net.sf.mmm.util.io.api

Enum ByteOrderMark

java.lang.Object

java.lang.Enum<ByteOrderMark>

net.sf.mmm.util.io.api.ByteOrderMark

All Implemented Interfaces:

Serializable, Comparable<ByteOrderMark>

public enum ByteOrderMark
extends Enum<ByteOrderMark>

This type represents a Byte-Order-Mark (BOM) of an Unicode-Transformation-Format (UTF).

Since:

1.0.1

Author:

Joerg Hohwiller (hohwille at users.sourceforge.net)

Enum Constant Summary

Enum Constants

Enum Constant and Description
UTF_16_BE The ByteOrderMark for UTF-16BE: 0xfe 0xff
UTF_16_LE The ByteOrderMark for UTF16-LE: 0xff 0xfe
UTF_32_BE The ByteOrderMark for UTF-32BE: 0x00 0x00 0xfe 0xff
UTF_32_LE The ByteOrderMark for UTF-32LE: 0xff 0xfe 0x00 0x00
UTF_8 The ByteOrderMark for UTF-8: 0xef 0xbb 0xbf

Field Summary

Fields

Modifier and Type	Field and Description
private static byte[]	MAGIC_BYTES_UTF16_BE
private static byte[]	MAGIC_BYTES_UTF16_LE
private static byte[]	MAGIC_BYTES_UTF32_BE
private static byte[]	MAGIC_BYTES_UTF32_LE
private static byte[]	MAGIC_BYTES_UTF8

Method Summary

Modifier and Type	Method and Description
static ByteOrderMark	detect(byte[] bytes, int offset) This method detects the ByteOrderMark that may be present in the given bytes starting at offset.
protected abstract byte[]	getBytes() This method gets the bytes of this BOM.
abstract String	getEncoding() This method gets the encoding indicated by this ByteOrderMark.
int	getLength() This method gets the number of bytes of this ByteOrderMark.
boolean	isPresent(byte[] bytes, int offset) This method detects if this ByteOrderMark is present in the given bytes.
static ByteOrderMark	valueOf(String name) Returns the enum constant of this type with the specified name.
static ByteOrderMark[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

UTF_8

public static final ByteOrderMark UTF_8

The ByteOrderMark for UTF-8:
0xef 0xbb 0xbf

UTF_16_BE

public static final ByteOrderMark UTF_16_BE

The ByteOrderMark for UTF-16BE:
0xfe 0xff

UTF_16_LE

public static final ByteOrderMark UTF_16_LE

The ByteOrderMark for UTF16-LE:
0xff 0xfe

UTF_32_BE

public static final ByteOrderMark UTF_32_BE

The ByteOrderMark for UTF-32BE:
0x00 0x00 0xfe 0xff

UTF_32_LE

public static final ByteOrderMark UTF_32_LE

The ByteOrderMark for UTF-32LE:
0xff 0xfe 0x00 0x00

Field Detail

MAGIC_BYTES_UTF8

private static final byte[] MAGIC_BYTES_UTF8

MAGIC_BYTES_UTF16_BE

private static final byte[] MAGIC_BYTES_UTF16_BE

MAGIC_BYTES_UTF16_LE

private static final byte[] MAGIC_BYTES_UTF16_LE

MAGIC_BYTES_UTF32_BE

private static final byte[] MAGIC_BYTES_UTF32_BE

MAGIC_BYTES_UTF32_LE

private static final byte[] MAGIC_BYTES_UTF32_LE

Method Detail

values

public static ByteOrderMark[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (ByteOrderMark c : ByteOrderMark.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static ByteOrderMark valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

getEncoding

public abstract String getEncoding()

This method gets the encoding indicated by this ByteOrderMark.

Returns:

the encoding.

getLength

public final int getLength()

This method gets the number of bytes of this ByteOrderMark.

Returns:

the length.

isPresent

public final boolean isPresent(byte[] bytes,
                               int offset)

This method detects if this ByteOrderMark is present in the given bytes.
NOTE:
A BOM may only occur at the head of your data (file, payload, etc.).
ATTENTION:
Please note that binary data may accidently have header bytes that represent this ByteOrderMark. This method can NOT know this and will return true even if the data is NOT encoded with the according encoding. Therefore you should only use this method for the header of textual data.

Parameters:

bytes - is the buffer with the bytes to check.

offset - is the index of the first data-byte in bytes. Will typically be 0 .

Returns:

true if this BOM was detected in the

getBytes

protected abstract byte[] getBytes()

This method gets the bytes of this BOM.

Returns:

the magic bytes of this BOM.

detect

public static ByteOrderMark detect(byte[] bytes,
                                   int offset)

This method detects the ByteOrderMark that may be present in the given bytes starting at offset.
ATTENTION:
Please note that binary data may accidently have header bytes that represent a ByteOrderMark. This method can NOT know this and will return that ByteOrderMark even if the data is NOT encoded with the according encoding. Therefore you should only use this method for the header of textual data.

Parameters:

bytes - is the buffer with the bytes to check.

offset - is the index of the first data-byte in bytes. Will typically be 0 .

Returns:

the detected ByteOrderMark or null if the given bytes have no BOM.