Calculable.java

/*
 * Copyright to the original author or authors.
 *
 * Licensed 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.rioproject.watch;

import java.io.Serializable;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * A Calculable is the atomic attribute that is being 'watched'
 */
@SuppressWarnings("unused")
public class Calculable implements Serializable {
    static final long serialVersionUID = 1L;
    /** The identifier for the Calculable */
    private String id;
    /** The value for the Calculable */
    private double value;
    /** Holds value of property when, indicates when the {@code Calculable} was recorded */
    private long when;
    /** Holds Optional detail about the metric */
    private String detail;
    public static final DateFormat DATE_FORMATTER = new SimpleDateFormat("yyyy.MM.dd HH:mm:ss,SSS");

    /**
     * Create a new Calculable
     */
    public Calculable() {
    }

    /**
     * Create a new Calculable that records the time
     * 
     * @param id The identifier for the Calculable
     * @param value The value for the Calculable
     */
    public Calculable(final String id, final double value) {
        this.id = id;
        this.value = value;
        this.when = System.currentTimeMillis();
    }

    /**
     * Create a new Calculable
     *                                                                                  
     * @param id The identifier for this Calculable record
     * @param value The value for the Calculable Record
     * @param when The time when the recorded value was captured
     */
    public Calculable(final String id, final double value, final long when) {
        this(id, value);
        this.when = when;
    }

    /**
     * Getter for property id
     * 
     * @return Value of property id.
     */
    public String getId() {
        return id;
    }

    /**
     * Getter for property value.
     * 
     * @return Value of property value.
     */
    public double getValue() {
        return value;
    }

    /**
     * Setter for property value.
     * 
     * @param value New value of property value.
     */
    public void setValue(final double value) {
        this.value = value;
    }

    /**
     * Getter for property when.
     * 
     * @return Value of property when.
     */
    public long getWhen() {
        return when;
    }

    /**
     * Get the Date that represents the time of the Calculable
     *
     * @return The Date  that represents the time of the Calculable
     */
    public Date getDate(){
        return(new Date(getWhen()));
    }

    public String getDetail() {
        return detail;
    }

    public void setDetail(final String detail) {
        this.detail = detail;
    }

    /**
     * Indicates whether some other object is "equal to" this one.
     * 
     * @param obj the object to compare to this one
     * @return true if the objects are equal
     */
    public boolean equals(final Object obj) {
        if(obj instanceof Calculable) {
            if(getId() == null && ((Calculable)obj).getId() == null)
                return (true);
            else if(getId() == null || ((Calculable)obj).getId() == null)
                return (false);
            else
                return (getId().equals(((Calculable)obj).getId()));
        }
        return (false);
    }

    /**
     * Returns a hash code value for the object.
     * 
     * @return a hash code value for the object.
     */
    public int hashCode() {
        return (id != null) ? id.hashCode() : 0;
    }

    /**
     * Gets an archival representation for this Calculable
     * 
     * @return a string representation in archive format
     * @deprecated Use toString()
     */
    @Deprecated
    public String getArchiveRecord() {
        return toString();
    }

    protected String getFormattedDate() {
        Date date = new Date(when);
        return DATE_FORMATTER.format(date);
    }

    /**
     * Returns a string representation of the {@code Calculable}.
     * 
     * @return String representation of the {@code Calculable}
     */
    public String toString() {
        String s;
        if(getDetail()==null) {
            s = String.format("%s - id: [%s], value: [%s]", getFormattedDate(), getId(), getValue());
        } else {
            s = String.format("%s - id: [%s], value: [%s], detail: [%s]", getFormattedDate(), getId(), getValue(), getDetail());
        }
        return s;
    }
}