/*

 * Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package sun.tools.jstat;

import java.text.*;

import sun.jvmstat.monitor.MonitorException;

/**

 * A class implementing the Closure interface which is used to resolve

 * all the symbols in the expressions contained in ColumnFormat objects.

 *

 * @author Brian Doherty

 * @since 1.5

 */

public class SymbolResolutionClosure implements Closure {

    private static final boolean debug =

            Boolean.getBoolean("SymbolResolutionClosure.debug");

    private ExpressionEvaluator ee;

    public SymbolResolutionClosure(ExpressionEvaluator ee) {

        this.ee = ee;

    }

    public void visit(Object o, boolean hasNext) throws MonitorException {

        if (! (o instanceof ColumnFormat)) {

            return;

        }

        ColumnFormat c = (ColumnFormat)o;

        Expression e = c.getExpression();

        String previous = e.toString();

        e = (Expression)ee.evaluate(e);

        if (debug) {

            System.out.print("Expression: " + previous + " resolved to "

                             + e.toString());

        }

        c.setExpression(e);

    }

}