functionsubstr.java

来自「High performance DB query」· Java 代码 · 共 63 行

/*
 * @(#)$Id: FunctionSubstr.java,v 1.5 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;

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

    /**
     * Method evaluate
     *
     * @param parameters
     * @return
     */
    public Object evaluate(Object[] parameters) {
        String outStr = null;
        int params = parameters.length;

        if (params > 0) {
            outStr = parameters[0].toString();
        }

        if (params == 2) {
            return outStr.substring(((Integer) parameters[1]).intValue());
        }

        if (params == 3) {
            return outStr.substring(((Integer) parameters[1]).intValue(),
                                    ((Integer) parameters[2]).intValue());
        }

        return outStr;
    }

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