functionstartswith.java

来自「High performance DB query」· Java 代码 · 共 117 行

/*
 * @(#)$Id: FunctionStartswith.java,v 1.2 2004/07/02 23:59:21 huebsch Exp $
 *
 * Copyright (c) 2001-2004 Regents of the University of California.
 * All rights reserved.
 *
 * This file is distributed under the terms in the attached BERKELEY-LICENSE
 * file. If you do not find these files, copies can be found by writing to:
 * Computer Science Division, Database Group, Universite of California,
 * 617 Soda Hall #1776, Berkeley, CA 94720-1776. Attention: Berkeley License
 *
 * Copyright (c) 2003-2004 Intel Corporation. All rights reserved.
 *
 * This file is distributed under the terms in the attached INTEL-LICENSE file.
 * If you do not find these files, copies can be found by writing to:
 * Intel Research Berkeley, 2150 Shattuck Avenue, Suite 1300,
 * Berkeley, CA, 94704.  Attention:  Intel License Inquiry.
 */


package pier.helpers.functions;

import java.math.BigDecimal;
import java.math.BigInteger;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.sql.Date;
import java.sql.Time;
import java.sql.Timestamp;
import pier.data.AbstractDataType;
import util.BitID;

/**
 * Class FunctionSubstr
 *
 */
public class FunctionStartswith implements Function {

    /**
     * Method evaluate
     *
     * @param parameters
     * @return
     */
    public Object evaluate(Object[] parameters) {
        Boolean result = null;
        int params = parameters.length;
        Object tupleValue = null;
        String prefixValue = null;
        int startLocation = 0;

        if (params < 2) {
            return result;
        }

        if (params >= 2) {
            tupleValue = parameters[0];
            prefixValue = parameters[1].toString();
        }

        if (params >= 3) {
            String prefixMask = parameters[3].toString();

            startLocation = Integer.parseInt(prefixMask);
        }

        if (tupleValue instanceof AbstractDataType) {}

        if (tupleValue instanceof Boolean) {}

        if (tupleValue instanceof BigDecimal) {}

        if (tupleValue instanceof BigInteger) {}

        if (tupleValue instanceof Byte) {}

        if (tupleValue instanceof Double) {}

        if (tupleValue instanceof Float) {}

        if (tupleValue instanceof Integer) {}

        if (tupleValue instanceof Long) {}

        if (tupleValue instanceof Short) {}

        if (tupleValue instanceof String) {}

        if (tupleValue instanceof Time) {}

        if (tupleValue instanceof Timestamp) {}

        if (tupleValue instanceof Date) {}

        if (tupleValue instanceof InetAddress) {}

        if (tupleValue instanceof InetSocketAddress) {}

        if (tupleValue instanceof BitID) {}

        if (result == null) {
            return new Boolean(tupleValue.toString().startsWith(prefixValue,
                    startLocation));
        }

        return result;
    }

    /**
     * Method cacheable
     * @return
     */
    public boolean cacheable() {
        return true;
    }
}