org.hbird.exchange.core.Parameter.java Source code

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Here is the source code for org.hbird.exchange.core.Parameter.java

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/**
 * Licensed to the Hummingbird Foundation (HF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The HF 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.hbird.exchange.core;

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

import org.apache.commons.lang3.builder.ToStringBuilder;
import org.apache.commons.lang3.builder.ToStringStyle;

/**
 * A NUMERICAL parameter. The parameter type is at the core of the information model. It
 * is used to describe a name-value pair, attaching the meta-data for description
 * and unit.
 * 
 * There is no predefined set of parameters in the form of a database. Creating
 * a new parameter is simply the creation of a Parameter with a new name.
 * 
 */
public class Parameter extends ApplicableTo {

    /** The unique UID. */
    private static final long serialVersionUID = 889400984561961325L;

    /** The value of the parameter. May be any type. */
    protected Number value;

    /** The unit of the value. */
    protected String unit;

    /**
     * Creates a Parameter with a timestamp set to 'now'.
     * 
     * @param name The name of the parameter
     * @param description A description of the parameter.
     * @param value An object holding the value.
     * @param unit The unit of the value.
     */
    public Parameter(String ID, String name) {
        super(ID, name);
    }

    /**
     * Returns the value of the Parameter as an Object.
     * 
     * @return An Object holding the value. The class type can of cause be found using
     *         reflection, or through the 'clazz' attribute.
     */
    public Number getValue() {
        return value;
    }

    public void setDoubleValue(double value) {
        this.value = value;
    }

    public double asDouble() {
        return value.doubleValue();
    }

    public int asInt() {
        return value.intValue();
    }

    /**
     * Setter for the value. Will also set the 'clazz' attribute to the Java name of the
     * class set as value.
     * 
     * @param value The value to be set.
     */
    public void setValue(Number value) {
        this.value = value;
    }

    /**
     * Returns the string representing the unit of this parameter.
     * 
     * @return STring representing the unit.
     */
    public String getUnit() {
        return unit;
    }

    /**
     * @param unit the unit to set
     */
    public void setUnit(String unit) {
        this.unit = unit;
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Comparable#compareTo(java.lang.Object)
     * 
     * Notice that the method has extra been implemented to allow comparison of types that are
     * not the same, i.e. Integer and Double.
     */
    @Override
    public int compareTo(EntityInstance cTo) {

        if (cTo instanceof Parameter) {
            Parameter rhs = (Parameter) cTo;
            if (this.value instanceof Short && rhs.value instanceof Short) {
                return ((Short) this.value).compareTo((Short) rhs.value);
            } else if (this.value instanceof Long && rhs.value instanceof Long) {
                return ((Long) this.value).compareTo((Long) rhs.value);
            } else if (this.value instanceof Integer && rhs.value instanceof Integer) {
                return ((Integer) this.value).compareTo((Integer) rhs.value);
            } else if (this.value instanceof Float && rhs.value instanceof Float) {
                return ((Float) this.value).compareTo((Float) rhs.value);
            } else if (this.value instanceof Double && rhs.value instanceof Double) {
                return ((Double) this.value).compareTo((Double) rhs.value);
            } else if (this.value instanceof Byte && rhs.value instanceof Byte) {
                return ((Byte) this.value).compareTo((Byte) rhs.value);
            } else if (this.value instanceof BigInteger && rhs.value instanceof BigInteger) {
                return ((BigInteger) this.value).compareTo((BigInteger) rhs.value);
            } else if (this.value instanceof BigDecimal && rhs.value instanceof BigDecimal) {
                return ((BigDecimal) this.value).compareTo((BigDecimal) rhs.value);
            } else {
                String message = String.format("Failed to compare values of %s and %s; value types are %s and %s",
                        this.toString(), rhs.toString(), this.value != null ? this.value.getClass() : "null",
                        rhs.value != null ? rhs.value.getClass() : "null");
                throw new RuntimeException(message);
            }
        }

        return -1;
    }

    @Override
    public String toString() {
        ToStringBuilder builder = new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE);
        builder.append("ID", getInstanceID());
        builder.append("name", name);
        builder.append("value", value);
        builder.append("issuedBy", issuedBy);
        builder.append("applicableTo", applicableTo);
        return builder.build();
    }
}