Struts example source code file (ELArithmetic.java)

This example Struts source code file (ELArithmetic.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Struts tags/keywords

bigdecimal, bigdecimal, bigdecimaldelegate, biginteger, biginteger, bigintegerdelegate, double, elarithmetic, long, math, number, number, object, object, string

The Struts ELArithmetic.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.struts2.el.lang;

import java.math.BigDecimal;
import java.math.BigInteger;

import org.apache.struts2.el.util.MessageFactory;


/**
 * A helper class of Arithmetic defined by the EL Specification
 * @author Jacob Hookom [jacob@hookom.net]
 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: rjung $
 */
public abstract class ELArithmetic {

    public final static class BigDecimalDelegate extends ELArithmetic {

        protected Number add(Number num0, Number num1) {
            return ((BigDecimal) num0).add((BigDecimal) num1);
        }

        protected Number coerce(Number num) {
            if (num instanceof BigDecimal)
                return num;
            if (num instanceof BigInteger)
                return new BigDecimal((BigInteger) num);
            return new BigDecimal(num.doubleValue());
        }

        protected Number coerce(String str) {
            return new BigDecimal(str);
        }

        protected Number divide(Number num0, Number num1) {
            return ((BigDecimal) num0).divide((BigDecimal) num1,
                    BigDecimal.ROUND_HALF_UP);
        }

        protected Number subtract(Number num0, Number num1) {
            return ((BigDecimal) num0).subtract((BigDecimal) num1);
        }

        protected Number mod(Number num0, Number num1) {
            return new Double(num0.doubleValue() % num1.doubleValue());
        }

        protected Number multiply(Number num0, Number num1) {
            return ((BigDecimal) num0).multiply((BigDecimal) num1);
        }

        public boolean matches(Object obj0, Object obj1) {
            return (obj0 instanceof BigDecimal || obj1 instanceof BigDecimal);
        }
    }

    public final static class BigIntegerDelegate extends ELArithmetic {

        protected Number add(Number num0, Number num1) {
            return ((BigInteger) num0).add((BigInteger) num1);
        }

        protected Number coerce(Number num) {
            if (num instanceof BigInteger)
                return num;
            return new BigInteger(num.toString());
        }

        protected Number coerce(String str) {
            return new BigInteger(str);
        }

        protected Number divide(Number num0, Number num1) {
            return (new BigDecimal((BigInteger) num0)).divide(new BigDecimal((BigInteger) num1), BigDecimal.ROUND_HALF_UP);
        }

        protected Number multiply(Number num0, Number num1) {
            return ((BigInteger) num0).multiply((BigInteger) num1);
        }

        protected Number mod(Number num0, Number num1) {
            return ((BigInteger) num0).mod((BigInteger) num1);
        }

        protected Number subtract(Number num0, Number num1) {
            return ((BigInteger) num0).subtract((BigInteger) num1);
        }

        public boolean matches(Object obj0, Object obj1) {
            return (obj0 instanceof BigInteger || obj1 instanceof BigInteger);
        }
    }

    public final static class DoubleDelegate extends ELArithmetic {

        protected Number add(Number num0, Number num1) {
            // could only be one of these
            if (num0 instanceof BigDecimal) {
                return ((BigDecimal) num0).add(new BigDecimal(num1.doubleValue()));
            } else if (num1 instanceof BigDecimal) {
                return ((new BigDecimal(num0.doubleValue()).add((BigDecimal) num1)));
            }
            return new Double(num0.doubleValue() + num1.doubleValue());
        }

        protected Number coerce(Number num) {
            if (num instanceof Double)
                return num;
            if (num instanceof BigInteger)
                return new BigDecimal((BigInteger) num);
            return new Double(num.doubleValue());
        }

        protected Number coerce(String str) {
            return new Double(str);
        }

        protected Number divide(Number num0, Number num1) {
            return new Double(num0.doubleValue() / num1.doubleValue());
        }

        protected Number mod(Number num0, Number num1) {
            return new Double(num0.doubleValue() % num1.doubleValue());
        }

        protected Number subtract(Number num0, Number num1) {
            // could only be one of these
            if (num0 instanceof BigDecimal) {
                return ((BigDecimal) num0).subtract(new BigDecimal(num1.doubleValue()));
            } else if (num1 instanceof BigDecimal) {
                return ((new BigDecimal(num0.doubleValue()).subtract((BigDecimal) num1)));
            }
            return new Double(num0.doubleValue() - num1.doubleValue());
        }

        protected Number multiply(Number num0, Number num1) {
            // could only be one of these
            if (num0 instanceof BigDecimal) {
                return ((BigDecimal) num0).multiply(new BigDecimal(num1.doubleValue()));
            } else if (num1 instanceof BigDecimal) {
                return ((new BigDecimal(num0.doubleValue()).multiply((BigDecimal) num1)));
            }
            return new Double(num0.doubleValue() * num1.doubleValue());
        }

        public boolean matches(Object obj0, Object obj1) {
            return (obj0 instanceof Double
                    || obj1 instanceof Double
                    || obj0 instanceof Float
                    || obj1 instanceof Float
                    || (obj0 instanceof String && ELSupport
                            .isStringFloat((String) obj0)) || (obj1 instanceof String && ELSupport
                    .isStringFloat((String) obj1)));
        }
    }

    public final static class LongDelegate extends ELArithmetic {

        protected Number add(Number num0, Number num1) {
            return new Long(num0.longValue() + num1.longValue());
        }

        protected Number coerce(Number num) {
            if (num instanceof Long)
                return num;
            return new Long(num.longValue());
        }

        protected Number coerce(String str) {
            return new Long(str);
        }

        protected Number divide(Number num0, Number num1) {
            return new Long(num0.longValue() / num1.longValue());
        }

        protected Number mod(Number num0, Number num1) {
            return new Long(num0.longValue() % num1.longValue());
        }

        protected Number subtract(Number num0, Number num1) {
            return new Long(num0.longValue() - num1.longValue());
        }

        protected Number multiply(Number num0, Number num1) {
            return new Long(num0.longValue() * num1.longValue());
        }

        public boolean matches(Object obj0, Object obj1) {
            return (obj0 instanceof Long || obj1 instanceof Long);
        }
    }

    public final static BigDecimalDelegate BIGDECIMAL = new BigDecimalDelegate();

    public final static BigIntegerDelegate BIGINTEGER = new BigIntegerDelegate();

    public final static DoubleDelegate DOUBLE = new DoubleDelegate();

    public final static LongDelegate LONG = new LongDelegate();

    private final static Long ZERO = new Long(0);

    public final static Number add(final Object obj0, final Object obj1) {
        if (obj0 == null && obj1 == null) {
            return new Long(0);
        }

        final ELArithmetic delegate;
        if (BIGDECIMAL.matches(obj0, obj1))
            delegate = BIGDECIMAL;
        else if (DOUBLE.matches(obj0, obj1))
            delegate = DOUBLE;
        else if (BIGINTEGER.matches(obj0, obj1))
            delegate = BIGINTEGER;
        else
            delegate = LONG;

        Number num0 = delegate.coerce(obj0);
        Number num1 = delegate.coerce(obj1);

        return delegate.add(num0, num1);
    }

    public final static Number mod(final Object obj0, final Object obj1) {
        if (obj0 == null && obj1 == null) {
            return new Long(0);
        }

        final ELArithmetic delegate;
        if (BIGDECIMAL.matches(obj0, obj1))
            delegate = BIGDECIMAL;
        else if (DOUBLE.matches(obj0, obj1))
            delegate = DOUBLE;
        else if (BIGINTEGER.matches(obj0, obj1))
            delegate = BIGINTEGER;
        else
            delegate = LONG;

        Number num0 = delegate.coerce(obj0);
        Number num1 = delegate.coerce(obj1);

        return delegate.mod(num0, num1);
    }

    public final static Number subtract(final Object obj0, final Object obj1) {
        if (obj0 == null && obj1 == null) {
            return new Long(0);
        }

        final ELArithmetic delegate;
        if (BIGDECIMAL.matches(obj0, obj1))
            delegate = BIGDECIMAL;
        else if (DOUBLE.matches(obj0, obj1))
            delegate = DOUBLE;
        else if (BIGINTEGER.matches(obj0, obj1))
            delegate = BIGINTEGER;
        else
            delegate = LONG;

        Number num0 = delegate.coerce(obj0);
        Number num1 = delegate.coerce(obj1);

        return delegate.subtract(num0, num1);
    }

    public final static Number divide(final Object obj0, final Object obj1) {
        if (obj0 == null && obj1 == null) {
            return ZERO;
        }

        final ELArithmetic delegate;
        if (BIGDECIMAL.matches(obj0, obj1))
            delegate = BIGDECIMAL;
        else if (BIGINTEGER.matches(obj0, obj1))
            delegate = BIGDECIMAL;
        else
            delegate = DOUBLE;

        Number num0 = delegate.coerce(obj0);
        Number num1 = delegate.coerce(obj1);

        return delegate.divide(num0, num1);
    }

    public final static Number multiply(final Object obj0, final Object obj1) {
        if (obj0 == null && obj1 == null) {
            return new Long(0);
        }

        final ELArithmetic delegate;
        if (BIGDECIMAL.matches(obj0, obj1))
            delegate = BIGDECIMAL;
        else if (DOUBLE.matches(obj0, obj1))
            delegate = DOUBLE;
        else if (BIGINTEGER.matches(obj0, obj1))
            delegate = BIGINTEGER;
        else
            delegate = LONG;

        Number num0 = delegate.coerce(obj0);
        Number num1 = delegate.coerce(obj1);

        return delegate.multiply(num0, num1);
    }

    public final static boolean isNumber(final Object obj) {
        return (obj != null && isNumberType(obj.getClass()));
    }

    public final static boolean isNumberType(final Class<?> type) {
        return type == Long.TYPE || type == Double.TYPE ||
            type == Byte.TYPE || type == Short.TYPE ||
            type == Integer.TYPE || type == Float.TYPE ||
            Number.class.isAssignableFrom(type);
    }

    /**
     *
     */
    protected ELArithmetic() {
        super();
    }

    protected abstract Number add(final Number num0, final Number num1);

    protected abstract Number multiply(final Number num0, final Number num1);

    protected abstract Number subtract(final Number num0, final Number num1);

    protected abstract Number mod(final Number num0, final Number num1);

    protected abstract Number coerce(final Number num);

    protected final Number coerce(final Object obj) {

        if (isNumber(obj)) {
            return coerce((Number) obj);
        }
        if (obj instanceof String) {
            return coerce((String) obj);
        }
        if (obj == null || "".equals(obj)) {
            return coerce(ZERO);
        }

        if (obj instanceof Character) {
            return coerce(new Short((short) ((Character) obj).charValue()));
        }

        throw new IllegalArgumentException(MessageFactory.get("error.convert",
                obj, obj.getClass(), "Number"));
    }

    protected abstract Number coerce(final String str);

    protected abstract Number divide(final Number num0, final Number num1);

    protected abstract boolean matches(final Object obj0, final Object obj1);

}