org.springframework.DataSize

스프링 프레임워크 5.1부터 추가된 org.springframework.DataSize 클래스

DataSize를 표현하는데 사용하는 클래스이다.

 

웹개발 하다보면 spring.servlet.multipart.max-file-size=200MB 이런 설정을 볼 수 있는데 그때 사용되는 클래스이다.

스프링부트에서는 컨버터를 지원한다.

• StringToDataSizeConverter
• NumberToDataSizeConverter

1MB 같은 설정을 String으로 설정해줬으면 Byte로 1,048,576 으로 바꿔주는 역할을 한다. 말그대로 Converter

스프링부트가 실행되면서 autoconfiguration 으로 자동으로 다 등록해준다..

org.springframework.DataSize 클래스 

@SuppressWarnings("serial")
public final class DataSize implements Comparable<DataSize>, Serializable {

	/**
	 * The pattern for parsing.
	 */
	private static final Pattern PATTERN = Pattern.compile("^([+\\-]?\\d+)([a-zA-Z]{0,2})$");

	/**
	 * Bytes per Kilobyte.
	 */
	private static final long BYTES_PER_KB = 1024;

	/**
	 * Bytes per Megabyte.
	 */
	private static final long BYTES_PER_MB = BYTES_PER_KB * 1024;

	/**
	 * Bytes per Gigabyte.
	 */
	private static final long BYTES_PER_GB = BYTES_PER_MB * 1024;

	/**
	 * Bytes per Terabyte.
	 */
	private static final 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.
	 * <p>
	 * Examples:
	 * <pre>
	 * "12KB" -- parses as "12 kilobytes"
	 * "5MB"  -- parses as "5 megabytes"
	 * "20"   -- parses as "20 bytes"
	 * </pre>
	 * @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.
	 * <p>
	 * The string starts with a number followed optionally by a unit matching one of the
	 * supported {@linkplain DataUnit suffixes}.
	 * <p>
	 * Examples:
	 * <pre>
	 * "12KB" -- parses as "12 kilobytes"
	 * "5MB"  -- parses as "5 megabytes"
	 * "20"   -- parses as "20 kilobytes" (where the {@code defaultUnit} is {@link DataUnit#KILOBYTES})
	 * </pre>
	 * @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(@Nullable 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);
	}

}

 

StringToDataSizeConverter

final class StringToDataSizeConverter implements GenericConverter {

	@Override
	public Set<ConvertiblePair> getConvertibleTypes() {
		return Collections.singleton(new ConvertiblePair(String.class, DataSize.class));
	}

	@Override
	public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
		if (ObjectUtils.isEmpty(source)) {
			return null;
		}
		return convert(source.toString(), getDataUnit(targetType));
	}

	private DataUnit getDataUnit(TypeDescriptor targetType) {
		DataSizeUnit annotation = targetType.getAnnotation(DataSizeUnit.class);
		return (annotation != null) ? annotation.value() : null;
	}

	private DataSize convert(String source, DataUnit unit) {
		return DataSize.parse(source, unit);
	}

}

 

NumberToDataSizeConverter

final class NumberToDataSizeConverter implements GenericConverter {

	private final StringToDataSizeConverter delegate = new StringToDataSizeConverter();

	@Override
	public Set<ConvertiblePair> getConvertibleTypes() {
		return Collections.singleton(new ConvertiblePair(Number.class, DataSize.class));
	}

	@Override
	public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
		return this.delegate.convert((source != null) ? source.toString() : null, TypeDescriptor.valueOf(String.class),
				targetType);
	}

}

 

참고

https://www.inflearn.com/course/%EC%8A%A4%ED%94%84%EB%A7%81%EB%B6%80%ED%8A%B8-%EC%97%85%EB%8D%B0%EC%9D%B4%ED%8A%B8/dashboard

스프링 부트 업데이트 - 인프런 | 강의

https://futurecreator.github.io/2018/11/02/spring-boot-2-1-0-release/

스프링 부트 Spring Boot 2.1.0 릴리즈!

https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/util/unit/DataSize.html

DataSize (Spring Framework 5.3.22 API)