BinaryOpValueExp.java

/*
 * Copyright (c) 1999, 2003, 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 javax.management;


/**
 * This class is used by the query-building mechanism to represent binary
 * operations.
 * @serial include
 *
 * @since 1.5
 */
class BinaryOpValueExp extends QueryEval implements ValueExp { 
    
    /* Serial version */
    private static final long serialVersionUID = 1216286847881456786L;

    /** 
     * @serial The operator 
     */
    private int op;
    
    /** 
     * @serial The first value 
     */
    private ValueExp exp1;

    /** 
     * @serial The second value 
     */
    private ValueExp exp2;


    /**
     * Basic Constructor.
     */
    public BinaryOpValueExp() { 
    } 

    /**
     * Creates a new BinaryOpValueExp using operator o applied on v1 and
     * v2 values.
     */
    public BinaryOpValueExp(int o, ValueExp v1, ValueExp v2) { 
	op   = o;
	exp1 = v1;
	exp2 = v2;
    } 


    /**
     * Returns the operator of the value expression.
     */
    public int getOperator()  { 
	return op;
    } 
    
    /**
     * Returns the left value of the value expression.
     */
    public ValueExp getLeftValue()  { 
	return exp1;
    } 
   
    /**
     * Returns the right value of the value expression.
     */    
    public ValueExp getRightValue()  { 
	return exp2;
    } 

    /**
     * Applies the BinaryOpValueExp on a MBean.
     *
     * @param name The name of the MBean on which the BinaryOpValueExp will be applied.
     *
     * @return  The ValueExp.
     *
     * @exception BadStringOperationException
     * @exception BadBinaryOpValueExpException
     * @exception BadAttributeValueExpException 
     * @exception InvalidApplicationException
     */
    public ValueExp apply(ObjectName name) throws BadStringOperationException, BadBinaryOpValueExpException,
	BadAttributeValueExpException, InvalidApplicationException  { 
	ValueExp val1 = exp1.apply(name);
	ValueExp val2 = exp2.apply(name);
	String sval1;
	String sval2;
	double dval1;
	double dval2;
	long   lval1;
	long   lval2;
	boolean numeric = val1 instanceof NumericValueExp;
	
	if (numeric) {
	    if (((NumericValueExp)val1).isLong()) {
		lval1 = ((NumericValueExp)val1).longValue();
		lval2 = ((NumericValueExp)val2).longValue();

		switch (op) {
		case Query.PLUS:
		    return Query.value(lval1 + lval2);
		case Query.TIMES:
		    return Query.value(lval1 * lval2);
		case Query.MINUS:
		    return Query.value(lval1 - lval2);
		case Query.DIV:
		    return Query.value(lval1 / lval2);
		}
		
	    } else {
		dval1 = ((NumericValueExp)val1).doubleValue();
		dval2 = ((NumericValueExp)val2).doubleValue();

		switch (op) {
		case Query.PLUS:
		    return Query.value(dval1 + dval2);
		case Query.TIMES:
		    return Query.value(dval1 * dval2);
		case Query.MINUS:
		    return Query.value(dval1 - dval2);
		case Query.DIV:
		    return Query.value(dval1 / dval2);
		}
	    }
	} else {
	    sval1 = ((StringValueExp)val1).getValue();
	    sval2 = ((StringValueExp)val2).getValue();

	    switch (op) {
	    case Query.PLUS:
		return new StringValueExp(sval1 + sval2);
	    default:
		throw new BadStringOperationException(opString());
	    }
	}
	
	throw new BadBinaryOpValueExpException(this);
    } 

    /**
     * Returns the string representing the object
     */
    public String toString()  { 
	try {
	    return exp1 + " " + opString() + " " + exp2;
	} catch (BadBinaryOpValueExpException ex) {
	    return "invalid expression";
	}
    } 
    
    private String opString() throws BadBinaryOpValueExpException {
	switch (op) {
	case Query.PLUS:
	    return "+";
	case Query.TIMES:
	    return "*";
	case Query.MINUS:
	    return "-";
	case Query.DIV:
	    return "/";
	}
	
	throw new BadBinaryOpValueExpException(this);
    }

 }