Java TimeUnit Format formatTime(long dt, TimeUnit input, TimeUnit output, int decimalPlaces)

Description

Returns a formatted time difference string

License

Open Source License

Parameter

Parameter	Description
dt	the time difference
input	the unit of <code>dt</code>
output	the desired output unit of <code>dt</code>
decimalPlaces	the number of decimal places to print or -1 to print all in precision

Return

the formatted time string

Declaration

public static String formatTime(long dt, TimeUnit input, TimeUnit output, int decimalPlaces) 

Method Source Code

//package com.java2s;
/*//  ww  w .ja  v  a 2 s .  c  o  m
 * Copyright (c) 2013 Game Salutes.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser Public License v3
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/lgpl.html
 * 
 * Contributors:
 *     Game Salutes - Repackaging and modifications of original work under University of Chicago and Apache License 2.0 shown below
 * 
 * Repackaging from edu.uchicago.nsit.iteco.utils to com.gamesalutes.utils
 * 
 * Copyright 2008 - 2011 University of Chicago
 * 
 * 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.
 ******************************************************************************/

import java.util.concurrent.TimeUnit;

public class Main {
    /**
     * Returns a formatted time difference string
     * @param dt the time difference
     * @param input the unit of <code>dt</code>
     * @param output the desired output unit of <code>dt</code>
     * @param decimalPlaces the number of decimal places to
     *         print or -1 to print all in precision
     * @return the formatted time string
     */
    public static String formatTime(long dt, TimeUnit input, TimeUnit output, int decimalPlaces) {
        if (input == null)
            throw new NullPointerException("unit");
        if (output == null)
            throw new NullPointerException("output");

        double inputMult;
        double outputMult;
        String strOutUnit;

        switch (input) {
        case MICROSECONDS:
            inputMult = 1.0e-6;
            break;
        case MILLISECONDS:
            inputMult = 1.0e-3;
            break;
        case NANOSECONDS:
            inputMult = 1.0e-9;
            break;
        case SECONDS:
            inputMult = 1.0;
            break;
        default:
            throw new IllegalArgumentException("input=" + input);

        }
        switch (output) {
        case MICROSECONDS:
            outputMult = 1.0e-6;
            strOutUnit = "us";
            break;
        case MILLISECONDS:
            outputMult = 1.0e-3;
            strOutUnit = "ms";
            break;
        case NANOSECONDS:
            outputMult = 1.0e-9;
            strOutUnit = "ns";
            break;
        case SECONDS:
            outputMult = 1.0;
            strOutUnit = "s";
            break;
        default:
            throw new IllegalArgumentException("output=" + output);

        }

        StringBuilder str = new StringBuilder(64);
        double result = dt * inputMult / outputMult;
        String strResult = String.format("%" + (decimalPlaces >= 0 ? "." + decimalPlaces : "") + "f", result);

        str.append(strResult).append(' ').append(strOutUnit);
        return str.toString();

    }

    /**
     * Returns the <code>String</code> form of <code>o</code>.  Unlike
     * <code>String.valueOf(Object)</code>, if <code>o</code> is <code>null</code>
     * an empty <code>String</code> will be returned.
     * 
     * @param o the <code>Object</code>
     * @return string form of <code>o</code>
     */
    public static String toString(Object o) {
        return o != null ? o.toString() : "";
    }
}

Related

1. format(final long duration, final TimeUnit sourceUnit, final TimeUnit min)
2. formatDuration(long time, TimeUnit unit)
3. formatHighest(long duration, final TimeUnit max)
4. formatMillis(long duration, TimeUnit max, TimeUnit min, boolean useAbbreviation)
5. formatMinutesSeconds(final long sourceDuration, final TimeUnit sourceUnit)