| |
|
| java.lang.Object
 java.util.Scanner
| Scanner | | final public class Scanner implements Iterator<String>(Code) | | 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
java.lang.Character .
java.lang.Character.isWhitespace(char) isWhitespace . The
Scanner.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
Scanner.next and
Scanner.hasNext methods and their
primitive-type companion methods (such as
Scanner.nextInt and
Scanner.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
Scanner.findInLine ,
Scanner.findWithinHorizon , and
Scanner.skip 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
java.lang.Readable interface. If an invocation of the underlying
readable's
java.lang.Readable.read method throws an
java.io.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
Scanner.ioException method.
When a Scanner is closed, it will close its input source
if the source implements the
java.io.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
Scanner.useRadix method. The
Scanner.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
java.util.Locale.getDefault method; it may be changed via the
Scanner.useLocale method. The
Scanner.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
java.text.DecimalFormat DecimalFormat object, df, and its and
java.text.DecimalFormatSymbols DecimalFormatSymbols object,
dfs.
| LocalGroupSeparator |
The character used to separate thousands groups,
i.e., dfs.
java.text.DecimalFormatSymbols.getGroupingSeparatorgetGroupingSeparator() |
| LocalDecimalSeparator |
The character used for the decimal point,
i.e., dfs.
java.text.DecimalFormatSymbols.getDecimalSeparatorgetDecimalSeparator() |
| LocalPositivePrefix |
The string that appears before a positive number (may
be empty), i.e., df.
java.text.DecimalFormat.getPositivePrefixgetPositivePrefix() |
| LocalPositiveSuffix |
The string that appears after a positive number (may be
empty), i.e., df.
java.text.DecimalFormat.getPositiveSuffixgetPositiveSuffix() |
| LocalNegativePrefix |
The string that appears before a negative number (may
be empty), i.e., df.
java.text.DecimalFormat.getNegativePrefixgetNegativePrefix() |
| LocalNegativeSuffix |
The string that appears after a negative number (may be
empty), i.e., df.
java.text.DecimalFormat.getNegativeSuffixgetNegativeSuffix() |
| LocalNaN |
The string that represents not-a-number for
floating-point values,
i.e., dfs.
java.text.DecimalFormatSymbols.getNaNgetNaN() |
| LocalInfinity |
The string that represents infinity for floating-point
values, i.e., dfs.
java.text.DecimalFormatSymbols.getInfinitygetInfinity() |
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
java.lang.Character.isDigit 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.
version:
1.34, 06/11/07
since:
1.5 |
| Constructor Summary | |
| public | Scanner(Readable source)
Constructs a new Scanner that produces values scanned
from the specified source. | | public | Scanner(InputStream source)
Constructs a new Scanner that produces values scanned
from the specified input stream. | | public | Scanner(InputStream source, String charsetName)
Constructs a new Scanner that produces values scanned
from the specified input stream. | | public | Scanner(File source)
Constructs a new Scanner that produces values scanned
from the specified file. | | public | Scanner(File source, String charsetName)
Constructs a new Scanner that produces values scanned
from the specified file. | | public | Scanner(String source)
Constructs a new Scanner that produces values scanned
from the specified string. | | public | Scanner(ReadableByteChannel source)
Constructs a new Scanner that produces values scanned
from the specified channel. | | public | Scanner(ReadableByteChannel source, String charsetName)
Constructs a new Scanner that produces values scanned
from the specified channel. |
| Method Summary | |
| public void | close()
Closes this scanner.
If this scanner has not yet been closed then if its underlying
also implements the
java.io.Closeable interface then the readable's close method
will be invoked. | | public Pattern | delimiter()
Returns the Pattern this Scanner is currently
using to match delimiters. | | public String | findInLine(String pattern)
Attempts to find the next occurrence of a pattern constructed from the
specified string, ignoring delimiters. | | public String | findInLine(Pattern pattern)
Attempts to find the next occurrence of the specified pattern ignoring
delimiters. | | public String | findWithinHorizon(String pattern, int horizon)
Attempts to find the next occurrence of a pattern constructed from the
specified string, ignoring delimiters. | | 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. | | public boolean | hasNext()
Returns true if this scanner has another token in its input. | | public boolean | hasNext(String pattern)
Returns true if the next token matches the pattern constructed from the
specified string. | | 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. | | public boolean | hasNextBigDecimal()
Returns true if the next token in this scanner's input can be
interpreted as a BigDecimal using the
Scanner.nextBigDecimal method. | | 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
Scanner.nextBigInteger method. | | 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
Scanner.nextBigInteger method. | | 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". | | 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
Scanner.nextByte method. | | 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
Scanner.nextByte method. | | public boolean | hasNextDouble()
Returns true if the next token in this scanner's input can be
interpreted as a double value using the
Scanner.nextDouble
method. | | public boolean | hasNextFloat()
Returns true if the next token in this scanner's input can be
interpreted as a float value using the
Scanner.nextFloat
method. | | 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
Scanner.nextInt method. | | 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
Scanner.nextInt method. | | public boolean | hasNextLine()
Returns true if there is another line in the input of this scanner.
This method may block while waiting for input. | | 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
Scanner.nextLong method. | | 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
Scanner.nextLong method. | | 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
Scanner.nextShort method. | | 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
Scanner.nextShort method. | | public IOException | ioException()
Returns the IOException last thrown by this
Scanner's underlying Readable. | | public Locale | locale()
Returns this scanner's locale. | | public MatchResult | match()
Returns the match result of the last scanning operation performed
by this scanner. | | 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. | | public String | next(String pattern)
Returns the next token if it matches the pattern constructed from the
specified string. | | public String | next(Pattern pattern)
Returns the next token if it matches the specified pattern. | | public BigDecimal | nextBigDecimal()
Scans the next token of the input as a
java.math.BigDecimalBigDecimal . | | public BigInteger | nextBigInteger()
Scans the next token of the input as a
java.math.BigIntegerBigInteger . | | public BigInteger | nextBigInteger(int radix)
Scans the next token of the input as a
java.math.BigIntegerBigInteger . | | public boolean | nextBoolean()
Scans the next token of the input into a boolean value and returns
that value. | | public byte | nextByte()
Scans the next token of the input as a byte. | | 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. | | 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 Character.digit , prepending a
negative sign (-) if the locale specific negative prefixes and suffixes
were present, and passing the resulting string to
Double.parseDouble Double.parseDouble . | | 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. | | public int | nextInt()
Scans the next token of the input as an int. | | 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. | | 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. | | public long | nextLong()
Scans the next token of the input as a long. | | 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. | | public short | nextShort()
Scans the next token of the input as a short. | | 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. | | public int | radix()
Returns this scanner's default radix. | | public void | remove()
The remove operation is not supported by this implementation of
Iterator. | | public Scanner | reset()
Resets this scanner. | | public Scanner | skip(Pattern pattern)
Skips input that matches the specified pattern, ignoring delimiters. | | public Scanner | skip(String pattern)
Skips input that matches a pattern constructed from the specified
string. | | public String | toString()
Returns the string representation of this Scanner. | | public Scanner | useDelimiter(Pattern pattern)
Sets this scanner's delimiting pattern to the specified pattern. | | public Scanner | useDelimiter(String pattern)
Sets this scanner's delimiting pattern to a pattern constructed from
the specified String. | | public Scanner | useLocale(Locale locale)
Sets this scanner's locale to the specified locale. | | public Scanner | useRadix(int radix)
Sets this scanner's default radix to the specified radix. |
| Scanner | | public Scanner(Readable source)(Code) | | Constructs a new Scanner that produces values scanned
from the specified source.
Parameters:
source - A character source implementing the Readableinterface |
| Scanner | | public Scanner(InputStream source)(Code) | | 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
.
Parameters:
source - An input stream to be scanned |
| Scanner | | public Scanner(InputStream source, String charsetName)(Code) | | 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 - An input stream to be scanned
Parameters:
charsetName - The encoding type used to convert bytes from thestream into characters to be scanned
throws:
IllegalArgumentException - if the specified character setdoes not exist |
| Scanner | | public Scanner(File source) throws FileNotFoundException(Code) | | 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
.
Parameters:
source - A file to be scanned
throws:
FileNotFoundException - if source is not found |
| Scanner | | public Scanner(File source, String charsetName) throws FileNotFoundException(Code) | | 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 - A file to be scanned
Parameters:
charsetName - The encoding type used to convert bytes from the fileinto characters to be scanned
throws:
FileNotFoundException - if source is not found
throws:
IllegalArgumentException - if the specified encoding is not found |
| Scanner | | public Scanner(String source)(Code) | | Constructs a new Scanner that produces values scanned
from the specified string.
Parameters:
source - A string to scan |
| Scanner | | public Scanner(ReadableByteChannel source)(Code) | | 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
.
Parameters:
source - A channel to scan |
| Scanner | | public Scanner(ReadableByteChannel source, String charsetName)(Code) | | 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 - A channel to scan
Parameters:
charsetName - The encoding type used to convert bytes from thechannel into characters to be scanned
throws:
IllegalArgumentException - if the specified character setdoes not exist |
| close | | public void close()(Code) | | Closes this scanner.
If this scanner has not yet been closed then if its underlying
also implements the
java.io.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()(Code) | | Returns the Pattern this Scanner is currently
using to match delimiters.
this scanner's delimiting pattern. |
| findInLine | | public String findInLine(String pattern)(Code) | | 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 - a string specifying the pattern to search for the text that matched the specified pattern
throws:
IllegalStateException - if this scanner is closed |
| findInLine | | public String findInLine(Pattern pattern)(Code) | | 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 - the pattern to scan for the text that matched the specified pattern
throws:
IllegalStateException - if this scanner is closed |
| findWithinHorizon | | public String findWithinHorizon(String pattern, int horizon)(Code) | | 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 - a string specifying the pattern to search for the text that matched the specified pattern
throws:
IllegalStateException - if this scanner is closed
throws:
IllegalArgumentException - if horizon is negative |
| findWithinHorizon | | public String findWithinHorizon(Pattern pattern, int horizon)(Code) | | 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 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 - the pattern to scan for the text that matched the specified pattern
throws:
IllegalStateException - if this scanner is closed
throws:
IllegalArgumentException - if horizon is negative |
| hasNext | | public boolean hasNext()(Code) | | 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.
true if and only if this scanner has another token
throws:
IllegalStateException - if this scanner is closed
See Also: java.util.Iterator |
| hasNext | | public boolean hasNext(String pattern)(Code) | | 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 - a string specifying the pattern to scan true if and only if this scanner has another token matchingthe specified pattern
throws:
IllegalStateException - if this scanner is closed |
| hasNext | | public boolean hasNext(Pattern pattern)(Code) | | 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 - the pattern to scan for true if and only if this scanner has another token matchingthe specified pattern
throws:
IllegalStateException - if this scanner is closed |
| hasNextBigDecimal | | public boolean hasNextBigDecimal()(Code) | | Returns true if the next token in this scanner's input can be
interpreted as a BigDecimal using the
Scanner.nextBigDecimal method. The scanner does not advance past any
input.
true if and only if this scanner's next token is a validBigDecimal
throws:
IllegalStateException - if this scanner is closed |
| hasNextBigInteger | | public boolean hasNextBigInteger()(Code) | | Returns true if the next token in this scanner's input can be
interpreted as a BigInteger in the default radix using the
Scanner.nextBigInteger method. The scanner does not advance past any
input.
true if and only if this scanner's next token is a validBigInteger
throws:
IllegalStateException - if this scanner is closed |
| hasNextBigInteger | | public boolean hasNextBigInteger(int radix)(Code) | | Returns true if the next token in this scanner's input can be
interpreted as a BigInteger in the specified radix using
the
Scanner.nextBigInteger method. The scanner does not advance past
any input.
Parameters:
radix - the radix used to interpret the token as an integer true if and only if this scanner's next token is a validBigInteger
throws:
IllegalStateException - if this scanner is closed |
| hasNextBoolean | | public boolean hasNextBoolean()(Code) | | 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.
true if and only if this scanner's next token is a validboolean value
throws:
IllegalStateException - if this scanner is closed |
| hasNextByte | | public boolean hasNextByte()(Code) | | Returns true if the next token in this scanner's input can be
interpreted as a byte value in the default radix using the
Scanner.nextByte method. The scanner does not advance past any input.
true if and only if this scanner's next token is a validbyte value
throws:
IllegalStateException - if this scanner is closed |
| hasNextByte | | public boolean hasNextByte(int radix)(Code) | | Returns true if the next token in this scanner's input can be
interpreted as a byte value in the specified radix using the
Scanner.nextByte method. The scanner does not advance past any input.
Parameters:
radix - the radix used to interpret the token as a byte value true if and only if this scanner's next token is a validbyte value
throws:
IllegalStateException - if this scanner is closed |
| hasNextDouble | | public boolean hasNextDouble()(Code) | | Returns true if the next token in this scanner's input can be
interpreted as a double value using the
Scanner.nextDouble
method. The scanner does not advance past any input.
true if and only if this scanner's next token is a validdouble value
throws:
IllegalStateException - if this scanner is closed |
| hasNextFloat | | public boolean hasNextFloat()(Code) | | Returns true if the next token in this scanner's input can be
interpreted as a float value using the
Scanner.nextFloat
method. The scanner does not advance past any input.
true if and only if this scanner's next token is a validfloat value
throws:
IllegalStateException - if this scanner is closed |
| hasNextInt | | public boolean hasNextInt()(Code) | | Returns true if the next token in this scanner's input can be
interpreted as an int value in the default radix using the
Scanner.nextInt method. The scanner does not advance past any input.
true if and only if this scanner's next token is a validint value
throws:
IllegalStateException - if this scanner is closed |
| hasNextInt | | public boolean hasNextInt(int radix)(Code) | | Returns true if the next token in this scanner's input can be
interpreted as an int value in the specified radix using the
Scanner.nextInt method. The scanner does not advance past any input.
Parameters:
radix - the radix used to interpret the token as an int value true if and only if this scanner's next token is a validint value
throws:
IllegalStateException - if this scanner is closed |
| hasNextLine | | public boolean hasNextLine()(Code) | | 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.
true if and only if this scanner has another line of input
throws:
IllegalStateException - if this scanner is closed |
| hasNextLong | | public boolean hasNextLong()(Code) | | Returns true if the next token in this scanner's input can be
interpreted as a long value in the default radix using the
Scanner.nextLong method. The scanner does not advance past any input.
true if and only if this scanner's next token is a validlong value
throws:
IllegalStateException - if this scanner is closed |
| hasNextLong | | public boolean hasNextLong(int radix)(Code) | | Returns true if the next token in this scanner's input can be
interpreted as a long value in the specified radix using the
Scanner.nextLong method. The scanner does not advance past any input.
Parameters:
radix - the radix used to interpret the token as a long value true if and only if this scanner's next token is a validlong value
throws:
IllegalStateException - if this scanner is closed |
| hasNextShort | | public boolean hasNextShort()(Code) | | Returns true if the next token in this scanner's input can be
interpreted as a short value in the default radix using the
Scanner.nextShort method. The scanner does not advance past any input.
true if and only if this scanner's next token is a validshort value in the default radix
throws:
IllegalStateException - if this scanner is closed |
| hasNextShort | | public boolean hasNextShort(int radix)(Code) | | Returns true if the next token in this scanner's input can be
interpreted as a short value in the specified radix using the
Scanner.nextShort method. The scanner does not advance past any input.
Parameters:
radix - the radix used to interpret the token as a short value true if and only if this scanner's next token is a validshort value in the specified radix
throws:
IllegalStateException - if this scanner is closed |
| ioException | | public IOException ioException()(Code) | | Returns the IOException last thrown by this
Scanner's underlying Readable. This method
returns null if no such exception exists.
the last exception thrown by this scanner's readable |
| locale | | public Locale locale()(Code) | | Returns this scanner's locale.
A scanner's locale affects many elements of its default
primitive matching regular expressions; see
localized numbers above.
this scanner's locale |
| match | | public MatchResult match()(Code) | | 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 nextmethods of Scanner
make a match result available if they complete without throwing an
exception. For instance, after an invocation of the
Scanner.nextInt method that returned an int, this method returns a
MatchResult for the search of the
Integer regular expression
defined above. Similarly the
Scanner.findInLine ,
Scanner.findWithinHorizon , and
Scanner.skip methods will make a
match available if they succeed.
a match result for the last match operation
throws:
IllegalStateException - If no match result is available |
| next | | public String next()(Code) | | 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
Scanner.hasNext returned
true.
the next token
throws:
NoSuchElementException - if no more tokens are available
throws:
IllegalStateException - if this scanner is closed
See Also: java.util.Iterator |
| next | | public String next(String pattern)(Code) | | 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 - a string specifying the pattern to scan the next token
throws:
NoSuchElementException - if no such tokens are available
throws:
IllegalStateException - if this scanner is closed |
| next | | public String next(Pattern pattern)(Code) | | 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
Scanner.hasNext(Pattern) returned true.
If the match is successful, the scanner advances past the input that
matched the pattern.
Parameters:
pattern - the pattern to scan for the next token
throws:
NoSuchElementException - if no more tokens are available
throws:
IllegalStateException - if this scanner is closed |
| nextBigInteger | | public BigInteger nextBigInteger()(Code) | | Scans the next token of the input as a
java.math.BigIntegerBigInteger .
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.
the BigInteger scanned from the input
throws:
InputMismatchException - if the next token does not match the Integerregular expression, or is out of range
throws:
NoSuchElementException - if the input is exhausted
throws:
IllegalStateException - if this scanner is closed |
| nextBigInteger | | public BigInteger nextBigInteger(int radix)(Code) | | Scans the next token of the input as a
java.math.BigIntegerBigInteger .
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 Character.digit , and passing the
resulting string to the
java.math.BigInteger.BigInteger(java.lang.String) BigInteger(String, int) constructor with the specified radix.
Parameters:
radix - the radix used to interpret the token the BigInteger scanned from the input
throws:
InputMismatchException - if the next token does not match the Integerregular expression, or is out of range
throws:
NoSuchElementException - if the input is exhausted
throws:
IllegalStateException - if this scanner is closed |
| nextBoolean | | public boolean nextBoolean()(Code) | | 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.
the boolean scanned from the input
throws:
InputMismatchException - if the next token is not a valid boolean
throws:
NoSuchElementException - if input is exhausted
throws:
IllegalStateException - if this scanner is closed |
| nextByte | | public byte nextByte()(Code) | | 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.
the byte scanned from the input
throws:
InputMismatchException - if the next token does not match the Integerregular expression, or is out of range
throws:
NoSuchElementException - if input is exhausted
throws:
IllegalStateException - if this scanner is closed |
| nextByte | | public byte nextByte(int radix)(Code) | | 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 Character.digit , prepending a
negative sign (-) if the locale specific negative prefixes and suffixes
were present, and passing the resulting string to
Byte.parseByte(Stringint) Byte.parseByte with the
specified radix.
Parameters:
radix - the radix used to interpret the token as a byte value the byte scanned from the input
throws:
InputMismatchException - if the next token does not match the Integerregular expression, or is out of range
throws:
NoSuchElementException - if input is exhausted
throws:
IllegalStateException - if this scanner is closed |
| nextDouble | | public double nextDouble()(Code) | | 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 Character.digit , prepending a
negative sign (-) if the locale specific negative prefixes and suffixes
were present, and passing the resulting string to
Double.parseDouble Double.parseDouble . If the token matches
the localized NaN or infinity strings, then either "Nan" or "Infinity"
is passed to
Double.parseDouble(String) Double.parseDouble as
appropriate.
the double scanned from the input
throws:
InputMismatchException - if the next token does not match the Floatregular expression, or is out of range
throws:
NoSuchElementException - if the input is exhausted
throws:
IllegalStateException - if this scanner is closed |
| nextFloat | | public float nextFloat()(Code) | | 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 Character.digit , prepending a
negative sign (-) if the locale specific negative prefixes and suffixes
were present, and passing the resulting string to
Float.parseFloat Float.parseFloat . If the token matches
the localized NaN or infinity strings, then either "Nan" or "Infinity"
is passed to
Float.parseFloat(String) Float.parseFloat as
appropriate.
the float scanned from the input
throws:
InputMismatchException - if the next token does not match the Floatregular expression, or is out of range
throws:
NoSuchElementException - if input is exhausted
throws:
IllegalStateException - if this scanner is closed |
| nextInt | | public int nextInt()(Code) | | 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.
the int scanned from the input
throws:
InputMismatchException - if the next token does not match the Integerregular expression, or is out of range
throws:
NoSuchElementException - if input is exhausted
throws:
IllegalStateException - if this scanner is closed |
| nextInt | | public int nextInt(int radix)(Code) | | 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 Character.digit , prepending a
negative sign (-) if the locale specific negative prefixes and suffixes
were present, and passing the resulting string to
Integer.parseInt(Stringint) Integer.parseInt with the
specified radix.
Parameters:
radix - the radix used to interpret the token as an int value the int scanned from the input
throws:
InputMismatchException - if the next token does not match the Integerregular expression, or is out of range
throws:
NoSuchElementException - if input is exhausted
throws:
IllegalStateException - if this scanner is closed |
| nextLine | | public String nextLine()(Code) | | 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.
the line that was skipped
throws:
NoSuchElementException - if no line was found
throws:
IllegalStateException - if this scanner is closed |
| nextLong | | public long nextLong()(Code) | | 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.
the long scanned from the input
throws:
InputMismatchException - if the next token does not match the Integerregular expression, or is out of range
throws:
NoSuchElementException - if input is exhausted
throws:
IllegalStateException - if this scanner is closed |
| nextLong | | public long nextLong(int radix)(Code) | | 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 Character.digit , prepending a
negative sign (-) if the locale specific negative prefixes and suffixes
were present, and passing the resulting string to
Long.parseLong(Stringint) Long.parseLong with the
specified radix.
Parameters:
radix - the radix used to interpret the token as an int value the long scanned from the input
throws:
InputMismatchException - if the next token does not match the Integerregular expression, or is out of range
throws:
NoSuchElementException - if input is exhausted
throws:
IllegalStateException - if this scanner is closed |
| nextShort | | public short nextShort()(Code) | | 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.
the short scanned from the input
throws:
InputMismatchException - if the next token does not match the Integerregular expression, or is out of range
throws:
NoSuchElementException - if input is exhausted
throws:
IllegalStateException - if this scanner is closed |
| nextShort | | public short nextShort(int radix)(Code) | | 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 Character.digit , prepending a
negative sign (-) if the locale specific negative prefixes and suffixes
were present, and passing the resulting string to
Short.parseShort(Stringint) Short.parseShort with the
specified radix.
Parameters:
radix - the radix used to interpret the token as a short value the short scanned from the input
throws:
InputMismatchException - if the next token does not match the Integerregular expression, or is out of range
throws:
NoSuchElementException - if input is exhausted
throws:
IllegalStateException - if this scanner is closed |
| radix | | public int radix()(Code) | | Returns this scanner's default radix.
A scanner's radix affects elements of its default
number matching regular expressions; see
localized numbers above.
the default radix of this scanner |
| reset | | public Scanner reset()(Code) | | Resets this scanner.
Resetting a scanner discards all of its explicit state
information which may have been changed by invocations of
Scanner.useDelimiter ,
Scanner.useLocale , or
Scanner.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())
.useRadix(10);
this scanner
since:
1.6 |
| skip | | public Scanner skip(Pattern pattern)(Code) | | 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 - a string specifying the pattern to skip over this scanner
throws:
NoSuchElementException - if the specified pattern is not found
throws:
IllegalStateException - if this scanner is closed |
| skip | | public Scanner skip(String pattern)(Code) | | 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 - a string specifying the pattern to skip over this scanner
throws:
IllegalStateException - if this scanner is closed |
| toString | | public String toString()(Code) | | 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.
The string representation of this scanner |
| useDelimiter | | public Scanner useDelimiter(Pattern pattern)(Code) | | Sets this scanner's delimiting pattern to the specified pattern.
Parameters:
pattern - A delimiting pattern this scanner |
| useDelimiter | | public Scanner useDelimiter(String pattern)(Code) | | 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
Scanner.reset method will set the scanner's delimiter
to the default.
Parameters:
pattern - A string specifying a delimiting pattern this scanner |
| useLocale | | public Scanner useLocale(Locale locale)(Code) | | 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
Scanner.reset method will set the scanner's locale to
the initial locale.
Parameters:
locale - A string specifying the locale to use this scanner |
| useRadix | | public Scanner useRadix(int radix)(Code) | | 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
Scanner.reset method will set the scanner's radix to
10.
Parameters:
radix - The radix to use when scanning numbers this scanner
throws:
IllegalArgumentException - if radix is out of range |
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