Scanner
public
final
class
Scanner
extends Object
implements
Closeable,
Iterator<String>
java.lang.Object | |
↳ | java.util.Scanner |
A simple text scanner which can parse primitive types and strings using regular expressions.
A Scanner
breaks its input into tokens using a
delimiter pattern, which by default matches whitespace. The resulting
tokens may then be converted into values of different types using the
various next
methods.
For example, this code allows a user to read a number from
System.in
:
Scanner sc = new Scanner(System.in); int i = sc.nextInt();
As another example, this code allows long
types to be
assigned from entries in a file myNumbers
:
Scanner sc = new Scanner(new File("myNumbers")); while (sc.hasNextLong()) { long aLong = sc.nextLong(); }
The scanner can also use delimiters other than whitespace. This example reads several items in from a string:
String input = "1 fish 2 fish red fish blue fish"; Scanner s = new Scanner(input).useDelimiter("\\s*fish\\s*"); System.out.println(s.nextInt()); System.out.println(s.nextInt()); System.out.println(s.next()); System.out.println(s.next()); s.close();
prints the following output:
1 2 red blue
The same output can be generated with this code, which uses a regular expression to parse all four tokens at once:
String input = "1 fish 2 fish red fish blue fish"; Scanner s = new Scanner(input); s.findInLine("(\\d+) fish (\\d+) fish (\\w+) fish (\\w+)"); MatchResult result = s.match(); for (int i=1; i<=result.groupCount(); i++) System.out.println(result.group(i)); s.close();
The default whitespace delimiter used
by a scanner is as recognized by Character.isWhitespace()
. The reset()
method will reset the value of the scanner's delimiter to the default
whitespace delimiter regardless of whether it was previously changed.
A scanning operation may block waiting for input.
The next()
and hasNext()
methods and their
companion methods (such as nextInt()
and
hasNextInt()
) first skip any input that matches the delimiter
pattern, and then attempt to return the next token. Both hasNext()
and next()
methods may block waiting for further input. Whether a
hasNext()
method blocks has no connection to whether or not its
associated next()
method will block. The tokens()
method
may also block waiting for input.
The findInLine()
,
findWithinHorizon()
,
skip()
, and findAll()
methods operate independently of the delimiter pattern. These methods will
attempt to match the specified pattern with no regard to delimiters in the
input and thus can be used in special circumstances where delimiters are
not relevant. These methods may block waiting for more input.
When a scanner throws an InputMismatchException
, the scanner
will not pass the token that caused the exception, so that it may be
retrieved or skipped via some other method.
Depending upon the type of delimiting pattern, empty tokens may be
returned. For example, the pattern "\\s+"
will return no empty
tokens since it matches multiple instances of the delimiter. The delimiting
pattern "\\s"
could return empty tokens since it only passes one
space at a time.
A scanner can read text from any object which implements the Readable
interface. If an invocation of the underlying
readable's read()
method throws an IOException
then the scanner assumes that the end of the input
has been reached. The most recent IOException
thrown by the
underlying readable can be retrieved via the ioException()
method.
When a Scanner
is closed, it will close its input source
if the source implements the Closeable
interface.
A Scanner
is not safe for multithreaded use without
external synchronization.
Unless otherwise mentioned, passing a null
parameter into
any method of a Scanner
will cause a
NullPointerException
to be thrown.
A scanner will default to interpreting numbers as decimal unless a
different radix has been set by using the useRadix(int)
method. The
reset()
method will reset the value of the scanner's radix to
10
regardless of whether it was previously changed.
Localized numbers
An instance of this class is capable of scanning numbers in the standard
formats as well as in the formats of the scanner's locale. A scanner's
initial locale is the value returned by the Locale.getDefault(Locale.Category.FORMAT)
method; it may be changed via the useLocale()
method. The reset()
method will reset the value of the
scanner's locale to the initial locale regardless of whether it was
previously changed.
The localized formats are defined in terms of the following parameters,
which for a particular locale are taken from that locale's DecimalFormat
object, df
, and its and
DecimalFormatSymbols
object,
dfs
.
- LocalGroupSeparator
- The character used to separate thousands groups, i.e.,
dfs.
getGroupingSeparator()
- LocalDecimalSeparator
- The character used for the decimal point, i.e.,
dfs.
getDecimalSeparator()
- LocalPositivePrefix
- The string that appears before a positive number (may be empty), i.e.,
df.
getPositivePrefix()
- LocalPositiveSuffix
- The string that appears after a positive number (may be empty), i.e.,
df.
getPositiveSuffix()
- LocalNegativePrefix
- The string that appears before a negative number (may be empty), i.e.,
df.
getNegativePrefix()
- LocalNegativeSuffix
- The string that appears after a negative number (may be empty), i.e.,
df.
getNegativeSuffix()
- LocalNaN
- The string that represents not-a-number for floating-point values, i.e.,
dfs.
getNaN()
- LocalInfinity
- The string that represents infinity for floating-point values, i.e.,
dfs.
getInfinity()
Number syntax
The strings that can be parsed as numbers by an instance of this class are specified in terms of the following regular-expression grammar, where Rmax is the highest digit in the radix being used (for example, Rmax is 9 in base 10).
- NonAsciiDigit:
- A non-ASCII character c for which
Character.isDigit
(c)
returns true - Non0Digit:
[1-
Rmax] |
NonASCIIDigit- Digit:
[0-
Rmax] |
NonASCIIDigit- GroupedNumeral:
(
Non0Digit Digit?
Digit?
(
LocalGroupSeparator Digit Digit Digit)+ )
- Numeral:
( (
Digit+ ) |
GroupedNumeral)
- Integer:
( [-+]? (
Numeral) )
|
LocalPositivePrefix Numeral LocalPositiveSuffix|
LocalNegativePrefix Numeral LocalNegativeSuffix- DecimalNumeral:
- Numeral
|
Numeral LocalDecimalSeparator Digit*
|
LocalDecimalSeparator Digit+
- Exponent:
( [eE] [+-]?
Digit+ )
- Decimal:
( [-+]?
DecimalNumeral Exponent? )
|
LocalPositivePrefix DecimalNumeral LocalPositiveSuffix Exponent?
|
LocalNegativePrefix DecimalNumeral LocalNegativeSuffix Exponent?
- HexFloat:
[-+]? 0[xX][0-9a-fA-F]*\.[0-9a-fA-F]+ ([pP][-+]?[0-9]+)?
- NonNumber:
NaN |
LocalNan| Infinity |
LocalInfinity- SignedNonNumber:
( [-+]?
NonNumber)
|
LocalPositivePrefix NonNumber LocalPositiveSuffix|
LocalNegativePrefix NonNumber LocalNegativeSuffix- Float:
- Decimal
|
HexFloat|
SignedNonNumber
Whitespace is not significant in the above regular expressions.
Summary
Public constructors | |
---|---|
Scanner(File source)
Constructs a new |
|
Scanner(File source, String charsetName)
Constructs a new |
|
Scanner(File source, Charset charset)
Constructs a new |
|
Scanner(InputStream source)
Constructs a new |
|
Scanner(InputStream source, String charsetName)
Constructs a new |
|
Scanner(InputStream source, Charset charset)
Constructs a new |
|
Scanner(Readable source)
Constructs a new |
|
Scanner(String source)
Constructs a new |
|
Scanner(ReadableByteChannel source)
Constructs a new |
|
Scanner(ReadableByteChannel source, String charsetName)
Constructs a new |
|
Scanner(ReadableByteChannel source, Charset charset)
Constructs a new |
|
Scanner(Path source)
Constructs a new |
|
Scanner(Path source, String charsetName)
Constructs a new |
|
Scanner(Path source, Charset charset)
Constructs a new |
Public methods | |
---|---|
void
|
close()
Closes this scanner. |
Pattern
|
delimiter()
Returns the |
Stream<MatchResult>
|
findAll(String patString)
Returns a stream of match results that match the provided pattern string. |
Stream<MatchResult>
|
findAll(Pattern pattern)
Returns a stream of match results from this scanner. |
String
|
findInLine(String pattern)
Attempts to find the next occurrence of a pattern constructed from the specified string, ignoring delimiters. |
String
|
findInLine(Pattern pattern)
Attempts to find the next occurrence of the specified pattern ignoring delimiters. |
String
|
findWithinHorizon(Pattern pattern, int horizon)
Attempts to find the next occurrence of the specified pattern. |
String
|
findWithinHorizon(String pattern, int horizon)
Attempts to find the next occurrence of a pattern constructed from the specified string, ignoring delimiters. |
boolean
|
hasNext()
Returns true if this scanner has another token in its input. |
boolean
|
hasNext(String pattern)
Returns true if the next token matches the pattern constructed from the specified string. |
boolean
|
hasNext(Pattern pattern)
Returns true if the next complete token matches the specified pattern. |
boolean
|
hasNextBigDecimal()
Returns true if the next token in this scanner's input can be
interpreted as a |
boolean
|
hasNextBigInteger(int radix)
Returns true if the next token in this scanner's input can be
interpreted as a |
boolean
|
hasNextBigInteger()
Returns true if the next token in this scanner's input can be
interpreted as a |
boolean
|
hasNextBoolean()
Returns true if the next token in this scanner's input can be interpreted as a boolean value using a case insensitive pattern created from the string "true|false". |
boolean
|
hasNextByte()
Returns true if the next token in this scanner's input can be
interpreted as a byte value in the default radix using the
|
boolean
|
hasNextByte(int radix)
Returns true if the next token in this scanner's input can be
interpreted as a byte value in the specified radix using the
|
boolean
|
hasNextDouble()
Returns true if the next token in this scanner's input can be
interpreted as a double value using the |
boolean
|
hasNextFloat()
Returns true if the next token in this scanner's input can be
interpreted as a float value using the |
boolean
|
hasNextInt()
Returns true if the next token in this scanner's input can be
interpreted as an int value in the default radix using the
|
boolean
|
hasNextInt(int radix)
Returns true if the next token in this scanner's input can be
interpreted as an int value in the specified radix using the
|
boolean
|
hasNextLine()
Returns true if there is another line in the input of this scanner. |
boolean
|
hasNextLong()
Returns true if the next token in this scanner's input can be
interpreted as a long value in the default radix using the
|
boolean
|
hasNextLong(int radix)
Returns true if the next token in this scanner's input can be
interpreted as a long value in the specified radix using the
|
boolean
|
hasNextShort()
Returns true if the next token in this scanner's input can be
interpreted as a short value in the default radix using the
|
boolean
|
hasNextShort(int radix)
Returns true if the next token in this scanner's input can be
interpreted as a short value in the specified radix using the
|
IOException
|
ioException()
Returns the |
Locale
|
locale()
Returns this scanner's locale. |
MatchResult
|
match()
Returns the match result of the last scanning operation performed by this scanner. |
String
|
next(Pattern pattern)
Returns the next token if it matches the specified pattern. |
String
|
next()
Finds and returns the next complete token from this scanner. |
String
|
next(String pattern)
Returns the next token if it matches the pattern constructed from the specified string. |
BigDecimal
|
nextBigDecimal()
Scans the next token of the input as a |
BigInteger
|
nextBigInteger()
Scans the next token of the input as a |
BigInteger
|
nextBigInteger(int radix)
Scans the next token of the input as a |
boolean
|
nextBoolean()
Scans the next token of the input into a boolean value and returns that value. |
byte
|
nextByte(int radix)
Scans the next token of the input as a |
byte
|
nextByte()
Scans the next token of the input as a |
double
|
nextDouble()
Scans the next token of the input as a |
float
|
nextFloat()
Scans the next token of the input as a |
int
|
nextInt()
Scans the next token of the input as an |
int
|
nextInt(int radix)
Scans the next token of the input as an |
String
|
nextLine()
Advances this scanner past the current line and returns the input that was skipped. |
long
|
nextLong()
Scans the next token of the input as a |
long
|
nextLong(int radix)
Scans the next token of the input as a |
short
|
nextShort(int radix)
Scans the next token of the input as a |
short
|
nextShort()
Scans the next token of the input as a |
int
|
radix()
Returns this scanner's default radix. |
void
|
remove()
The remove operation is not supported by this implementation of
|
Scanner
|
reset()
Resets this scanner. |
Scanner
|
skip(String pattern)
Skips input that matches a pattern constructed from the specified string. |
Scanner
|
skip(Pattern pattern)
Skips input that matches the specified pattern, ignoring delimiters. |
String
|
toString()
Returns the string representation of this |
Stream<String>
|
tokens()
Returns a stream of delimiter-separated tokens from this scanner. |
Scanner
|
useDelimiter(Pattern pattern)
Sets this scanner's delimiting pattern to the specified pattern. |
Scanner
|
useDelimiter(String pattern)
Sets this scanner's delimiting pattern to a pattern constructed from
the specified |
Scanner
|
useLocale(Locale locale)
Sets this scanner's locale to the specified locale. |
Scanner
|
useRadix(int radix)
Sets this scanner's default radix to the specified radix. |
Inherited methods | |
---|---|
Public constructors
Scanner
public Scanner (File source)
Constructs a new Scanner
that produces values scanned
from the specified file. Bytes from the file are converted into
characters using the underlying platform's
default charset.
Parameters | |
---|---|
source |
File : A file to be scanned |
Throws | |
---|---|
FileNotFoundException |
if source is not found |
Scanner
public Scanner (File source, String charsetName)
Constructs a new Scanner
that produces values scanned
from the specified file. Bytes from the file are converted into
characters using the specified charset.
Parameters | |
---|---|
source |
File : A file to be scanned |
charsetName |
String : The encoding type used to convert bytes from the file
into characters to be scanned |
Throws | |
---|---|
FileNotFoundException |
if source is not found |
IllegalArgumentException |
if the specified encoding is not found |
Scanner
public Scanner (File source, Charset charset)
Constructs a new Scanner
that produces values scanned
from the specified file. Bytes from the file are converted into
characters using the specified charset.
Parameters | |
---|---|
source |
File : A file to be scanned |
charset |
Charset : The charset used to convert bytes from the file
into characters to be scanned |
Throws | |
---|---|
IOException |
if an I/O error occurs opening the source |
Scanner
public Scanner (InputStream source)
Constructs a new Scanner
that produces values scanned
from the specified input stream. Bytes from the stream are converted
into characters using the underlying platform's
default charset.
Parameters | |
---|---|
source |
InputStream : An input stream to be scanned |
Scanner
public Scanner (InputStream source, String charsetName)
Constructs a new Scanner
that produces values scanned
from the specified input stream. Bytes from the stream are converted
into characters using the specified charset.
Parameters | |
---|---|
source |
InputStream : An input stream to be scanned |
charsetName |
String : The encoding type used to convert bytes from the
stream into characters to be scanned |
Throws | |
---|---|
IllegalArgumentException |
if the specified character set does not exist |
Scanner
public Scanner (InputStream source, Charset charset)
Constructs a new Scanner
that produces values scanned
from the specified input stream. Bytes from the stream are converted
into characters using the specified charset.
Parameters | |
---|---|
source |
InputStream : an input stream to be scanned |
charset |
Charset : the charset used to convert bytes from the file
into characters to be scanned |
Scanner
public Scanner (Readable source)
Constructs a new Scanner
that produces values scanned
from the specified source.
Parameters | |
---|---|
source |
Readable : A character source implementing the Readable
interface |
Scanner
public Scanner (String source)
Constructs a new Scanner
that produces values scanned
from the specified string.
Parameters | |
---|---|
source |
String : A string to scan |
Scanner
public Scanner (ReadableByteChannel source)
Constructs a new Scanner
that produces values scanned
from the specified channel. Bytes from the source are converted into
characters using the underlying platform's
default charset.
Parameters | |
---|---|
source |
ReadableByteChannel : A channel to scan |
Scanner
public Scanner (ReadableByteChannel source, String charsetName)
Constructs a new Scanner
that produces values scanned
from the specified channel. Bytes from the source are converted into
characters using the specified charset.
Parameters | |
---|---|
source |
ReadableByteChannel : A channel to scan |
charsetName |
String : The encoding type used to convert bytes from the
channel into characters to be scanned |
Throws | |
---|---|
IllegalArgumentException |
if the specified character set does not exist |
Scanner
public Scanner (ReadableByteChannel source, Charset charset)
Constructs a new Scanner
that produces values scanned
from the specified channel. Bytes from the source are converted into
characters using the specified charset.
Parameters | |
---|---|
source |
ReadableByteChannel : a channel to scan |
charset |
Charset : the encoding type used to convert bytes from the
channel into characters to be scanned |
Scanner
public Scanner (Path source)
Constructs a new Scanner
that produces values scanned
from the specified file. Bytes from the file are converted into
characters using the underlying platform's
default charset.
Parameters | |
---|---|
source |
Path : the path to the file to be scanned |
Throws | |
---|---|
IOException |
if an I/O error occurs opening source |
Scanner
public Scanner (Path source, String charsetName)
Constructs a new Scanner
that produces values scanned
from the specified file. Bytes from the file are converted into
characters using the specified charset.
Parameters | |
---|---|
source |
Path : the path to the file to be scanned |
charsetName |
String : The encoding type used to convert bytes from the file
into characters to be scanned |
Throws | |
---|---|
IOException |
if an I/O error occurs opening source |
IllegalArgumentException |
if the specified encoding is not found |
Scanner
public Scanner (Path source, Charset charset)
Constructs a new Scanner
that produces values scanned
from the specified file. Bytes from the file are converted into
characters using the specified charset.
Parameters | |
---|---|
source |
Path : the path to the file to be scanned |
charset |
Charset : the charset used to convert bytes from the file
into characters to be scanned |
Throws | |
---|---|
IOException |
if an I/O error occurs opening the source |
Public methods
close
public void close ()
Closes this scanner.
If this scanner has not yet been closed then if its underlying
readable also implements the Closeable
interface then the readable's close
method
will be invoked. If this scanner is already closed then invoking this
method will have no effect.
Attempting to perform search operations after a scanner has
been closed will result in an IllegalStateException
.
delimiter
public Pattern delimiter ()
Returns the Pattern
this Scanner
is currently
using to match delimiters.
Returns | |
---|---|
Pattern |
this scanner's delimiting pattern. |
findAll
public Stream<MatchResult> findAll (String patString)
Returns a stream of match results that match the provided pattern string. The effect is equivalent to the following code:
scanner.findAll(Pattern.compile(patString))
Parameters | |
---|---|
patString |
String : the pattern string |
Returns | |
---|---|
Stream<MatchResult> |
a sequential stream of match results |
Throws | |
---|---|
NullPointerException |
if patString is null |
IllegalStateException |
if this scanner is closed |
PatternSyntaxException |
if the regular expression's syntax is invalid |
See also:
findAll
public Stream<MatchResult> findAll (Pattern pattern)
Returns a stream of match results from this scanner. The stream
contains the same results in the same order that would be returned by
calling findWithinHorizon(pattern, 0)
and then match()
successively as long as findWithinHorizon()
finds matches.
The resulting stream is sequential and ordered. All stream elements are non-null.
Scanning starts upon initiation of the terminal stream operation, using the
current state of this scanner. Subsequent calls to any methods on this scanner
other than close()
and ioException()
may return undefined results
or may cause undefined effects on the returned stream. The returned stream's source
Spliterator
is fail-fast and will, on a best-effort basis, throw a
ConcurrentModificationException
if any such calls are detected
during stream pipeline execution.
After stream pipeline execution completes, this scanner is left in an indeterminate state and cannot be reused.
If this scanner contains a resource that must be released, this scanner
should be closed, either by calling its close()
method, or by
closing the returned stream. Closing the stream will close the underlying scanner.
IllegalStateException
is thrown if the scanner has been closed when this
method is called, or if this scanner is closed during stream pipeline execution.
As with the findWithinHorizon()
methods, this method
might block waiting for additional input, and it might buffer an unbounded amount of
input searching for a match.
API Note:
- For example, the following code will read a file and return a list
of all sequences of characters consisting of seven or more Latin capital
letters:
try (Scanner sc = new Scanner(Path.of("input.txt"))) { Pattern pat = Pattern.compile("[A-Z]{7,}"); List<String> capWords = sc.findAll(pat) .map(MatchResult::group) .collect(Collectors.toList()); }
Parameters | |
---|---|
pattern |
Pattern : the pattern to be matched |
Returns | |
---|---|
Stream<MatchResult> |
a sequential stream of match results |
Throws | |
---|---|
NullPointerException |
if pattern is null |
IllegalStateException |
if this scanner is closed |
findInLine
public String findInLine (String pattern)
Attempts to find the next occurrence of a pattern constructed from the specified string, ignoring delimiters.
An invocation of this method of the form findInLine(pattern)
behaves in exactly the same way as the invocation
findInLine(Pattern.compile(pattern))
.
Parameters | |
---|---|
pattern |
String : a string specifying the pattern to search for |
Returns | |
---|---|
String |
the text that matched the specified pattern |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
findInLine
public String findInLine (Pattern pattern)
Attempts to find the next occurrence of the specified pattern ignoring
delimiters. If the pattern is found before the next line separator, the
scanner advances past the input that matched and returns the string that
matched the pattern.
If no such pattern is detected in the input up to the next line
separator, then null
is returned and the scanner's
position is unchanged. This method may block waiting for input that
matches the pattern.
Since this method continues to search through the input looking for the specified pattern, it may buffer all of the input searching for the desired token if no line separators are present.
Parameters | |
---|---|
pattern |
Pattern : the pattern to scan for |
Returns | |
---|---|
String |
the text that matched the specified pattern |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
findWithinHorizon
public String findWithinHorizon (Pattern pattern, int horizon)
Attempts to find the next occurrence of the specified pattern.
This method searches through the input up to the specified search horizon, ignoring delimiters. If the pattern is found the scanner advances past the input that matched and returns the string that matched the pattern. If no such pattern is detected then the null is returned and the scanner's position remains unchanged. This method may block waiting for input that matches the pattern.
A scanner will never search more than horizon
code
points beyond its current position. Note that a match may be clipped
by the horizon; that is, an arbitrary match result may have been
different if the horizon had been larger. The scanner treats the
horizon as a transparent, non-anchoring bound (see Matcher.useTransparentBounds(boolean)
and Matcher.useAnchoringBounds
).
If horizon is 0
, then the horizon is ignored and
this method continues to search through the input looking for the
specified pattern without bound. In this case it may buffer all of
the input searching for the pattern.
If horizon is negative, then an IllegalArgumentException is thrown.
Parameters | |
---|---|
pattern |
Pattern : the pattern to scan for |
horizon |
int : the search horizon |
Returns | |
---|---|
String |
the text that matched the specified pattern |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
IllegalArgumentException |
if horizon is negative |
findWithinHorizon
public String findWithinHorizon (String pattern, int horizon)
Attempts to find the next occurrence of a pattern constructed from the specified string, ignoring delimiters.
An invocation of this method of the form
findWithinHorizon(pattern)
behaves in exactly the same way as
the invocation
findWithinHorizon(Pattern.compile(pattern), horizon)
.
Parameters | |
---|---|
pattern |
String : a string specifying the pattern to search for |
horizon |
int : the search horizon |
Returns | |
---|---|
String |
the text that matched the specified pattern |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
IllegalArgumentException |
if horizon is negative |
hasNext
public boolean hasNext ()
Returns true if this scanner has another token in its input. This method may block while waiting for input to scan. The scanner does not advance past any input.
Returns | |
---|---|
boolean |
true if and only if this scanner has another token |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
See also:
hasNext
public boolean hasNext (String pattern)
Returns true if the next token matches the pattern constructed from the specified string. The scanner does not advance past any input.
An invocation of this method of the form hasNext(pattern)
behaves in exactly the same way as the invocation
hasNext(Pattern.compile(pattern))
.
Parameters | |
---|---|
pattern |
String : a string specifying the pattern to scan |
Returns | |
---|---|
boolean |
true if and only if this scanner has another token matching the specified pattern |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
hasNext
public boolean hasNext (Pattern pattern)
Returns true if the next complete token matches the specified pattern. A complete token is prefixed and postfixed by input that matches the delimiter pattern. This method may block while waiting for input. The scanner does not advance past any input.
Parameters | |
---|---|
pattern |
Pattern : the pattern to scan for |
Returns | |
---|---|
boolean |
true if and only if this scanner has another token matching the specified pattern |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
hasNextBigDecimal
public boolean hasNextBigDecimal ()
Returns true if the next token in this scanner's input can be
interpreted as a BigDecimal
using the
nextBigDecimal()
method. The scanner does not advance past any
input.
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid
BigDecimal |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
hasNextBigInteger
public boolean hasNextBigInteger (int radix)
Returns true if the next token in this scanner's input can be
interpreted as a BigInteger
in the specified radix using
the nextBigInteger()
method. The scanner does not advance past
any input.
If the radix is less than Character.MIN_RADIX
or greater than Character.MAX_RADIX
, then an
IllegalArgumentException
is thrown.
Parameters | |
---|---|
radix |
int : the radix used to interpret the token as an integer |
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid
BigInteger |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
IllegalArgumentException |
if the radix is out of range |
hasNextBigInteger
public boolean hasNextBigInteger ()
Returns true if the next token in this scanner's input can be
interpreted as a BigInteger
in the default radix using the
nextBigInteger()
method. The scanner does not advance past any
input.
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid
BigInteger |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
hasNextBoolean
public boolean hasNextBoolean ()
Returns true if the next token in this scanner's input can be interpreted as a boolean value using a case insensitive pattern created from the string "true|false". The scanner does not advance past the input that matched.
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid boolean value |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
hasNextByte
public boolean hasNextByte ()
Returns true if the next token in this scanner's input can be
interpreted as a byte value in the default radix using the
nextByte()
method. The scanner does not advance past any input.
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid byte value |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
hasNextByte
public boolean hasNextByte (int radix)
Returns true if the next token in this scanner's input can be
interpreted as a byte value in the specified radix using the
nextByte()
method. The scanner does not advance past any input.
If the radix is less than Character.MIN_RADIX
or greater than Character.MAX_RADIX
, then an
IllegalArgumentException
is thrown.
Parameters | |
---|---|
radix |
int : the radix used to interpret the token as a byte value |
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid byte value |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
IllegalArgumentException |
if the radix is out of range |
hasNextDouble
public boolean hasNextDouble ()
Returns true if the next token in this scanner's input can be
interpreted as a double value using the nextDouble()
method. The scanner does not advance past any input.
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid double value |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
hasNextFloat
public boolean hasNextFloat ()
Returns true if the next token in this scanner's input can be
interpreted as a float value using the nextFloat()
method. The scanner does not advance past any input.
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid float value |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
hasNextInt
public boolean hasNextInt ()
Returns true if the next token in this scanner's input can be
interpreted as an int value in the default radix using the
nextInt()
method. The scanner does not advance past any input.
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid int value |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
hasNextInt
public boolean hasNextInt (int radix)
Returns true if the next token in this scanner's input can be
interpreted as an int value in the specified radix using the
nextInt()
method. The scanner does not advance past any input.
If the radix is less than Character.MIN_RADIX
or greater than Character.MAX_RADIX
, then an
IllegalArgumentException
is thrown.
Parameters | |
---|---|
radix |
int : the radix used to interpret the token as an int value |
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid int value |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
IllegalArgumentException |
if the radix is out of range |
hasNextLine
public boolean hasNextLine ()
Returns true if there is another line in the input of this scanner. This method may block while waiting for input. The scanner does not advance past any input.
Returns | |
---|---|
boolean |
true if and only if this scanner has another line of input |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
hasNextLong
public boolean hasNextLong ()
Returns true if the next token in this scanner's input can be
interpreted as a long value in the default radix using the
nextLong()
method. The scanner does not advance past any input.
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid long value |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
hasNextLong
public boolean hasNextLong (int radix)
Returns true if the next token in this scanner's input can be
interpreted as a long value in the specified radix using the
nextLong()
method. The scanner does not advance past any input.
If the radix is less than Character.MIN_RADIX
or greater than Character.MAX_RADIX
, then an
IllegalArgumentException
is thrown.
Parameters | |
---|---|
radix |
int : the radix used to interpret the token as a long value |
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid long value |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
IllegalArgumentException |
if the radix is out of range |
hasNextShort
public boolean hasNextShort ()
Returns true if the next token in this scanner's input can be
interpreted as a short value in the default radix using the
nextShort()
method. The scanner does not advance past any input.
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid short value in the default radix |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
hasNextShort
public boolean hasNextShort (int radix)
Returns true if the next token in this scanner's input can be
interpreted as a short value in the specified radix using the
nextShort()
method. The scanner does not advance past any input.
If the radix is less than Character.MIN_RADIX
or greater than Character.MAX_RADIX
, then an
IllegalArgumentException
is thrown.
Parameters | |
---|---|
radix |
int : the radix used to interpret the token as a short value |
Returns | |
---|---|
boolean |
true if and only if this scanner's next token is a valid short value in the specified radix |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
IllegalArgumentException |
if the radix is out of range |
ioException
public IOException ioException ()
Returns the IOException
last thrown by this
Scanner
's underlying Readable
. This method
returns null
if no such exception exists.
Returns | |
---|---|
IOException |
the last exception thrown by this scanner's readable |
locale
public Locale locale ()
Returns this scanner's locale.
A scanner's locale affects many elements of its default primitive matching regular expressions; see localized numbers above.
Returns | |
---|---|
Locale |
this scanner's locale |
match
public MatchResult match ()
Returns the match result of the last scanning operation performed
by this scanner. This method throws IllegalStateException
if no match has been performed, or if the last match was
not successful.
The various next
methods of Scanner
make a match result available if they complete without throwing an
exception. For instance, after an invocation of the nextInt()
method that returned an int, this method returns a
MatchResult
for the search of the
Integer regular expression
defined above. Similarly the findInLine()
,
findWithinHorizon()
, and skip()
methods will make a match available if they succeed.
Returns | |
---|---|
MatchResult |
a match result for the last match operation |
Throws | |
---|---|
IllegalStateException |
If no match result is available |
next
public String next (Pattern pattern)
Returns the next token if it matches the specified pattern. This
method may block while waiting for input to scan, even if a previous
invocation of hasNext(java.util.regex.Pattern)
returned true
.
If the match is successful, the scanner advances past the input that
matched the pattern.
Parameters | |
---|---|
pattern |
Pattern : the pattern to scan for |
Returns | |
---|---|
String |
the next token |
Throws | |
---|---|
NoSuchElementException |
if no more tokens are available |
IllegalStateException |
if this scanner is closed |
next
public String next ()
Finds and returns the next complete token from this scanner.
A complete token is preceded and followed by input that matches
the delimiter pattern. This method may block while waiting for input
to scan, even if a previous invocation of hasNext()
returned
true
.
Returns | |
---|---|
String |
the next token |
Throws | |
---|---|
NoSuchElementException |
if no more tokens are available |
IllegalStateException |
if this scanner is closed |
See also:
next
public String next (String pattern)
Returns the next token if it matches the pattern constructed from the specified string. If the match is successful, the scanner advances past the input that matched the pattern.
An invocation of this method of the form next(pattern)
behaves in exactly the same way as the invocation
next(Pattern.compile(pattern))
.
Parameters | |
---|---|
pattern |
String : a string specifying the pattern to scan |
Returns | |
---|---|
String |
the next token |
Throws | |
---|---|
NoSuchElementException |
if no such tokens are available |
IllegalStateException |
if this scanner is closed |
nextBigDecimal
public BigDecimal nextBigDecimal ()
Scans the next token of the input as a BigDecimal
.
If the next token matches the Decimal regular expression defined
above then the token is converted into a BigDecimal
value as if
by removing all group separators, mapping non-ASCII digits into ASCII
digits via the Character.digit
, and passing the
resulting string to the BigDecimal(String)
constructor.
Returns | |
---|---|
BigDecimal |
the BigDecimal scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token does not match the Decimal regular expression, or is out of range |
NoSuchElementException |
if the input is exhausted |
IllegalStateException |
if this scanner is closed |
nextBigInteger
public BigInteger nextBigInteger ()
Scans the next token of the input as a BigInteger
.
An invocation of this method of the form
nextBigInteger()
behaves in exactly the same way as the
invocation nextBigInteger(radix)
, where radix
is the default radix of this scanner.
Returns | |
---|---|
BigInteger |
the BigInteger scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token does not match the Integer regular expression, or is out of range |
NoSuchElementException |
if the input is exhausted |
IllegalStateException |
if this scanner is closed |
nextBigInteger
public BigInteger nextBigInteger (int radix)
Scans the next token of the input as a BigInteger
.
If the next token matches the Integer regular expression defined
above then the token is converted into a BigInteger
value as if
by removing all group separators, mapping non-ASCII digits into ASCII
digits via the Character.digit
, and passing the
resulting string to the BigInteger(String, int)
constructor with the specified radix.
If the radix is less than Character.MIN_RADIX
or greater than Character.MAX_RADIX
, then an
IllegalArgumentException
is thrown.
Parameters | |
---|---|
radix |
int : the radix used to interpret the token |
Returns | |
---|---|
BigInteger |
the BigInteger scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token does not match the Integer regular expression, or is out of range |
NoSuchElementException |
if the input is exhausted |
IllegalStateException |
if this scanner is closed |
IllegalArgumentException |
if the radix is out of range |
nextBoolean
public boolean nextBoolean ()
Scans the next token of the input into a boolean value and returns
that value. This method will throw InputMismatchException
if the next token cannot be translated into a valid boolean value.
If the match is successful, the scanner advances past the input that
matched.
Returns | |
---|---|
boolean |
the boolean scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token is not a valid boolean |
NoSuchElementException |
if input is exhausted |
IllegalStateException |
if this scanner is closed |
nextByte
public byte nextByte (int radix)
Scans the next token of the input as a byte
.
This method will throw InputMismatchException
if the next token cannot be translated into a valid byte value as
described below. If the translation is successful, the scanner advances
past the input that matched.
If the next token matches the Integer regular expression defined
above then the token is converted into a byte
value as if by
removing all locale specific prefixes, group separators, and locale
specific suffixes, then mapping non-ASCII digits into ASCII
digits via Character.digit
, prepending a
negative sign (-) if the locale specific negative prefixes and suffixes
were present, and passing the resulting string to
Byte.parseByte
with the
specified radix.
If the radix is less than Character.MIN_RADIX
or greater than Character.MAX_RADIX
, then an
IllegalArgumentException
is thrown.
Parameters | |
---|---|
radix |
int : the radix used to interpret the token as a byte value |
Returns | |
---|---|
byte |
the byte scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token does not match the Integer regular expression, or is out of range |
NoSuchElementException |
if input is exhausted |
IllegalStateException |
if this scanner is closed |
IllegalArgumentException |
if the radix is out of range |
nextByte
public byte nextByte ()
Scans the next token of the input as a byte
.
An invocation of this method of the form
nextByte()
behaves in exactly the same way as the
invocation nextByte(radix)
, where radix
is the default radix of this scanner.
Returns | |
---|---|
byte |
the byte scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token does not match the Integer regular expression, or is out of range |
NoSuchElementException |
if input is exhausted |
IllegalStateException |
if this scanner is closed |
nextDouble
public double nextDouble ()
Scans the next token of the input as a double
.
This method will throw InputMismatchException
if the next token cannot be translated into a valid double value.
If the translation is successful, the scanner advances past the input
that matched.
If the next token matches the Float regular expression defined above
then the token is converted into a double
value as if by
removing all locale specific prefixes, group separators, and locale
specific suffixes, then mapping non-ASCII digits into ASCII
digits via Character.digit
, prepending a
negative sign (-) if the locale specific negative prefixes and suffixes
were present, and passing the resulting string to
Double.parseDouble
. If the token matches
the localized NaN or infinity strings, then either "Nan" or "Infinity"
is passed to Double.parseDouble
as
appropriate.
Returns | |
---|---|
double |
the double scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token does not match the Float regular expression, or is out of range |
NoSuchElementException |
if the input is exhausted |
IllegalStateException |
if this scanner is closed |
nextFloat
public float nextFloat ()
Scans the next token of the input as a float
.
This method will throw InputMismatchException
if the next token cannot be translated into a valid float value as
described below. If the translation is successful, the scanner advances
past the input that matched.
If the next token matches the Float regular expression defined above
then the token is converted into a float
value as if by
removing all locale specific prefixes, group separators, and locale
specific suffixes, then mapping non-ASCII digits into ASCII
digits via Character.digit
, prepending a
negative sign (-) if the locale specific negative prefixes and suffixes
were present, and passing the resulting string to
Float.parseFloat
. If the token matches
the localized NaN or infinity strings, then either "Nan" or "Infinity"
is passed to Float.parseFloat
as
appropriate.
Returns | |
---|---|
float |
the float scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token does not match the Float regular expression, or is out of range |
NoSuchElementException |
if input is exhausted |
IllegalStateException |
if this scanner is closed |
nextInt
public int nextInt ()
Scans the next token of the input as an int
.
An invocation of this method of the form
nextInt()
behaves in exactly the same way as the
invocation nextInt(radix)
, where radix
is the default radix of this scanner.
Returns | |
---|---|
int |
the int scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token does not match the Integer regular expression, or is out of range |
NoSuchElementException |
if input is exhausted |
IllegalStateException |
if this scanner is closed |
nextInt
public int nextInt (int radix)
Scans the next token of the input as an int
.
This method will throw InputMismatchException
if the next token cannot be translated into a valid int value as
described below. If the translation is successful, the scanner advances
past the input that matched.
If the next token matches the Integer regular expression defined
above then the token is converted into an int
value as if by
removing all locale specific prefixes, group separators, and locale
specific suffixes, then mapping non-ASCII digits into ASCII
digits via Character.digit
, prepending a
negative sign (-) if the locale specific negative prefixes and suffixes
were present, and passing the resulting string to
Integer.parseInt
with the
specified radix.
If the radix is less than Character.MIN_RADIX
or greater than Character.MAX_RADIX
, then an
IllegalArgumentException
is thrown.
Parameters | |
---|---|
radix |
int : the radix used to interpret the token as an int value |
Returns | |
---|---|
int |
the int scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token does not match the Integer regular expression, or is out of range |
NoSuchElementException |
if input is exhausted |
IllegalStateException |
if this scanner is closed |
IllegalArgumentException |
if the radix is out of range |
nextLine
public String nextLine ()
Advances this scanner past the current line and returns the input that was skipped. This method returns the rest of the current line, excluding any line separator at the end. The position is set to the beginning of the next line.
Since this method continues to search through the input looking for a line separator, it may buffer all of the input searching for the line to skip if no line separators are present.
Returns | |
---|---|
String |
the line that was skipped |
Throws | |
---|---|
NoSuchElementException |
if no line was found |
IllegalStateException |
if this scanner is closed |
nextLong
public long nextLong ()
Scans the next token of the input as a long
.
An invocation of this method of the form
nextLong()
behaves in exactly the same way as the
invocation nextLong(radix)
, where radix
is the default radix of this scanner.
Returns | |
---|---|
long |
the long scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token does not match the Integer regular expression, or is out of range |
NoSuchElementException |
if input is exhausted |
IllegalStateException |
if this scanner is closed |
nextLong
public long nextLong (int radix)
Scans the next token of the input as a long
.
This method will throw InputMismatchException
if the next token cannot be translated into a valid long value as
described below. If the translation is successful, the scanner advances
past the input that matched.
If the next token matches the Integer regular expression defined
above then the token is converted into a long
value as if by
removing all locale specific prefixes, group separators, and locale
specific suffixes, then mapping non-ASCII digits into ASCII
digits via Character.digit
, prepending a
negative sign (-) if the locale specific negative prefixes and suffixes
were present, and passing the resulting string to
Long.parseLong
with the
specified radix.
If the radix is less than Character.MIN_RADIX
or greater than Character.MAX_RADIX
, then an
IllegalArgumentException
is thrown.
Parameters | |
---|---|
radix |
int : the radix used to interpret the token as an int value |
Returns | |
---|---|
long |
the long scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token does not match the Integer regular expression, or is out of range |
NoSuchElementException |
if input is exhausted |
IllegalStateException |
if this scanner is closed |
IllegalArgumentException |
if the radix is out of range |
nextShort
public short nextShort (int radix)
Scans the next token of the input as a short
.
This method will throw InputMismatchException
if the next token cannot be translated into a valid short value as
described below. If the translation is successful, the scanner advances
past the input that matched.
If the next token matches the Integer regular expression defined
above then the token is converted into a short
value as if by
removing all locale specific prefixes, group separators, and locale
specific suffixes, then mapping non-ASCII digits into ASCII
digits via Character.digit
, prepending a
negative sign (-) if the locale specific negative prefixes and suffixes
were present, and passing the resulting string to
Short.parseShort
with the
specified radix.
If the radix is less than Character.MIN_RADIX
or greater than Character.MAX_RADIX
, then an
IllegalArgumentException
is thrown.
Parameters | |
---|---|
radix |
int : the radix used to interpret the token as a short value |
Returns | |
---|---|
short |
the short scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token does not match the Integer regular expression, or is out of range |
NoSuchElementException |
if input is exhausted |
IllegalStateException |
if this scanner is closed |
IllegalArgumentException |
if the radix is out of range |
nextShort
public short nextShort ()
Scans the next token of the input as a short
.
An invocation of this method of the form
nextShort()
behaves in exactly the same way as the
invocation nextShort(radix)
, where radix
is the default radix of this scanner.
Returns | |
---|---|
short |
the short scanned from the input |
Throws | |
---|---|
InputMismatchException |
if the next token does not match the Integer regular expression, or is out of range |
NoSuchElementException |
if input is exhausted |
IllegalStateException |
if this scanner is closed |
radix
public int radix ()
Returns this scanner's default radix.
A scanner's radix affects elements of its default number matching regular expressions; see localized numbers above.
Returns | |
---|---|
int |
the default radix of this scanner |
remove
public void remove ()
The remove operation is not supported by this implementation of
Iterator
.
Throws | |
---|---|
UnsupportedOperationException |
if this method is invoked. |
See also:
reset
public Scanner reset ()
Resets this scanner.
Resetting a scanner discards all of its explicit state
information which may have been changed by invocations of
useDelimiter()
,
useLocale()
, or
useRadix()
.
An invocation of this method of the form
scanner.reset()
behaves in exactly the same way as the
invocation
scanner.useDelimiter("\\p{javaWhitespace}+") .useLocale(Locale.getDefault(Locale.Category.FORMAT)) .useRadix(10);
Returns | |
---|---|
Scanner |
this scanner |
skip
public Scanner skip (String pattern)
Skips input that matches a pattern constructed from the specified string.
An invocation of this method of the form skip(pattern)
behaves in exactly the same way as the invocation
skip(Pattern.compile(pattern))
.
Parameters | |
---|---|
pattern |
String : a string specifying the pattern to skip over |
Returns | |
---|---|
Scanner |
this scanner |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
skip
public Scanner skip (Pattern pattern)
Skips input that matches the specified pattern, ignoring delimiters. This method will skip input if an anchored match of the specified pattern succeeds.
If a match to the specified pattern is not found at the
current position, then no input is skipped and a
NoSuchElementException
is thrown.
Since this method seeks to match the specified pattern starting at the scanner's current position, patterns that can match a lot of input (".*", for example) may cause the scanner to buffer a large amount of input.
Note that it is possible to skip something without risking a
NoSuchElementException
by using a pattern that can
match nothing, e.g., sc.skip("[ \t]*")
.
Parameters | |
---|---|
pattern |
Pattern : a string specifying the pattern to skip over |
Returns | |
---|---|
Scanner |
this scanner |
Throws | |
---|---|
NoSuchElementException |
if the specified pattern is not found |
IllegalStateException |
if this scanner is closed |
toString
public String toString ()
Returns the string representation of this Scanner
. The
string representation of a Scanner
contains information
that may be useful for debugging. The exact format is unspecified.
Returns | |
---|---|
String |
The string representation of this scanner |
tokens
public Stream<String> tokens ()
Returns a stream of delimiter-separated tokens from this scanner. The
stream contains the same tokens that would be returned, starting from
this scanner's current state, by calling the next()
method
repeatedly until the hasNext()
method returns false.
The resulting stream is sequential and ordered. All stream elements are non-null.
Scanning starts upon initiation of the terminal stream operation, using the
current state of this scanner. Subsequent calls to any methods on this scanner
other than close()
and ioException()
may return undefined results
or may cause undefined effects on the returned stream. The returned stream's source
Spliterator
is fail-fast and will, on a best-effort basis, throw a
ConcurrentModificationException
if any such calls are detected
during stream pipeline execution.
After stream pipeline execution completes, this scanner is left in an indeterminate state and cannot be reused.
If this scanner contains a resource that must be released, this scanner
should be closed, either by calling its close()
method, or by
closing the returned stream. Closing the stream will close the underlying scanner.
IllegalStateException
is thrown if the scanner has been closed when this
method is called, or if this scanner is closed during stream pipeline execution.
This method might block waiting for more input.
API Note:
- For example, the following code will create a list of
comma-delimited tokens from a string:
List<String> result = new Scanner("abc,def,,ghi") .useDelimiter(",") .tokens() .collect(Collectors.toList());
The resulting list would contain
"abc"
,"def"
, the empty string, and"ghi"
.
Returns | |
---|---|
Stream<String> |
a sequential stream of token strings |
Throws | |
---|---|
IllegalStateException |
if this scanner is closed |
useDelimiter
public Scanner useDelimiter (Pattern pattern)
Sets this scanner's delimiting pattern to the specified pattern.
Parameters | |
---|---|
pattern |
Pattern : A delimiting pattern |
Returns | |
---|---|
Scanner |
this scanner |
useDelimiter
public Scanner useDelimiter (String pattern)
Sets this scanner's delimiting pattern to a pattern constructed from
the specified String
.
An invocation of this method of the form
useDelimiter(pattern)
behaves in exactly the same way as the
invocation useDelimiter(Pattern.compile(pattern))
.
Invoking the reset()
method will set the scanner's delimiter
to the default.
Parameters | |
---|---|
pattern |
String : A string specifying a delimiting pattern |
Returns | |
---|---|
Scanner |
this scanner |
useLocale
public Scanner useLocale (Locale locale)
Sets this scanner's locale to the specified locale.
A scanner's locale affects many elements of its default primitive matching regular expressions; see localized numbers above.
Invoking the reset()
method will set the scanner's locale to
the initial locale.
Parameters | |
---|---|
locale |
Locale : A string specifying the locale to use |
Returns | |
---|---|
Scanner |
this scanner |
useRadix
public Scanner useRadix (int radix)
Sets this scanner's default radix to the specified radix.
A scanner's radix affects elements of its default number matching regular expressions; see localized numbers above.
If the radix is less than Character.MIN_RADIX
or greater than Character.MAX_RADIX
, then an
IllegalArgumentException
is thrown.
Invoking the reset()
method will set the scanner's radix to
10
.
Parameters | |
---|---|
radix |
int : The radix to use when scanning numbers |
Returns | |
---|---|
Scanner |
this scanner |
Throws | |
---|---|
IllegalArgumentException |
if radix is out of range |