Added in API level 1

Scanner

class Scanner : MutableIterator<String!>, Closeable

kotlin.Any
↳	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:

<code>Scanner sc = new Scanner(System.in);
      int i = sc.nextInt();
  </code>

As another example, this code allows long types to be assigned from entries in a file myNumbers:

<code>Scanner sc = new Scanner(new File("myNumbers"));
       while (sc.hasNextLong()) {
           long aLong = sc.nextLong();
       }
  </code>

The scanner can also use delimiters other than whitespace. This example reads several items in from a string:

<code>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();
  </code>

prints the following output:

<code>1
      2
      red
      blue
  </code>

The same output can be generated with this code, which uses a regular expression to parse all four tokens at once:

<code>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&lt;=result.groupCount(); i++)
          System.out.println(result.group(i));
      s.close();
  </code>

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 interface. If an invocation of the underlying readable's read() method throws an 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 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 useRadix 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 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 java.lang.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(source: Readable!) Constructs a new Scanner that produces values scanned from the specified source.
Scanner(source: InputStream!) Constructs a new Scanner that produces values scanned from the specified input stream.
Scanner(source: InputStream!, charsetName: String!) Constructs a new Scanner that produces values scanned from the specified input stream.
Scanner(source: InputStream!, charset: Charset!) Constructs a new Scanner that produces values scanned from the specified input stream.
Scanner(source: File!) Constructs a new Scanner that produces values scanned from the specified file.
Scanner(source: File!, charsetName: String!) Constructs a new Scanner that produces values scanned from the specified file.
Scanner(source: File!, charset: Charset!) Constructs a new Scanner that produces values scanned from the specified file.
Scanner(source: Path!) Constructs a new Scanner that produces values scanned from the specified file.
Scanner(source: Path!, charsetName: String!) Constructs a new Scanner that produces values scanned from the specified file.
Scanner(source: Path!, charset: Charset!) Constructs a new Scanner that produces values scanned from the specified file.
Scanner(source: String!) Constructs a new Scanner that produces values scanned from the specified string.
Scanner(source: ReadableByteChannel!) Constructs a new Scanner that produces values scanned from the specified channel.
Scanner(source: ReadableByteChannel!, charsetName: String!) Constructs a new Scanner that produces values scanned from the specified channel.
Scanner(source: ReadableByteChannel!, charset: Charset!) Constructs a new Scanner that produces values scanned from the specified channel.

Public methods
Unit	close() Closes this scanner.
Pattern!	delimiter() Returns the Pattern this Scanner is currently using to match delimiters.
Stream<MatchResult!>!	findAll(pattern: Pattern!) Returns a stream of match results from this scanner.
Stream<MatchResult!>!	findAll(patString: String!) Returns a stream of match results that match the provided pattern string.
String!	findInLine(pattern: String!) 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: String!, horizon: Int) Attempts to find the next occurrence of a pattern constructed from the specified string, ignoring delimiters.
String!	findWithinHorizon(pattern: Pattern!, horizon: Int) Attempts to find the next occurrence of the specified pattern.
Boolean	hasNext() Returns true if this scanner has another token in its input.
Boolean	hasNext(pattern: String!) 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 BigDecimal using the nextBigDecimal method.
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.
Boolean	hasNextBigInteger(radix: Int) 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.
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 #nextByte method.
Boolean	hasNextByte(radix: Int) 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.
Boolean	hasNextDouble() Returns true if the next token in this scanner's input can be interpreted as a double value using the nextDouble method.
Boolean	hasNextFloat() Returns true if the next token in this scanner's input can be interpreted as a float value using the nextFloat method.
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.
Boolean	hasNextInt(radix: Int) 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.
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 #nextLong method.
Boolean	hasNextLong(radix: Int) 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.
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.
Boolean	hasNextShort(radix: Int) 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.
IOException!	ioException() Returns the IOException last thrown by this Scanner's underlying Readable.
Locale!	locale() Returns this scanner's locale.
MatchResult!	match() Returns the match result of the last scanning operation performed by this scanner.
String!	next() Finds and returns the next complete token from this scanner.
String!	next(pattern: String!) Returns the next token if it matches the pattern constructed from the specified string.
String!	next(pattern: Pattern!) Returns the next token if it matches the specified pattern.
BigDecimal!	nextBigDecimal() Scans the next token of the input as a BigDecimal.
BigInteger!	nextBigInteger() Scans the next token of the input as a BigInteger.
BigInteger!	nextBigInteger(radix: Int) Scans the next token of the input as a BigInteger.
Boolean	nextBoolean() Scans the next token of the input into a boolean value and returns that value.
Byte	nextByte() Scans the next token of the input as a byte.
Byte	nextByte(radix: Int) Scans the next token of the input as a byte.
Double	nextDouble() Scans the next token of the input as a double.
Float	nextFloat() Scans the next token of the input as a float.
Int	nextInt() Scans the next token of the input as an int.
Int	nextInt(radix: Int) Scans the next token of the input as an int.
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.
Long	nextLong(radix: Int) Scans the next token of the input as a long.
Short	nextShort() Scans the next token of the input as a short.
Short	nextShort(radix: Int) Scans the next token of the input as a short.
Int	radix() Returns this scanner's default radix.
Unit	remove() The remove operation is not supported by this implementation of Iterator.
Scanner!	reset() Resets this scanner.
Scanner!	skip(pattern: Pattern!) Skips input that matches the specified pattern, ignoring delimiters.
Scanner!	skip(pattern: String!) Skips input that matches a pattern constructed from the specified string.
String	toString() Returns the string representation of this Scanner.
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(pattern: String!) Sets this scanner's delimiting pattern to a pattern constructed from the specified String.
Scanner!	useLocale(locale: Locale!) Sets this scanner's locale to the specified locale.
Scanner!	useRadix(radix: Int) Sets this scanner's default radix to the specified radix.

Public constructors

Scanner

Added in API level 1

Scanner(source: Readable!)

Constructs a new Scanner that produces values scanned from the specified source.

Parameters
source	Readable!: A character source implementing the Readable interface

Scanner

Added in API level 1

Scanner(source: InputStream!)

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

Added in API level 1

Scanner(
    source: InputStream!, 
    charsetName: String!)

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

Exceptions
java.lang.IllegalArgumentException	if the specified character set does not exist

Scanner

Added in API level 34

Scanner(
    source: InputStream!, 
    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

Added in API level 1

Scanner(source: File!)

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

Exceptions
java.io.FileNotFoundException	if source is not found

Scanner

Added in API level 1

Scanner(
    source: File!, 
    charsetName: String!)

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

Exceptions
java.io.FileNotFoundException	if source is not found
java.lang.IllegalArgumentException	if the specified encoding is not found

Scanner

Added in API level 34

Scanner(
    source: File!, 
    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

Exceptions
java.io.IOException	if an I/O error occurs opening the source

Scanner

Added in API level 26

Scanner(source: Path!)

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

Exceptions
java.io.IOException	if an I/O error occurs opening source

Scanner

Added in API level 26

Scanner(
    source: Path!, 
    charsetName: String!)

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

Exceptions
java.io.IOException	if an I/O error occurs opening source
java.lang.IllegalArgumentException	if the specified encoding is not found

Scanner

Added in API level 34

Scanner(
    source: Path!, 
    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

Exceptions
java.io.IOException	if an I/O error occurs opening the source

Scanner

Added in API level 1

Scanner(source: String!)

Constructs a new Scanner that produces values scanned from the specified string.

Parameters
source	String!: A string to scan

Scanner

Added in API level 1

Scanner(source: ReadableByteChannel!)

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

Added in API level 1

Scanner(
    source: ReadableByteChannel!, 
    charsetName: String!)

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

Exceptions
java.lang.IllegalArgumentException	if the specified character set does not exist

Scanner

Added in API level 34

Scanner(
    source: ReadableByteChannel!, 
    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

Public methods

close

Added in API level 1

fun close(): Unit

Closes this scanner.

If this scanner has not yet been closed then if its underlying readable also implements the 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.

Exceptions
java.lang.Exception	if this resource cannot be closed
java.io.IOException	if an I/O error occurs

delimiter

Added in API level 1

fun delimiter(): Pattern!

Returns the Pattern this Scanner is currently using to match delimiters.

Return
Pattern!	this scanner's delimiting pattern.

findAll

Added in API level 34

fun findAll(pattern: Pattern!): Stream<MatchResult!>!

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 java.util.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.

Parameters
pattern	Pattern!: the pattern to be matched

Return
Stream<MatchResult!>!	a sequential stream of match results

Exceptions
java.lang.NullPointerException	if pattern is null
java.lang.IllegalStateException	if this scanner is closed

findAll

Added in API level 34

fun findAll(patString: String!): Stream<MatchResult!>!

Returns a stream of match results that match the provided pattern string. The effect is equivalent to the following code:

<code>scanner.findAll(Pattern.compile(patString))
  </code>

Parameters
patString	String!: the pattern string

Return
Stream<MatchResult!>!	a sequential stream of match results

Exceptions
java.lang.NullPointerException	if patString is null
java.lang.IllegalStateException	if this scanner is closed
java.util.regex.PatternSyntaxException	if the regular expression's syntax is invalid

See Also

• java.util.regex.Pattern

findInLine

Added in API level 1

fun findInLine(pattern: String!): String!

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

Return
String!	the text that matched the specified pattern

Exceptions
java.lang.IllegalStateException	if this scanner is closed

findInLine

Added in API level 1

fun findInLine(pattern: Pattern!): String!

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

Return
String!	the text that matched the specified pattern

Exceptions
java.lang.IllegalStateException	if this scanner is closed

findWithinHorizon

Added in API level 1

fun findWithinHorizon(
    pattern: String!, 
    horizon: Int
): String!

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

Return
String!	the text that matched the specified pattern

Exceptions
java.lang.IllegalStateException	if this scanner is closed
java.lang.IllegalArgumentException	if horizon is negative

findWithinHorizon

Added in API level 1

fun findWithinHorizon(
    pattern: Pattern!, 
    horizon: Int
): String!

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 java.util.regex.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	Pattern!: the pattern to scan for
horizon	Int: the search horizon

Return
String!	the text that matched the specified pattern

Exceptions
java.lang.IllegalStateException	if this scanner is closed
java.lang.IllegalArgumentException	if horizon is negative

hasNext

Added in API level 1

fun hasNext(): Boolean

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.

Return
Boolean	true if and only if this scanner has another token

Exceptions
java.lang.IllegalStateException	if this scanner is closed

See Also

• java.util.Iterator

hasNext

Added in API level 1

fun hasNext(pattern: String!): Boolean

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

Return
Boolean	true if and only if this scanner has another token matching the specified pattern

Exceptions
java.lang.IllegalStateException	if this scanner is closed

hasNext

Added in API level 1

fun hasNext(pattern: Pattern!): Boolean

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

Return
Boolean	true if and only if this scanner has another token matching the specified pattern

Exceptions
java.lang.IllegalStateException	if this scanner is closed

hasNextBigDecimal

Added in API level 1

fun hasNextBigDecimal(): Boolean

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.

Return
Boolean	true if and only if this scanner's next token is a valid BigDecimal

Exceptions
java.lang.IllegalStateException	if this scanner is closed

hasNextBigInteger

Added in API level 1

fun hasNextBigInteger(): Boolean

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.

Return
Boolean	true if and only if this scanner's next token is a valid BigInteger

Exceptions
java.lang.IllegalStateException	if this scanner is closed

hasNextBigInteger

Added in API level 1

fun hasNextBigInteger(radix: Int): Boolean

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

Return
Boolean	true if and only if this scanner's next token is a valid BigInteger

Exceptions
java.lang.IllegalStateException	if this scanner is closed
java.lang.IllegalArgumentException	if the radix is out of range

hasNextBoolean

Added in API level 1

fun hasNextBoolean(): Boolean

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.

Return
Boolean	true if and only if this scanner's next token is a valid boolean value

Exceptions
java.lang.IllegalStateException	if this scanner is closed

hasNextByte

Added in API level 1

fun hasNextByte(): Boolean

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.

Return
Boolean	true if and only if this scanner's next token is a valid byte value

Exceptions
java.lang.IllegalStateException	if this scanner is closed

hasNextByte

Added in API level 1

fun hasNextByte(radix: Int): Boolean

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

Return
Boolean	true if and only if this scanner's next token is a valid byte value

Exceptions
java.lang.IllegalStateException	if this scanner is closed
java.lang.IllegalArgumentException	if the radix is out of range

hasNextDouble

Added in API level 1

fun hasNextDouble(): Boolean

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.

Return
Boolean	true if and only if this scanner's next token is a valid double value

Exceptions
java.lang.IllegalStateException	if this scanner is closed

hasNextFloat

Added in API level 1

fun hasNextFloat(): Boolean

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.

Return
Boolean	true if and only if this scanner's next token is a valid float value

Exceptions
java.lang.IllegalStateException	if this scanner is closed

hasNextInt

Added in API level 1

fun hasNextInt(): Boolean

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.

Return
Boolean	true if and only if this scanner's next token is a valid int value

Exceptions
java.lang.IllegalStateException	if this scanner is closed

hasNextInt

Added in API level 1

fun hasNextInt(radix: Int): Boolean

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

Return
Boolean	true if and only if this scanner's next token is a valid int value

Exceptions
java.lang.IllegalStateException	if this scanner is closed
java.lang.IllegalArgumentException	if the radix is out of range

hasNextLine

Added in API level 1

fun hasNextLine(): Boolean

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.

Return
Boolean	true if and only if this scanner has another line of input

Exceptions
java.lang.IllegalStateException	if this scanner is closed

hasNextLong

Added in API level 1

fun hasNextLong(): Boolean

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.

Return
Boolean	true if and only if this scanner's next token is a valid long value

Exceptions
java.lang.IllegalStateException	if this scanner is closed

hasNextLong

Added in API level 1

fun hasNextLong(radix: Int): Boolean

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

Return
Boolean	true if and only if this scanner's next token is a valid long value

Exceptions
java.lang.IllegalStateException	if this scanner is closed
java.lang.IllegalArgumentException	if the radix is out of range

hasNextShort

Added in API level 1

fun hasNextShort(): Boolean

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.

Return
Boolean	true if and only if this scanner's next token is a valid short value in the default radix

Exceptions
java.lang.IllegalStateException	if this scanner is closed

hasNextShort

Added in API level 1

fun hasNextShort(radix: Int): Boolean

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

Return
Boolean	true if and only if this scanner's next token is a valid short value in the specified radix

Exceptions
java.lang.IllegalStateException	if this scanner is closed
java.lang.IllegalArgumentException	if the radix is out of range

ioException

Added in API level 1

fun ioException(): IOException!

Returns the IOException last thrown by this Scanner's underlying Readable. This method returns null if no such exception exists.

Return
IOException!	the last exception thrown by this scanner's readable

locale

Added in API level 1

fun 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.

Return
Locale!	this scanner's locale

match

Added in API level 1

fun match(): MatchResult!

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.

Return
MatchResult!	a match result for the last match operation

Exceptions
java.lang.IllegalStateException	If no match result is available

next

Added in API level 1

fun next(): String!

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.

Return
String!	the next token

Exceptions
java.util.NoSuchElementException	if no more tokens are available
java.lang.IllegalStateException	if this scanner is closed

See Also

• java.util.Iterator

next

Added in API level 1

fun next(pattern: String!): String!

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

Return
String!	the next token

Exceptions
java.util.NoSuchElementException	if no such tokens are available
java.lang.IllegalStateException	if this scanner is closed

next

Added in API level 1

fun next(pattern: Pattern!): String!

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

Return
String!	the next token

Exceptions
java.util.NoSuchElementException	if no more tokens are available
java.lang.IllegalStateException	if this scanner is closed

nextBigDecimal

Added in API level 1

fun nextBigDecimal(): BigDecimal!

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 java.lang.Character#digit, and passing the resulting string to the BigDecimal(String) constructor.

Return
BigDecimal!	the BigDecimal scanned from the input

Exceptions
java.util.InputMismatchException	if the next token does not match the Decimal regular expression, or is out of range
java.util.NoSuchElementException	if the input is exhausted
java.lang.IllegalStateException	if this scanner is closed

nextBigInteger

Added in API level 1

fun nextBigInteger(): BigInteger!

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.

Return
BigInteger!	the BigInteger scanned from the input

Exceptions
java.util.InputMismatchException	if the next token does not match the Integer regular expression, or is out of range
java.util.NoSuchElementException	if the input is exhausted
java.lang.IllegalStateException	if this scanner is closed

nextBigInteger

Added in API level 1

fun nextBigInteger(radix: Int): BigInteger!

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 java.lang.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

Return
BigInteger!	the BigInteger scanned from the input

Exceptions
java.util.InputMismatchException	if the next token does not match the Integer regular expression, or is out of range
java.util.NoSuchElementException	if the input is exhausted
java.lang.IllegalStateException	if this scanner is closed
java.lang.IllegalArgumentException	if the radix is out of range

nextBoolean

Added in API level 1

fun nextBoolean(): Boolean

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.

Return
Boolean	the boolean scanned from the input

Exceptions
java.util.InputMismatchException	if the next token is not a valid boolean
java.util.NoSuchElementException	if input is exhausted
java.lang.IllegalStateException	if this scanner is closed

nextByte

Added in API level 1

fun nextByte(): Byte

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.

Return
Byte	the byte scanned from the input

Exceptions
java.util.InputMismatchException	if the next token does not match the Integer regular expression, or is out of range
java.util.NoSuchElementException	if input is exhausted
java.lang.IllegalStateException	if this scanner is closed

nextByte

Added in API level 1

fun nextByte(radix: Int): Byte

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 java.lang.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

Return
Byte	the byte scanned from the input

Exceptions
java.util.InputMismatchException	if the next token does not match the Integer regular expression, or is out of range
java.util.NoSuchElementException	if input is exhausted
java.lang.IllegalStateException	if this scanner is closed
java.lang.IllegalArgumentException	if the radix is out of range

nextDouble

Added in API level 1

fun nextDouble(): Double

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 java.lang.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.

Return
Double	the double scanned from the input

Exceptions
java.util.InputMismatchException	if the next token does not match the Float regular expression, or is out of range
java.util.NoSuchElementException	if the input is exhausted
java.lang.IllegalStateException	if this scanner is closed

nextFloat

Added in API level 1

fun nextFloat(): Float

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 java.lang.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.

Return
Float	the float scanned from the input

Exceptions
java.util.InputMismatchException	if the next token does not match the Float regular expression, or is out of range
java.util.NoSuchElementException	if input is exhausted
java.lang.IllegalStateException	if this scanner is closed

nextInt

Added in API level 1

fun nextInt(): Int

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.

Return
Int	the int scanned from the input

Exceptions
java.util.InputMismatchException	if the next token does not match the Integer regular expression, or is out of range
java.util.NoSuchElementException	if input is exhausted
java.lang.IllegalStateException	if this scanner is closed

nextInt

Added in API level 1

fun nextInt(radix: Int): Int

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 java.lang.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

Return
Int	the int scanned from the input

Exceptions
java.util.InputMismatchException	if the next token does not match the Integer regular expression, or is out of range
java.util.NoSuchElementException	if input is exhausted
java.lang.IllegalStateException	if this scanner is closed
java.lang.IllegalArgumentException	if the radix is out of range

nextLine

Added in API level 1

fun nextLine(): String!

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.

Return
String!	the line that was skipped

Exceptions
java.util.NoSuchElementException	if no line was found
java.lang.IllegalStateException	if this scanner is closed

nextLong

Added in API level 1

fun nextLong(): Long

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.

Return
Long	the long scanned from the input

Exceptions
java.util.InputMismatchException	if the next token does not match the Integer regular expression, or is out of range
java.util.NoSuchElementException	if input is exhausted
java.lang.IllegalStateException	if this scanner is closed

nextLong

Added in API level 1

fun nextLong(radix: Int): Long

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 java.lang.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

Return
Long	the long scanned from the input

Exceptions
java.util.InputMismatchException	if the next token does not match the Integer regular expression, or is out of range
java.util.NoSuchElementException	if input is exhausted
java.lang.IllegalStateException	if this scanner is closed
java.lang.IllegalArgumentException	if the radix is out of range

nextShort

Added in API level 1

fun nextShort(): Short

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.

Return
Short	the short scanned from the input

Exceptions
java.util.InputMismatchException	if the next token does not match the Integer regular expression, or is out of range
java.util.NoSuchElementException	if input is exhausted
java.lang.IllegalStateException	if this scanner is closed

nextShort

Added in API level 1

fun nextShort(radix: Int): Short

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 java.lang.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

Return
Short	the short scanned from the input

Exceptions
java.util.InputMismatchException	if the next token does not match the Integer regular expression, or is out of range
java.util.NoSuchElementException	if input is exhausted
java.lang.IllegalStateException	if this scanner is closed
java.lang.IllegalArgumentException	if the radix is out of range

radix

Added in API level 1

fun radix(): Int

Returns this scanner's default radix.

A scanner's radix affects elements of its default number matching regular expressions; see localized numbers above.

Return
Int	the default radix of this scanner

remove

Added in API level 1

fun remove(): Unit

The remove operation is not supported by this implementation of Iterator.

Exceptions
java.lang.UnsupportedOperationException	if this method is invoked.
java.lang.IllegalStateException	if the next method has not yet been called, or the remove method has already been called after the last call to the next method

See Also

• java.util.Iterator

reset

Added in API level 9

fun reset(): Scanner!

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

<code>scanner.useDelimiter("\\p{javaWhitespace}+")
           .useLocale(Locale.getDefault(Locale.Category.FORMAT))
           .useRadix(10);
  </code>

Return
Scanner!	this scanner

skip

Added in API level 1

fun skip(pattern: Pattern!): Scanner!

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

Return
Scanner!	this scanner

Exceptions
java.util.NoSuchElementException	if the specified pattern is not found
java.lang.IllegalStateException	if this scanner is closed

skip

Added in API level 1

fun skip(pattern: String!): Scanner!

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

Return
Scanner!	this scanner

Exceptions
java.lang.IllegalStateException	if this scanner is closed

toString

Added in API level 1

fun toString(): String

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.

Return
String	The string representation of this scanner

tokens

Added in API level 34

fun tokens(): Stream<String!>!

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 java.util.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.

Return
Stream<String!>!	a sequential stream of token strings

Exceptions
java.lang.IllegalStateException	if this scanner is closed

useDelimiter

Added in API level 1

fun useDelimiter(pattern: Pattern!): Scanner!

Sets this scanner's delimiting pattern to the specified pattern.

Parameters
pattern	Pattern!: A delimiting pattern

Return
Scanner!	this scanner

useDelimiter

Added in API level 1

fun useDelimiter(pattern: String!): Scanner!

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

Return
Scanner!	this scanner

useLocale

Added in API level 1

fun useLocale(locale: Locale!): Scanner!

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

Return
Scanner!	this scanner

useRadix

Added in API level 1

fun useRadix(radix: Int): Scanner!

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

Return
Scanner!	this scanner

Exceptions
java.lang.IllegalArgumentException	if radix is out of range