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• 0.1.0
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• CassandraMetadataHelper.java

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com.stratio.connector.cassandra.utils.CassandraMetadataHelper Maven / Gradle / Ivy

/*
 * Licensed to STRATIO (C) under one or more contributor license agreements.
 * See the NOTICE file distributed with this work for additional information
 * regarding copyright ownership.  The STRATIO (C) licenses this file
 * to you 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 com.stratio.connector.cassandra.utils;

import java.util.HashMap;
import java.util.Map;

import org.apache.log4j.Logger;

import com.datastax.driver.core.DataType;
import com.stratio.crossdata.common.metadata.ColumnType;

/**
 * Cassandra mapping of META column types to their underlying Java
 * class implementations. The following conversions are considered:
 * 
 * 
 * 
 * BOOLEAN
 * NATIVE
 * 
 * 
 * 
 * 
 * 
 * 
 * 
Cassandra Type
Cassandra Java class
META Column Type
BIGINT
Long
BIGINT
BOOLEAN
Boolean
COUNTER
Long
DOUBLE
Double
DOUBLE
FLOAT
Float
FLOAT
INT
Integer
INT
TEXT
String
TEXT
VARCHAR
String
VARCHAR
TEXT
String
TEXT
 */
public class CassandraMetadataHelper {

    /**
     * Class logger.
     */
    private static final Logger LOG = Logger.getLogger(CassandraMetadataHelper.class.getName());
    /**
     * Mapping of native datatypes to SQL types.
     */
    private static Map nativeODBCType = new HashMap<>();
    private static Map dbType = new HashMap<>();
    private static Map> dbClass = new HashMap<>();

    static {

        dbClass.put(ColumnType.BIGINT, Long.class);
        dbClass.put(ColumnType.BOOLEAN, Boolean.class);
        dbClass.put(ColumnType.DOUBLE, Double.class);
        dbClass.put(ColumnType.FLOAT, Float.class);
        dbClass.put(ColumnType.INT, Integer.class);
        dbClass.put(ColumnType.TEXT, String.class);
        dbClass.put(ColumnType.VARCHAR, String.class);

        dbType.put(ColumnType.BIGINT, "BIGINT");
        dbType.put(ColumnType.BOOLEAN, "BOOLEAN");
        dbType.put(ColumnType.DOUBLE, "DOUBLE");
        dbType.put(ColumnType.FLOAT, "FLOAT");
        dbType.put(ColumnType.INT, "INT");
        dbType.put(ColumnType.TEXT, "TEXT");
        dbType.put(ColumnType.VARCHAR, "VARCHAR");

        nativeODBCType.put(DataType.Name.COUNTER, "SQL_INTEGER");

    }

    /**
     * Mapping between Cassandra datatypes and META datatypes.
     */
    private static Map typeMapping = new HashMap<>();

    /**
     * Class constructor.
     */
    public CassandraMetadataHelper() {
        for (Map.Entry entry : dbType.entrySet()) {
            typeMapping.put(entry.getValue(), entry.getKey());
        }
    }

    /**
     * Transform a Cassandra type to Crossdata type.
     * @param dbTypeName The Cassandra column type.
     * @return The Crossdata ColumnType.
     */
    public ColumnType toColumnType(String dbTypeName) {
        ColumnType result = typeMapping.get(dbTypeName.toUpperCase());
        if (result == null) {
            try {
                DataType.Name cassandraType = DataType.Name.valueOf(dbTypeName.toUpperCase());
                result = ColumnType.NATIVE;
                result.setDBMapping(cassandraType.name(), cassandraType.asJavaClass());
                result.setODBCType(nativeODBCType.get(cassandraType));
            } catch (IllegalArgumentException iae) {
                LOG.error("Invalid database type: " + dbTypeName, iae);
                result = null;
            }
        } else {
            result.setDBMapping(dbType.get(result), dbClass.get(result));
        }

        return result;
    }

}