java Source code

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Here is the source code for org.alfresco.util.DatabaseMetaDataHelper.java

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/*
 * #%L
 * Alfresco Repository
 * %%
 * Copyright (C) 2005 - 2016 Alfresco Software Limited
 * %%
 * This file is part of the Alfresco software. 
 * If the software was purchased under a paid Alfresco license, the terms of 
 * the paid license agreement will prevail.  Otherwise, the software is 
 * provided under the following open source license terms:
 * 
 * Alfresco is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * Alfresco 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 Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
 * #L%
 */
package org.alfresco.util;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.cfg.Configuration;
import org.springframework.orm.hibernate3.LocalSessionFactoryBean;

/**
 * Helper class to collect all of our DatabaseMetaData interpretations in one place.
 * 
 * @author sfrensley
 *
 */
public class DatabaseMetaDataHelper {

    private static Log logger = LogFactory.getLog(DatabaseMetaDataHelper.class);

    private Configuration cfg;

    public void setLocalSessionFactory(LocalSessionFactoryBean localSessionFactory) {
        this.cfg = localSessionFactory.getConfiguration();
    }

    /**
     * Trys to determine the schema name from the DatabaseMetaData obtained from the Connection.
     * @param connection A database connection
     * @return String
     */
    private String getSchemaFromConnection(Connection connection) {

        if (connection == null) {
            logger.error("Unable to determine schema due to null connection.");
            return null;
        }

        ResultSet schemas = null;

        try {
            final DatabaseMetaData dbmd = connection.getMetaData();

            // Assume that if there are schemas, we want the one named after the connection user or the one called "dbo" (MS
            // SQL hack)
            String schema = null;
            schemas = dbmd.getSchemas();
            while (schemas.next()) {
                final String thisSchema = schemas.getString("TABLE_SCHEM");
                if (thisSchema.equals(dbmd.getUserName()) || thisSchema.equalsIgnoreCase("dbo")) {
                    schema = thisSchema;
                    break;
                }
            }
            return schema;
        } catch (Exception e) {
            logger.error("Unable to determine current schema.", e);
        } finally {
            if (schemas != null) {
                try {
                    schemas.close();
                } catch (Exception e) {
                    //noop
                }
            }
        }
        return null;
    }

    public String getSchema(Connection connection) {
        String schema = null;

        if (this.cfg != null) {
            String tmpSchema = this.cfg.getProperty("hibernate.default_schema");
            if (tmpSchema != null && tmpSchema.trim().length() > 0) {
                schema = tmpSchema;
            }
        }

        // if hibernate.default_schema was specified as a system property, then override previous value
        String tmpSchema = System.getProperty("hibernate.default_schema");
        if (tmpSchema != null && tmpSchema.length() > 0) {
            schema = tmpSchema;
        }

        if (schema == null) {
            schema = getSchemaFromConnection(connection);
        }

        return schema;
    }

}