net.joala.time.TimeFormat.java Source code

Introduction

Here is the source code for net.joala.time.TimeFormat.java

Source

/*
 * Copyright 2012 CoreMedia AG
 *
 * This file is part of Joala.
 *
 * Joala is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Joala 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Joala.  If not, see <http://www.gnu.org/licenses/>.
 */

package net.joala.time;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.Lists;

import javax.annotation.Nonnegative;
import javax.annotation.Nonnull;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.TimeUnit;

/**
 * @since 9/18/12
 */
public final class TimeFormat {
    @VisibleForTesting
    static final int TIMEUNIT_LIMIT = 2;

    private TimeFormat() {
    }

    /**
     * <p>
     * Format the given time amount in a "human readable" way.
     * </p>
     *
     * @param amount   amount of time units
     * @param timeUnit the time unit
     * @return time amount in human readable format (for example converted to seconds or minutes)
     */
    public static String format(@Nonnegative final long amount, @Nonnull final TimeUnit timeUnit) {
        final List<TimeUnit> reverse = Lists.reverse(Arrays.asList(TimeUnit.values()));
        for (final TimeUnit currentUnit : reverse) {
            if (currentUnit.equals(timeUnit) || currentUnit.convert(amount, timeUnit) >= TIMEUNIT_LIMIT) {
                return TimeUnitFormat.getFormat(currentUnit).format(amount, timeUnit);
            }
        }
        throw new IllegalArgumentException(String.format("TimeUnit %s not supported for formatting.", timeUnit));
    }

    // UnusedDeclaration: enum elements are not used directly but by name matching
    // with TimeUnit-element-names. Thus static code analysis will report the enum
    // elements to be unused.
    @SuppressWarnings("UnusedDeclaration")
    private enum TimeUnitFormat {
        NANOSECONDS("ns", TimeUnit.NANOSECONDS), MICROSECONDS("s", TimeUnit.MICROSECONDS), MILLISECONDS("ms",
                TimeUnit.MILLISECONDS), SECONDS("s", TimeUnit.SECONDS), MINUTES("min",
                        TimeUnit.MINUTES), HOURS("h", TimeUnit.HOURS), DAYS("d", TimeUnit.DAYS);

        private final String sign;
        private final TimeUnit timeUnit;

        TimeUnitFormat(final String sign, final TimeUnit timeUnit) {
            this.sign = sign;
            this.timeUnit = timeUnit;
        }

        public String format(final long amount, final TimeUnit sourceUnit) {
            return String.format("%d %s", timeUnit.convert(amount, sourceUnit), sign);
        }

        public static TimeUnitFormat getFormat(final TimeUnit timeUnit) {
            // Simple matching by name; throws IllegalArgumentException if there is no such name.
            return TimeUnitFormat.valueOf(timeUnit.name());
        }
    }
}