io.druid.metadata.storage.derby.DerbyConnector.java Source code

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Here is the source code for io.druid.metadata.storage.derby.DerbyConnector.java

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/*
 * Druid - a distributed column store.
 * Copyright 2012 - 2015 Metamarkets Group Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.druid.metadata.storage.derby;

import com.google.common.base.Supplier;
import com.google.inject.Inject;
import com.metamx.common.logger.Logger;
import io.druid.metadata.MetadataStorageConnectorConfig;
import io.druid.metadata.MetadataStorageTablesConfig;
import io.druid.metadata.SQLMetadataConnector;
import org.apache.commons.dbcp2.BasicDataSource;
import org.skife.jdbi.v2.DBI;
import org.skife.jdbi.v2.Handle;

public class DerbyConnector extends SQLMetadataConnector {
    private static final Logger log = new Logger(DerbyConnector.class);
    private static final String SERIAL_TYPE = "BIGINT GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1)";
    private final DBI dbi;

    @Inject
    public DerbyConnector(Supplier<MetadataStorageConnectorConfig> config,
            Supplier<MetadataStorageTablesConfig> dbTables) {
        super(config, dbTables);

        final BasicDataSource datasource = getDatasource();
        datasource.setDriverClassLoader(getClass().getClassLoader());
        datasource.setDriverClassName("org.apache.derby.jdbc.ClientDriver");

        this.dbi = new DBI(datasource);

        log.info("Configured Derby as metadata storage");
    }

    public DerbyConnector(Supplier<MetadataStorageConnectorConfig> config,
            Supplier<MetadataStorageTablesConfig> dbTables, DBI dbi) {
        super(config, dbTables);
        this.dbi = dbi;
    }

    @Override
    public boolean tableExists(Handle handle, String tableName) {
        return !handle.createQuery("select * from SYS.SYSTABLES where tablename = :tableName")
                .bind("tableName", tableName.toUpperCase()).list().isEmpty();
    }

    @Override
    protected String getSerialType() {
        return SERIAL_TYPE;
    }

    @Override
    public DBI getDBI() {
        return dbi;
    }

    @Override
    public String getValidationQuery() {
        return "VALUES 1";
    }
}