Package com.github.marschall.charsequences

Class CharSequences

java.lang.Object

com.github.marschall.charsequences.CharSequences

public final class CharSequences
extends Object

Utility methods for dealing with CharSequence objects.

Method Summary

Modifier and Type	Method	Description
static int	indexOf(CharSequence charSequence, char c)	Searches for the first occurrence of a char within a sequence that's compatible with String.indexOf(int).
static int	indexOf(CharSequence charSequence, char c, int fromIndex)	Searches for the first occurrence of a char within a sequence staring at a given index that's compatible with String.indexOf(int, int).
static int	indexOf(CharSequence charSequence, String subSequence)	Searches for the first occurrence subsequence within a sequence that's compatible with String.indexOf(String):
static boolean	isNumeric(CharSequence charSequence)	Checks if the given char sequences is numeric.
static int	lastIndexOf(CharSequence charSequence, char c)	Searches for the last occurrence of a char within a sequence that's compatible with String.indexOf(int).
static int	parseInt(CharSequence charSequence)	Parses a given char sequence compatible to Integer.parseInt(String).
static int	parseInt(CharSequence charSequence, int beginIndex, int endIndex)	Parses a given char sequence compatible to Integer.parseInt(String).
static long	parseLong(CharSequence charSequence)	Parses a given char sequence compatible to Long.parseLong(String).
static long	parseLong(CharSequence charSequence, int beginIndex, int endIndex)	Parses a given char sequence compatible to Long.parseLong(String).
static CharSequence	removeLeadingBom(CharSequence charSequence)	Removes a leading byte order mark from a sequence if present.
static Iterable<CharSequence>	split(CharSequence charSequence, char delimiter)	Splits the given CharSequence around matches of the given delimiter character.
static boolean	startsWith(CharSequence charSequence, CharSequence prefix)	Tests if the given CharSequence starts with the specified prefix.
static boolean	startsWithBom(CharSequence charSequence)	Checks if a sequence starts with a byte order mark.
static CharSequence	trim(CharSequence charSequence)	Returns a sequence whose value is the given sequence, with any leading and trailing spaces removed.
static UUID	uuidFromCharSequence(CharSequence name)	Creates a UUID from a CharSequence like UUID.fromString(String)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

isNumeric

public static boolean isNumeric(CharSequence charSequence)

Checks if the given char sequences is numeric.

A char sequence is considered to be numeric if it contains entirely out of numbers between 0 and 9. Empty sequences are rejected as are ones with a leading -.

Parameters:

charSequence - the sequence to check

Returns:

if the sequence is entirely made of of number

Throws:

NullPointerException - if the char sequence is null

parseInt

public static int parseInt(CharSequence charSequence,
                           int beginIndex,
                           int endIndex)

Parses a given char sequence compatible to Integer.parseInt(String).

Parameters:

charSequence - the CharSequence containing the int representation to be parsed, null will cause a NumberFormatException to be thrown

beginIndex - the inclusive index at which to star

endIndex - the exclusive index at which to end

Returns:

the integer value represented by the argument in decimal

Throws:

NumberFormatException - if the charSequence does not contain a parsable int

IndexOutOfBoundsException - if beginIndex is less than endIndex, if beginIndex is negative or if endIndex is bigger than the length of charSequence

See Also:

Integer.parseInt(String), isNumeric(CharSequence)

Implementation Note:

no allocation is performed, performance can be 35% to 50% better than Integer#parseInt(String)

parseInt

public static int parseInt(CharSequence charSequence)

Parses a given char sequence compatible to Integer.parseInt(String).

Parameters:

charSequence - the CharSequence containing the int representation to be parsed, null will cause a NumberFormatException to be thrown

Returns:

the integer value represented by the argument in decimal

Throws:

NumberFormatException - if the charSequence does not contain a parsable int

See Also:

Integer.parseInt(String), isNumeric(CharSequence)

Implementation Note:

no allocation is performed, performance can be 35% to 50% better than Integer#parseInt(String)

parseLong

public static long parseLong(CharSequence charSequence)

Parses a given char sequence compatible to Long.parseLong(String).

Parameters:

charSequence - the CharSequence containing the long representation to be parsed, null will cause a NumberFormatException to be thrown

Returns:

the long value represented by the argument in decimal

Throws:

NumberFormatException - if the charSequence does not contain a parsable long

See Also:

Long.parseLong(java.lang.String, int), isNumeric(CharSequence)

Implementation Note:

no allocation is performed, performance can be 20% to 50% better than Long#parseLong(String)

parseLong

public static long parseLong(CharSequence charSequence,
                             int beginIndex,
                             int endIndex)

Parses a given char sequence compatible to Long.parseLong(String).

Parameters:

charSequence - the CharSequence containing the long representation to be parsed, null will cause a NumberFormatException to be thrown

beginIndex - the inclusive index at which to star

endIndex - the exclusive index at which to end

Returns:

the long value represented by the argument in decimal

Throws:

NumberFormatException - if the charSequence does not contain a parsable long

IndexOutOfBoundsException - if beginIndex is less than endIndex, if beginIndex is negative or if endIndex is bigger than the length of charSequence

See Also:

Long.parseLong(java.lang.String, int), isNumeric(CharSequence)

Implementation Note:

no allocation is performed, performance can be 20% to 50% better than Long#parseLong(String)

indexOf

public static int indexOf(CharSequence charSequence,
                          char c)

Searches for the first occurrence of a char within a sequence that's compatible with String.indexOf(int).

Parameters:

charSequence - the sequence within to search, not null

c - the char to search for

Returns:

the index of the first occurrence of the specified char, or -1 if there is no such occurrence

See Also:

String.indexOf(int)

indexOf

public static int indexOf(CharSequence charSequence,
                          char c,
                          int fromIndex)

Searches for the first occurrence of a char within a sequence staring at a given index that's compatible with String.indexOf(int, int).

Parameters:

charSequence - the sequence within to search, not null

c - the char to search for

fromIndex - the index at which to start the search from, if it's larger than the length of this string then -1 is returned if it's negative then it is treated as 0

Returns:

the index of the first occurrence of the specified char after fromIndex, or -1 if there is no such occurrence

See Also:

String.indexOf(int, int)

lastIndexOf

public static int lastIndexOf(CharSequence charSequence,
                              char c)

Searches for the last occurrence of a char within a sequence that's compatible with String.indexOf(int).

Parameters:

charSequence - the sequence within to search, not null

c - the char to search for

Returns:

the index of the last occurrence of the specified char, or -1 if there is no such occurrence

See Also:

String.indexOf(int)

indexOf

public static int indexOf(CharSequence charSequence,
                          String subSequence)

Searches for the first occurrence subsequence within a sequence that's compatible with String.indexOf(String):

Parameters:

charSequence - the sequence within to search, not null

subSequence - the subsequence to search for, not null

Returns:

the index of the first char of the first occurrence of the specified subsequence, or -1 if there is no such occurrence

See Also:

String.indexOf(String)

trim

public static CharSequence trim(CharSequence charSequence)

Returns a sequence whose value is the given sequence, with any leading and trailing spaces removed.

Parameters:

charSequence - the sequence to trim, not null

Returns:

the trimmed sequence

Throws:

NullPointerException - if the given sequence is null

See Also:

String.trim(), CharSequence.subSequence(int, int)

Implementation Note:

allocation avoided if the sequence does not start or end with a space, allocation avoided if the sequence is just spaces

split

public static Iterable<CharSequence> split(CharSequence charSequence,
                                           char delimiter)

Splits the given CharSequence around matches of the given delimiter character.

Parameters:

charSequence - the CharSequence to split

delimiter - the delimiting character

Returns:

iterable of CharSequence computed by splitting the given CharSequence around matches of the given delimiter character

Implementation Note:

the iterable is lazily computed, no backing collection is created, calling Iterable.iterator() multiple times will create a new iterator starting from the first occurrence every time

startsWithBom

public static boolean startsWithBom(CharSequence charSequence)

Checks if a sequence starts with a byte order mark.

Parameters:

charSequence - the CharSequence to check, not null

Returns:

if a sequence starts with a BOM

removeLeadingBom

public static CharSequence removeLeadingBom(CharSequence charSequence)

Removes a leading byte order mark from a sequence if present.

Parameters:

charSequence - the CharSequence from which to remove the BOM, not null

Returns:

a subsequence with the leading BOM removed the same sequence if the first character is not a BOM or the sequence is empty

startsWith

public static boolean startsWith(CharSequence charSequence,
                                 CharSequence prefix)

Tests if the given CharSequence starts with the specified prefix.

Parameters:

charSequence - the CharSequence to test

prefix - the prefix

Returns:

true if the character sequence represented by the prefix argument is a prefix of the character sequence represented by the charSequence argument, false otherwise. Note also that true will be returned if the argument is an empty string or is equal to the given CharSequence on a char by char basis

Throws:

NullPointerException - if any the given sequences is null

See Also:

String.startsWith(String)

uuidFromCharSequence

public static UUID uuidFromCharSequence(CharSequence name)

Creates a UUID from a CharSequence like UUID.fromString(String)

Parameters:

name - the char sequence that specifies a UUID, not null

Returns:

a new UUID with the specified value

Throws:

IllegalArgumentException - if name is not in the format specified

NullPointerException - if name is null

See Also:

UUID.fromString(String), UUID.toString()

Implementation Note:

unlike UUID.fromString(String) performs no allocation besides the UUID, on a 64bit JVM with oop compression a UUID is 32 and the size of a UUID string is 24 bytes for the string plus 88 for the backing character array for a total of 112 bytes (on Java 8 at least)