Package com.google.common.base
Class Ascii
- java.lang.Object
-
- com.google.common.base.Ascii
-
@GwtCompatible public final class Ascii extends Object
Static methods pertaining to ASCII characters (those in the range of values0x00
through0x7F
), and to strings containing such characters.ASCII utilities also exist in other classes of this package:
Charsets.US_ASCII
specifies theCharset
of ASCII characters.CharMatcher.ASCII
matches ASCII characters and provides text processing methods which operate only on the ASCII characters of a string.
- Since:
- 7.0
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-
Field Summary
Fields Modifier and Type Field Description static byte
ACK
Acknowledge: A communication control character transmitted by a receiver as an affirmative response to a sender.static byte
BEL
Bell ('\a'): A character for use when there is a need to call for human attention.static byte
BS
Backspace ('\b'): A format effector which controls the movement of the printing position one printing space backward on the same printing line.static byte
CAN
Cancel: A control character used to indicate that the data with which it is sent is in error or is to be disregarded.static byte
CR
Carriage Return ('\r'): A format effector which controls the movement of the printing position to the first printing position on the same printing line.static byte
DC1
Device Control 1.static byte
DC2
Device Control 2.static byte
DC3
Device Control 3.static byte
DC4
Device Control 4.static byte
DEL
Delete: This character is used primarily to "erase" or "obliterate" erroneous or unwanted characters in perforated tape.static byte
DLE
Data Link Escape: A communication control character which will change the meaning of a limited number of contiguously following characters.static byte
EM
End of Medium: A control character associated with the sent data which may be used to identify the physical end of the medium, or the end of the used, or wanted, portion of information recorded on a medium.static byte
ENQ
Enquiry: A communication control character used in data communication systems as a request for a response from a remote station.static byte
EOT
End of Transmission: A communication control character used to indicate the conclusion of a transmission, which may have contained one or more texts and any associated headings.static byte
ESC
Escape: A control character intended to provide code extension (supplementary characters) in general information interchange.static byte
ETB
End of Transmission Block: A communication control character used to indicate the end of a block of data for communication purposes.static byte
ETX
End of Text: A communication control character used to terminate a sequence of characters started with STX and transmitted as an entity.static byte
FF
Form Feed ('\f'): A format effector which controls the movement of the printing position to the first pre-determined printing line on the next form or page.static byte
FS
File Separator: These four information separators may be used within data in optional fashion, except that their hierarchical relationship shall be: FS is the most inclusive, then GS, then RS, and US is least inclusive.static byte
GS
Group Separator: These four information separators may be used within data in optional fashion, except that their hierarchical relationship shall be: FS is the most inclusive, then GS, then RS, and US is least inclusive.static byte
HT
Horizontal Tabulation ('\t'): A format effector which controls the movement of the printing position to the next in a series of predetermined positions along the printing line.static byte
LF
Line Feed ('\n'): A format effector which controls the movement of the printing position to the next printing line.static char
MAX
The maximum value of an ASCII character.static char
MIN
The minimum value of an ASCII character.static byte
NAK
Negative Acknowledge: A communication control character transmitted by a receiver as a negative response to the sender.static byte
NL
Alternate name forLF
.static byte
NUL
Null ('\0'): The all-zeros character which may serve to accomplish time fill and media fill.static byte
RS
Record Separator: These four information separators may be used within data in optional fashion, except that their hierarchical relationship shall be: FS is the most inclusive, then GS, then RS, and US is least inclusive.static byte
SI
Shift In: A control character indicating that the code combinations which follow shall be interpreted according to the standard code table.static byte
SO
Shift Out: A control character indicating that the code combinations which follow shall be interpreted as outside of the character set of the standard code table until a Shift In character is reached.static byte
SOH
Start of Heading: A communication control character used at the beginning of a sequence of characters which constitute a machine-sensible address or routing information.static byte
SP
Space: A normally non-printing graphic character used to separate words.static byte
SPACE
Alternate name forSP
.static byte
STX
Start of Text: A communication control character which precedes a sequence of characters that is to be treated as an entity and entirely transmitted through to the ultimate destination.static byte
SUB
Substitute: A character that may be substituted for a character which is determined to be invalid or in error.static byte
SYN
Synchronous Idle: A communication control character used by a synchronous transmission system in the absence of any other character to provide a signal from which synchronism may be achieved or retained.static byte
US
Unit Separator: These four information separators may be used within data in optional fashion, except that their hierarchical relationship shall be: FS is the most inclusive, then GS, then RS, and US is least inclusive.static byte
VT
Vertical Tabulation ('\v'): A format effector which controls the movement of the printing position to the next in a series of predetermined printing lines.static byte
XOFF
Transmission off.static byte
XON
Transmission On: Although originally defined as DC1, this ASCII control character is now better known as the XON code used for software flow control in serial communications.
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Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method Description static boolean
isLowerCase(char c)
Indicates whetherc
is one of the twenty-six lowercase ASCII alphabetic characters between'a'
and'z'
inclusive.static boolean
isUpperCase(char c)
Indicates whetherc
is one of the twenty-six uppercase ASCII alphabetic characters between'A'
and'Z'
inclusive.static char
toLowerCase(char c)
If the argument is an uppercase ASCII character returns the lowercase equivalent.static String
toLowerCase(CharSequence chars)
Returns a copy of the input character sequence in which all uppercase ASCII characters have been converted to lowercase.static String
toLowerCase(String string)
Returns a copy of the input string in which all uppercase ASCII characters have been converted to lowercase.static char
toUpperCase(char c)
If the argument is a lowercase ASCII character returns the uppercase equivalent.static String
toUpperCase(CharSequence chars)
Returns a copy of the input character sequence in which all lowercase ASCII characters have been converted to uppercase.static String
toUpperCase(String string)
Returns a copy of the input string in which all lowercase ASCII characters have been converted to uppercase.
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-
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Field Detail
-
NUL
public static final byte NUL
Null ('\0'): The all-zeros character which may serve to accomplish time fill and media fill. Normally used as a C string terminator.Although RFC 20 names this as "Null", note that it is distinct from the C/C++ "NULL" pointer.
- Since:
- 8.0
- See Also:
- Constant Field Values
-
SOH
public static final byte SOH
Start of Heading: A communication control character used at the beginning of a sequence of characters which constitute a machine-sensible address or routing information. Such a sequence is referred to as the "heading." An STX character has the effect of terminating a heading.- Since:
- 8.0
- See Also:
- Constant Field Values
-
STX
public static final byte STX
Start of Text: A communication control character which precedes a sequence of characters that is to be treated as an entity and entirely transmitted through to the ultimate destination. Such a sequence is referred to as "text." STX may be used to terminate a sequence of characters started by SOH.- Since:
- 8.0
- See Also:
- Constant Field Values
-
ETX
public static final byte ETX
End of Text: A communication control character used to terminate a sequence of characters started with STX and transmitted as an entity.- Since:
- 8.0
- See Also:
- Constant Field Values
-
EOT
public static final byte EOT
End of Transmission: A communication control character used to indicate the conclusion of a transmission, which may have contained one or more texts and any associated headings.- Since:
- 8.0
- See Also:
- Constant Field Values
-
ENQ
public static final byte ENQ
Enquiry: A communication control character used in data communication systems as a request for a response from a remote station. It may be used as a "Who Are You" (WRU) to obtain identification, or may be used to obtain station status, or both.- Since:
- 8.0
- See Also:
- Constant Field Values
-
ACK
public static final byte ACK
Acknowledge: A communication control character transmitted by a receiver as an affirmative response to a sender.- Since:
- 8.0
- See Also:
- Constant Field Values
-
BEL
public static final byte BEL
Bell ('\a'): A character for use when there is a need to call for human attention. It may control alarm or attention devices.- Since:
- 8.0
- See Also:
- Constant Field Values
-
BS
public static final byte BS
Backspace ('\b'): A format effector which controls the movement of the printing position one printing space backward on the same printing line. (Applicable also to display devices.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
HT
public static final byte HT
Horizontal Tabulation ('\t'): A format effector which controls the movement of the printing position to the next in a series of predetermined positions along the printing line. (Applicable also to display devices and the skip function on punched cards.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
LF
public static final byte LF
Line Feed ('\n'): A format effector which controls the movement of the printing position to the next printing line. (Applicable also to display devices.) Where appropriate, this character may have the meaning "New Line" (NL), a format effector which controls the movement of the printing point to the first printing position on the next printing line. Use of this convention requires agreement between sender and recipient of data.- Since:
- 8.0
- See Also:
- Constant Field Values
-
NL
public static final byte NL
Alternate name forLF
. (LF
is preferred.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
VT
public static final byte VT
Vertical Tabulation ('\v'): A format effector which controls the movement of the printing position to the next in a series of predetermined printing lines. (Applicable also to display devices.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
FF
public static final byte FF
Form Feed ('\f'): A format effector which controls the movement of the printing position to the first pre-determined printing line on the next form or page. (Applicable also to display devices.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
CR
public static final byte CR
Carriage Return ('\r'): A format effector which controls the movement of the printing position to the first printing position on the same printing line. (Applicable also to display devices.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
SO
public static final byte SO
Shift Out: A control character indicating that the code combinations which follow shall be interpreted as outside of the character set of the standard code table until a Shift In character is reached.- Since:
- 8.0
- See Also:
- Constant Field Values
-
SI
public static final byte SI
Shift In: A control character indicating that the code combinations which follow shall be interpreted according to the standard code table.- Since:
- 8.0
- See Also:
- Constant Field Values
-
DLE
public static final byte DLE
Data Link Escape: A communication control character which will change the meaning of a limited number of contiguously following characters. It is used exclusively to provide supplementary controls in data communication networks.- Since:
- 8.0
- See Also:
- Constant Field Values
-
DC1
public static final byte DC1
Device Control 1. Characters for the control of ancillary devices associated with data processing or telecommunication systems, more especially switching devices "on" or "off." (If a single "stop" control is required to interrupt or turn off ancillary devices, DC4 is the preferred assignment.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
XON
public static final byte XON
Transmission On: Although originally defined as DC1, this ASCII control character is now better known as the XON code used for software flow control in serial communications. The main use is restarting the transmission after the communication has been stopped by the XOFF control code.- Since:
- 8.0
- See Also:
- Constant Field Values
-
DC2
public static final byte DC2
Device Control 2. Characters for the control of ancillary devices associated with data processing or telecommunication systems, more especially switching devices "on" or "off." (If a single "stop" control is required to interrupt or turn off ancillary devices, DC4 is the preferred assignment.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
DC3
public static final byte DC3
Device Control 3. Characters for the control of ancillary devices associated with data processing or telecommunication systems, more especially switching devices "on" or "off." (If a single "stop" control is required to interrupt or turn off ancillary devices, DC4 is the preferred assignment.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
XOFF
public static final byte XOFF
Transmission off. SeeXON
for explanation.- Since:
- 8.0
- See Also:
- Constant Field Values
-
DC4
public static final byte DC4
Device Control 4. Characters for the control of ancillary devices associated with data processing or telecommunication systems, more especially switching devices "on" or "off." (If a single "stop" control is required to interrupt or turn off ancillary devices, DC4 is the preferred assignment.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
NAK
public static final byte NAK
Negative Acknowledge: A communication control character transmitted by a receiver as a negative response to the sender.- Since:
- 8.0
- See Also:
- Constant Field Values
-
SYN
public static final byte SYN
Synchronous Idle: A communication control character used by a synchronous transmission system in the absence of any other character to provide a signal from which synchronism may be achieved or retained.- Since:
- 8.0
- See Also:
- Constant Field Values
-
ETB
public static final byte ETB
End of Transmission Block: A communication control character used to indicate the end of a block of data for communication purposes. ETB is used for blocking data where the block structure is not necessarily related to the processing format.- Since:
- 8.0
- See Also:
- Constant Field Values
-
CAN
public static final byte CAN
Cancel: A control character used to indicate that the data with which it is sent is in error or is to be disregarded.- Since:
- 8.0
- See Also:
- Constant Field Values
-
EM
public static final byte EM
End of Medium: A control character associated with the sent data which may be used to identify the physical end of the medium, or the end of the used, or wanted, portion of information recorded on a medium. (The position of this character does not necessarily correspond to the physical end of the medium.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
SUB
public static final byte SUB
Substitute: A character that may be substituted for a character which is determined to be invalid or in error.- Since:
- 8.0
- See Also:
- Constant Field Values
-
ESC
public static final byte ESC
Escape: A control character intended to provide code extension (supplementary characters) in general information interchange. The Escape character itself is a prefix affecting the interpretation of a limited number of contiguously following characters.- Since:
- 8.0
- See Also:
- Constant Field Values
-
FS
public static final byte FS
File Separator: These four information separators may be used within data in optional fashion, except that their hierarchical relationship shall be: FS is the most inclusive, then GS, then RS, and US is least inclusive. (The content and length of a File, Group, Record, or Unit are not specified.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
GS
public static final byte GS
Group Separator: These four information separators may be used within data in optional fashion, except that their hierarchical relationship shall be: FS is the most inclusive, then GS, then RS, and US is least inclusive. (The content and length of a File, Group, Record, or Unit are not specified.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
RS
public static final byte RS
Record Separator: These four information separators may be used within data in optional fashion, except that their hierarchical relationship shall be: FS is the most inclusive, then GS, then RS, and US is least inclusive. (The content and length of a File, Group, Record, or Unit are not specified.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
US
public static final byte US
Unit Separator: These four information separators may be used within data in optional fashion, except that their hierarchical relationship shall be: FS is the most inclusive, then GS, then RS, and US is least inclusive. (The content and length of a File, Group, Record, or Unit are not specified.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
SP
public static final byte SP
Space: A normally non-printing graphic character used to separate words. It is also a format effector which controls the movement of the printing position, one printing position forward. (Applicable also to display devices.)- Since:
- 8.0
- See Also:
- Constant Field Values
-
SPACE
public static final byte SPACE
Alternate name forSP
.- Since:
- 8.0
- See Also:
- Constant Field Values
-
DEL
public static final byte DEL
Delete: This character is used primarily to "erase" or "obliterate" erroneous or unwanted characters in perforated tape.- Since:
- 8.0
- See Also:
- Constant Field Values
-
MIN
public static final char MIN
The minimum value of an ASCII character.- Since:
- 9.0 (was type
int
before 12.0) - See Also:
- Constant Field Values
-
MAX
public static final char MAX
The maximum value of an ASCII character.- Since:
- 9.0 (was type
int
before 12.0) - See Also:
- Constant Field Values
-
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Method Detail
-
toLowerCase
public static String toLowerCase(String string)
Returns a copy of the input string in which all uppercase ASCII characters have been converted to lowercase. All other characters are copied without modification.
-
toLowerCase
public static String toLowerCase(CharSequence chars)
Returns a copy of the input character sequence in which all uppercase ASCII characters have been converted to lowercase. All other characters are copied without modification.- Since:
- 14.0
-
toLowerCase
public static char toLowerCase(char c)
If the argument is an uppercase ASCII character returns the lowercase equivalent. Otherwise returns the argument.
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toUpperCase
public static String toUpperCase(String string)
Returns a copy of the input string in which all lowercase ASCII characters have been converted to uppercase. All other characters are copied without modification.
-
toUpperCase
public static String toUpperCase(CharSequence chars)
Returns a copy of the input character sequence in which all lowercase ASCII characters have been converted to uppercase. All other characters are copied without modification.- Since:
- 14.0
-
toUpperCase
public static char toUpperCase(char c)
If the argument is a lowercase ASCII character returns the uppercase equivalent. Otherwise returns the argument.
-
isLowerCase
public static boolean isLowerCase(char c)
Indicates whetherc
is one of the twenty-six lowercase ASCII alphabetic characters between'a'
and'z'
inclusive. All others (including non-ASCII characters) returnfalse
.
-
isUpperCase
public static boolean isUpperCase(char c)
Indicates whetherc
is one of the twenty-six uppercase ASCII alphabetic characters between'A'
and'Z'
inclusive. All others (including non-ASCII characters) returnfalse
.
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