org.springframework.util.unit.DataSize Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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.springframework.util.unit;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
/**
* A data size, such as '12MB'.
*
* This class models a size in terms of bytes and is immutable and thread-safe.
*
* @author Stephane Nicoll
* @since 5.1
*/
public final class DataSize implements Comparable {
/**
* The pattern for parsing.
*/
private static final Pattern PATTERN = Pattern.compile("^([+\\-]?\\d+)([a-zA-Z]{0,2})$");
/**
* Bytes per Kilobyte.
*/
private static long BYTES_PER_KB = 1024;
/**
* Bytes per Megabyte.
*/
private static long BYTES_PER_MB = BYTES_PER_KB * 1024;
/**
* Bytes per Gigabyte.
*/
private static long BYTES_PER_GB = BYTES_PER_MB * 1024;
/**
* Bytes per Terabyte.
*/
private static long BYTES_PER_TB = BYTES_PER_GB * 1024;
private final long bytes;
private DataSize(long bytes) {
this.bytes = bytes;
}
/**
* Obtain a {@link DataSize} representing the specified number of bytes.
* @param bytes the number of bytes, positive or negative
* @return a {@link DataSize}
*/
public static DataSize ofBytes(long bytes) {
return new DataSize(bytes);
}
/**
* Obtain a {@link DataSize} representing the specified number of kilobytes.
* @param kilobytes the number of kilobytes, positive or negative
* @return a {@link DataSize}
*/
public static DataSize ofKilobytes(long kilobytes) {
return new DataSize(Math.multiplyExact(kilobytes, BYTES_PER_KB));
}
/**
* Obtain a {@link DataSize} representing the specified number of megabytes.
* @param megabytes the number of megabytes, positive or negative
* @return a {@link DataSize}
*/
public static DataSize ofMegabytes(long megabytes) {
return new DataSize(Math.multiplyExact(megabytes, BYTES_PER_MB));
}
/**
* Obtain a {@link DataSize} representing the specified number of gigabytes.
* @param gigabytes the number of gigabytes, positive or negative
* @return a {@link DataSize}
*/
public static DataSize ofGigabytes(long gigabytes) {
return new DataSize(Math.multiplyExact(gigabytes, BYTES_PER_GB));
}
/**
* Obtain a {@link DataSize} representing the specified number of terabytes.
* @param terabytes the number of terabytes, positive or negative
* @return a {@link DataSize}
*/
public static DataSize ofTerabytes(long terabytes) {
return new DataSize(Math.multiplyExact(terabytes, BYTES_PER_TB));
}
/**
* Obtain a {@link DataSize} representing an amount in the specified {@link DataUnit}.
* @param amount the amount of the size, measured in terms of the unit,
* positive or negative
* @return a corresponding {@link DataSize}
*/
public static DataSize of(long amount, DataUnit unit) {
Assert.notNull(unit, "Unit must not be null");
return new DataSize(Math.multiplyExact(amount, unit.size().toBytes()));
}
/**
* Obtain a {@link DataSize} from a text string such as {@code 12MB} using
* {@link DataUnit#BYTES} if no unit is specified.
*
* Examples:
*
* "12KB" -- parses as "12 kilobytes"
* "5MB" -- parses as "5 megabytes"
* "20" -- parses as "20 bytes"
*
* @param text the text to parse
* @return the parsed {@link DataSize}
* @see #parse(CharSequence, DataUnit)
*/
public static DataSize parse(CharSequence text) {
return parse(text, null);
}
/**
* Obtain a {@link DataSize} from a text string such as {@code 12MB} using
* the specified default {@link DataUnit} if no unit is specified.
*
* The string starts with a number followed optionally by a unit matching one of the
* supported {@link DataUnit suffixes}.
*
* Examples:
*
* "12KB" -- parses as "12 kilobytes"
* "5MB" -- parses as "5 megabytes"
* "20" -- parses as "20 kilobytes" (where the {@code defaultUnit} is {@link DataUnit#KILOBYTES})
*
* @param text the text to parse
* @return the parsed {@link DataSize}
*/
public static DataSize parse(CharSequence text, @Nullable DataUnit defaultUnit) {
Assert.notNull(text, "Text must not be null");
try {
Matcher matcher = PATTERN.matcher(text);
Assert.state(matcher.matches(), "Does not match data size pattern");
DataUnit unit = determineDataUnit(matcher.group(2), defaultUnit);
long amount = Long.parseLong(matcher.group(1));
return DataSize.of(amount, unit);
}
catch (Exception ex) {
throw new IllegalArgumentException("'" + text + "' is not a valid data size", ex);
}
}
private static DataUnit determineDataUnit(String suffix, @Nullable DataUnit defaultUnit) {
DataUnit defaultUnitToUse = (defaultUnit != null ? defaultUnit : DataUnit.BYTES);
return (StringUtils.hasLength(suffix) ? DataUnit.fromSuffix(suffix) : defaultUnitToUse);
}
/**
* Checks if this size is negative, excluding zero.
* @return true if this size has a size less than zero bytes
*/
public boolean isNegative() {
return this.bytes < 0;
}
/**
* Return the number of bytes in this instance.
* @return the number of bytes
*/
public long toBytes() {
return this.bytes;
}
/**
* Return the number of kilobytes in this instance.
* @return the number of kilobytes
*/
public long toKilobytes() {
return this.bytes / BYTES_PER_KB;
}
/**
* Return the number of megabytes in this instance.
* @return the number of megabytes
*/
public long toMegabytes() {
return this.bytes / BYTES_PER_MB;
}
/**
* Return the number of gigabytes in this instance.
* @return the number of gigabytes
*/
public long toGigabytes() {
return this.bytes / BYTES_PER_GB;
}
/**
* Return the number of terabytes in this instance.
* @return the number of terabytes
*/
public long toTerabytes() {
return this.bytes / BYTES_PER_TB;
}
@Override
public int compareTo(DataSize other) {
return Long.compare(this.bytes, other.bytes);
}
@Override
public String toString() {
return String.format("%dB", this.bytes);
}
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (other == null || getClass() != other.getClass()) {
return false;
}
DataSize otherSize = (DataSize) other;
return (this.bytes == otherSize.bytes);
}
@Override
public int hashCode() {
return Long.hashCode(this.bytes);
}
}