com.xylocore.cassandra.query.TableScanQueryBuilder.java Source code

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Here is the source code for com.xylocore.cassandra.query.TableScanQueryBuilder.java

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//
//   Copyright 2013 The Palantir Corporation
//
//   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 com.xylocore.cassandra.query;

import java.util.LinkedHashMap;
import java.util.Map;
import java.util.concurrent.Executor;
import java.util.concurrent.ForkJoinPool;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.Validate;

import com.datastax.driver.core.Session;

/**
 * FILLIN
 * 
 * @author      Eric R. Medley
 */

public class TableScanQueryBuilder<T> {
    //
    // Members
    //

    private Session session;
    private Executor executor;
    private String keyspace;
    private String tableName;
    private Map<String, String> columnsOfInterest;

    //
    // Class implementation
    //

    private TableScanQueryBuilder() {
        session = null;
        keyspace = null;
        tableName = null;
        columnsOfInterest = new LinkedHashMap<>();

        executor(null);
    }

    public static <T> TableScanQueryBuilder<T> builder() {
        return new TableScanQueryBuilder<>();
    }

    /**
     * FILLIN
     * 
     * @param       aSession
     * 
     * @return
     */
    public TableScanQueryBuilder<T> session(Session aSession) {
        Validate.notNull(aSession, "a session must be specified");

        session = aSession;

        return this;
    }

    /**
     * FILLIN
     * 
     * @param       aKeyspace
     * 
     * @return
     */
    public TableScanQueryBuilder<T> keyspace(String aKeyspace) {
        aKeyspace = StringUtils.trimToNull(aKeyspace);

        keyspace = aKeyspace;

        return this;
    }

    /**
     * FILLIN
     * 
     * @param       aTableName
     * 
     * @return
     */
    public TableScanQueryBuilder<T> tableName(String aTableName) {
        Validate.notBlank(aTableName);

        tableName = aTableName;

        return this;
    }

    /**
     * FILLIN
     * 
     * @param       aExecutor
     * 
     * @return
     */
    public TableScanQueryBuilder<T> executor(Executor aExecutor) {
        if (aExecutor == null) {
            aExecutor = ForkJoinPool.commonPool();
        }

        executor = aExecutor;

        return this;
    }

    /**
     * FILLIN
     * 
     * @param       aColumnNames
     * 
     * @return
     */
    public TableScanQueryBuilder<T> columns(String... aColumnNames) {
        for (int i = 0, ci = aColumnNames.length; i < ci; i++) {
            column(aColumnNames[i]);
        }

        return this;
    }

    /**
     * FILLIN
     * 
     * @param       aColumnName
     * 
     * @return
     */
    public TableScanQueryBuilder<T> column(String aColumnName) {
        return column(aColumnName, null);
    }

    /**
     * FILLIN
     * 
     * @param       aColumnName
     * @param       aAlias
     * 
     * @return
     */
    public TableScanQueryBuilder<T> column(String aColumnName, String aAlias) {
        Validate.notBlank(aColumnName);

        aAlias = StringUtils.trimToNull(aAlias);

        if (aAlias == null) {
            aAlias = aColumnName;
        }

        columnsOfInterest.put(aColumnName, aAlias);

        return this;
    }

    /**
     * FILLIN
     * 
     * @return
     */
    public TableScanQuery<T> build() {
        if (session == null) {
            throw new IllegalStateException("a session has not been specified for the builder");
        }

        if (tableName == null) {
            throw new IllegalStateException("a table name has not been specified for the builder");
        }

        if (columnsOfInterest.isEmpty()) {
            throw new IllegalStateException("at least one column of interest must be specified");
        }

        if (keyspace == null) {
            keyspace = session.getLoggedKeyspace();
        }

        return new TableScanQuery<>(session, executor, keyspace, tableName, columnsOfInterest);
    }
}