A {@code 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 {@code next} methods. * *
For example, this code allows a user to read a number from * {@code System.in}: *
{@code
* Scanner sc = new Scanner(System.in);
* int i = sc.nextInt();
* }As another example, this code allows {@code long} types to be * assigned from entries in a file {@code myNumbers}: *
{@code
* 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: *
{@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();
* }* prints the following output: *
{@code
* 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: *
{@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<=result.groupCount(); i++)
* System.out.println(result.group(i));
* s.close();
* }The default whitespace delimiter used * by a scanner is as recognized by {@link Character#isWhitespace(char) * Character.isWhitespace()}. The {@link #reset 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 {@link #next} and {@link #hasNext} methods and their * companion methods (such as {@link #nextInt} and * {@link #hasNextInt}) first skip any input that matches the delimiter * pattern, and then attempt to return the next token. Both {@code hasNext()} * and {@code next()} methods may block waiting for further input. Whether a * {@code hasNext()} method blocks has no connection to whether or not its * associated {@code next()} method will block. The {@link #tokens} method * may also block waiting for input. * *
The {@link #findInLine findInLine()}, * {@link #findWithinHorizon findWithinHorizon()}, * {@link #skip skip()}, and {@link #findAll 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 {@link 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 {@code "\\s+"} will return no empty * tokens since it matches multiple instances of the delimiter. The delimiting * pattern {@code "\\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 {@link * java.lang.Readable} interface. If an invocation of the underlying * readable's {@link java.lang.Readable#read read()} method throws an {@link * java.io.IOException} then the scanner assumes that the end of the input * has been reached. The most recent {@code IOException} thrown by the * underlying readable can be retrieved via the {@link #ioException} method. * *
When a {@code Scanner} is closed, it will close its input source * if the source implements the {@link java.io.Closeable} interface. * *
A {@code Scanner} is not safe for multithreaded use without * external synchronization. * *
Unless otherwise mentioned, passing a {@code null} parameter into * any method of a {@code Scanner} will cause a * {@code NullPointerException} to be thrown. * *
A scanner will default to interpreting numbers as decimal unless a * different radix has been set by using the {@link #useRadix} method. The * {@link #reset} method will reset the value of the scanner's radix to * {@code 10} regardless of whether it was previously changed. * *
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 {@link * java.util.Locale#getDefault(Locale.Category) * Locale.getDefault(Locale.Category.FORMAT)} method; it may be changed via the {@link * #useLocale useLocale()} method. The {@link #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 {@link * java.text.DecimalFormat DecimalFormat} object, {@code df}, and its and * {@link java.text.DecimalFormatSymbols DecimalFormatSymbols} object, * {@code dfs}. * *
* **
- LocalGroupSeparator *
- The character used to separate thousands groups, * i.e., {@code dfs.}{@link * java.text.DecimalFormatSymbols#getGroupingSeparator * getGroupingSeparator()} *
- LocalDecimalSeparator *
- The character used for the decimal point, * i.e., {@code dfs.}{@link * java.text.DecimalFormatSymbols#getDecimalSeparator * getDecimalSeparator()} *
- LocalPositivePrefix *
- The string that appears before a positive number (may * be empty), i.e., {@code df.}{@link * java.text.DecimalFormat#getPositivePrefix * getPositivePrefix()} *
- LocalPositiveSuffix *
- The string that appears after a positive number (may be * empty), i.e., {@code df.}{@link * java.text.DecimalFormat#getPositiveSuffix * getPositiveSuffix()} *
- LocalNegativePrefix *
- The string that appears before a negative number (may * be empty), i.e., {@code df.}{@link * java.text.DecimalFormat#getNegativePrefix * getNegativePrefix()} *
- LocalNegativeSuffix *
- The string that appears after a negative number (may be * empty), i.e., {@code df.}{@link * java.text.DecimalFormat#getNegativeSuffix * getNegativeSuffix()} *
- LocalNaN *
- The string that represents not-a-number for * floating-point values, * i.e., {@code dfs.}{@link * java.text.DecimalFormatSymbols#getNaN * getNaN()} *
- LocalInfinity *
- The string that represents infinity for floating-point * values, i.e., {@code dfs.}{@link * java.text.DecimalFormatSymbols#getInfinity * getInfinity()} *
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). * *
( Non0Digit
* Digit{@code ?
* }Digit{@code ?}
* ( LocalGroupSeparator
* Digit
* Digit
* Digit{@code )+ )}
*
* Whitespace is not significant in the above regular expressions.
*
* @since 1.5
*/
public final class Scanner implements Iterator If this scanner has not yet been closed then if its underlying
* {@linkplain java.lang.Readable readable} also implements the {@link
* java.io.Closeable} interface then the readable's {@code 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 {@link IllegalStateException}.
*
*/
public void close() {
if (closed)
return;
if (source instanceof Closeable) {
try {
((Closeable)source).close();
} catch (IOException ioe) {
lastException = ioe;
}
}
sourceClosed = true;
source = null;
closed = true;
}
/**
* Returns the {@code IOException} last thrown by this
* {@code Scanner}'s underlying {@code Readable}. This method
* returns {@code null} if no such exception exists.
*
* @return the last exception thrown by this scanner's readable
*/
public IOException ioException() {
return lastException;
}
/**
* Returns the {@code Pattern} this {@code Scanner} is currently
* using to match delimiters.
*
* @return this scanner's delimiting pattern.
*/
public Pattern delimiter() {
return delimPattern;
}
/**
* Sets this scanner's delimiting pattern to the specified pattern.
*
* @param pattern A delimiting pattern
* @return this scanner
*/
public Scanner useDelimiter(Pattern pattern) {
modCount++;
delimPattern = pattern;
return this;
}
/**
* Sets this scanner's delimiting pattern to a pattern constructed from
* the specified {@code String}.
*
* An invocation of this method of the form
* {@code useDelimiter(pattern)} behaves in exactly the same way as the
* invocation {@code useDelimiter(Pattern.compile(pattern))}.
*
* Invoking the {@link #reset} method will set the scanner's delimiter
* to the default.
*
* @param pattern A string specifying a delimiting pattern
* @return this scanner
*/
public Scanner useDelimiter(String pattern) {
modCount++;
delimPattern = patternCache.forName(pattern);
return this;
}
/**
* Returns this scanner's locale.
*
* A scanner's locale affects many elements of its default
* primitive matching regular expressions; see
* localized numbers above.
*
* @return this scanner's locale
*/
public Locale locale() {
return this.locale;
}
/**
* Sets this scanner's locale to the specified locale.
*
* A scanner's locale affects many elements of its default
* primitive matching regular expressions; see
* localized numbers above.
*
* Invoking the {@link #reset} method will set the scanner's locale to
* the initial locale.
*
* @param locale A string specifying the locale to use
* @return this scanner
*/
public Scanner useLocale(Locale locale) {
if (locale.equals(this.locale))
return this;
modCount++;
this.locale = locale;
DecimalFormat df = null;
NumberFormat nf = NumberFormat.getNumberInstance(locale);
DecimalFormatSymbols dfs = DecimalFormatSymbols.getInstance(locale);
// Android-changed: nf is DecimalFormat.
/*
if (nf instanceof DecimalFormat) {
df = (DecimalFormat) nf;
} else {
// In case where NumberFormat.getNumberInstance() returns
// other instance (non DecimalFormat) based on the provider
// used and java.text.spi.NumberFormatProvider implementations,
// DecimalFormat constructor is used to obtain the instance
LocaleProviderAdapter adapter = LocaleProviderAdapter
.getAdapter(NumberFormatProvider.class, locale);
if (!(adapter instanceof ResourceBundleBasedAdapter)) {
adapter = LocaleProviderAdapter.getResourceBundleBased();
}
String[] all = adapter.getLocaleResources(locale)
.getNumberPatterns();
df = new DecimalFormat(all[0], dfs);
}
*/
df = (DecimalFormat) nf;
// These must be literalized to avoid collision with regex
// metacharacters such as dot or parenthesis
groupSeparator = "\\x{" + Integer.toHexString(dfs.getGroupingSeparator()) + "}";
decimalSeparator = "\\x{" + Integer.toHexString(dfs.getDecimalSeparator()) + "}";
// Quoting the nonzero length locale-specific things
// to avoid potential conflict with metacharacters
nanString = Pattern.quote(dfs.getNaN());
infinityString = Pattern.quote(dfs.getInfinity());
positivePrefix = df.getPositivePrefix();
if (!positivePrefix.isEmpty())
positivePrefix = Pattern.quote(positivePrefix);
negativePrefix = df.getNegativePrefix();
if (!negativePrefix.isEmpty())
negativePrefix = Pattern.quote(negativePrefix);
positiveSuffix = df.getPositiveSuffix();
if (!positiveSuffix.isEmpty())
positiveSuffix = Pattern.quote(positiveSuffix);
negativeSuffix = df.getNegativeSuffix();
if (!negativeSuffix.isEmpty())
negativeSuffix = Pattern.quote(negativeSuffix);
// Force rebuilding and recompilation of locale dependent
// primitive patterns
integerPattern = null;
floatPattern = null;
return this;
}
/**
* Returns this scanner's default radix.
*
* A scanner's radix affects elements of its default
* number matching regular expressions; see
* localized numbers above.
*
* @return the default radix of this scanner
*/
public int radix() {
return this.defaultRadix;
}
/**
* 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 {@link Character#MIN_RADIX Character.MIN_RADIX}
* or greater than {@link Character#MAX_RADIX Character.MAX_RADIX}, then an
* {@code IllegalArgumentException} is thrown.
*
* Invoking the {@link #reset} method will set the scanner's radix to
* {@code 10}.
*
* @param radix The radix to use when scanning numbers
* @return this scanner
* @throws IllegalArgumentException if radix is out of range
*/
public Scanner useRadix(int radix) {
if ((radix < Character.MIN_RADIX) || (radix > Character.MAX_RADIX))
throw new IllegalArgumentException("radix:"+radix);
if (this.defaultRadix == radix)
return this;
modCount++;
this.defaultRadix = radix;
// Force rebuilding and recompilation of radix dependent patterns
integerPattern = null;
return this;
}
// The next operation should occur in the specified radix but
// the default is left untouched.
private void setRadix(int radix) {
if ((radix < Character.MIN_RADIX) || (radix > Character.MAX_RADIX))
throw new IllegalArgumentException("radix:"+radix);
if (this.radix != radix) {
// Force rebuilding and recompilation of radix dependent patterns
integerPattern = null;
this.radix = radix;
}
}
/**
* Returns the match result of the last scanning operation performed
* by this scanner. This method throws {@code IllegalStateException}
* if no match has been performed, or if the last match was
* not successful.
*
* The various {@code next} methods of {@code Scanner}
* make a match result available if they complete without throwing an
* exception. For instance, after an invocation of the {@link #nextInt}
* method that returned an int, this method returns a
* {@code MatchResult} for the search of the
* Integer regular expression
* defined above. Similarly the {@link #findInLine findInLine()},
* {@link #findWithinHorizon findWithinHorizon()}, and {@link #skip skip()}
* methods will make a match available if they succeed.
*
* @return a match result for the last match operation
* @throws IllegalStateException If no match result is available
*/
public MatchResult match() {
if (!matchValid)
throw new IllegalStateException("No match result available");
return matcher.toMatchResult();
}
/**
* Returns the string representation of this {@code Scanner}. The
* string representation of a {@code Scanner} contains information
* that may be useful for debugging. The exact format is unspecified.
*
* @return The string representation of this scanner
*/
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("java.util.Scanner");
sb.append("[delimiters=" + delimPattern + "]");
sb.append("[position=" + position + "]");
sb.append("[match valid=" + matchValid + "]");
sb.append("[need input=" + needInput + "]");
sb.append("[source closed=" + sourceClosed + "]");
sb.append("[skipped=" + skipped + "]");
sb.append("[group separator=" + groupSeparator + "]");
sb.append("[decimal separator=" + decimalSeparator + "]");
sb.append("[positive prefix=" + positivePrefix + "]");
sb.append("[negative prefix=" + negativePrefix + "]");
sb.append("[positive suffix=" + positiveSuffix + "]");
sb.append("[negative suffix=" + negativeSuffix + "]");
sb.append("[NaN string=" + nanString + "]");
sb.append("[infinity string=" + infinityString + "]");
return sb.toString();
}
/**
* 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 true if and only if this scanner has another token
* @throws IllegalStateException if this scanner is closed
* @see java.util.Iterator
*/
public boolean hasNext() {
ensureOpen();
saveState();
modCount++;
while (!sourceClosed) {
if (hasTokenInBuffer()) {
return revertState(true);
}
readInput();
}
boolean result = hasTokenInBuffer();
return revertState(result);
}
/**
* 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 {@link #hasNext} returned
* {@code true}.
*
* @return the next token
* @throws NoSuchElementException if no more tokens are available
* @throws IllegalStateException if this scanner is closed
* @see java.util.Iterator
*/
public String next() {
ensureOpen();
clearCaches();
modCount++;
while (true) {
String token = getCompleteTokenInBuffer(null);
if (token != null) {
matchValid = true;
skipped = false;
return token;
}
if (needInput)
readInput();
else
throwFor();
}
}
/**
* The remove operation is not supported by this implementation of
* {@code Iterator}.
*
* @throws UnsupportedOperationException if this method is invoked.
* @see java.util.Iterator
*/
public void remove() {
throw new UnsupportedOperationException();
}
/**
* 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 {@code hasNext(pattern)}
* behaves in exactly the same way as the invocation
* {@code hasNext(Pattern.compile(pattern))}.
*
* @param pattern a string specifying the pattern to scan
* @return true if and only if this scanner has another token matching
* the specified pattern
* @throws IllegalStateException if this scanner is closed
*/
public boolean hasNext(String pattern) {
return hasNext(patternCache.forName(pattern));
}
/**
* Returns the next token if it matches the pattern constructed from the
* specified string. If the match is successful, the scanner advances
* past the input that matched the pattern.
*
* An invocation of this method of the form {@code next(pattern)}
* behaves in exactly the same way as the invocation
* {@code next(Pattern.compile(pattern))}.
*
* @param pattern a string specifying the pattern to scan
* @return the next token
* @throws NoSuchElementException if no such tokens are available
* @throws IllegalStateException if this scanner is closed
*/
public String next(String pattern) {
return next(patternCache.forName(pattern));
}
/**
* Returns true if the next complete token matches the specified pattern.
* A complete token is prefixed and postfixed by input that matches
* the delimiter pattern. This method may block while waiting for input.
* The scanner does not advance past any input.
*
* @param pattern the pattern to scan for
* @return true if and only if this scanner has another token matching
* the specified pattern
* @throws IllegalStateException if this scanner is closed
*/
public boolean hasNext(Pattern pattern) {
ensureOpen();
if (pattern == null)
throw new NullPointerException();
hasNextPattern = null;
saveState();
modCount++;
while (true) {
if (getCompleteTokenInBuffer(pattern) != null) {
matchValid = true;
cacheResult();
return revertState(true);
}
if (needInput)
readInput();
else
return revertState(false);
}
}
/**
* 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 {@link #hasNext(Pattern)} returned {@code true}.
* If the match is successful, the scanner advances past the input that
* matched the pattern.
*
* @param pattern the pattern to scan for
* @return the next token
* @throws NoSuchElementException if no more tokens are available
* @throws IllegalStateException if this scanner is closed
*/
public String next(Pattern pattern) {
ensureOpen();
if (pattern == null)
throw new NullPointerException();
modCount++;
// Did we already find this pattern?
if (hasNextPattern == pattern)
return getCachedResult();
clearCaches();
// Search for the pattern
while (true) {
String token = getCompleteTokenInBuffer(pattern);
if (token != null) {
matchValid = true;
skipped = false;
return token;
}
if (needInput)
readInput();
else
throwFor();
}
}
/**
* 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 true if and only if this scanner has another line of input
* @throws IllegalStateException if this scanner is closed
*/
public boolean hasNextLine() {
saveState();
modCount++;
String result = findWithinHorizon(linePattern(), 0);
if (result != null) {
MatchResult mr = this.match();
String lineSep = mr.group(1);
if (lineSep != null) {
result = result.substring(0, result.length() -
lineSep.length());
cacheResult(result);
} else {
cacheResult();
}
}
revertState();
return (result != null);
}
/**
* 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 the line that was skipped
* @throws NoSuchElementException if no line was found
* @throws IllegalStateException if this scanner is closed
*/
public String nextLine() {
modCount++;
if (hasNextPattern == linePattern())
return getCachedResult();
clearCaches();
String result = findWithinHorizon(linePattern, 0);
if (result == null)
throw new NoSuchElementException("No line found");
MatchResult mr = this.match();
String lineSep = mr.group(1);
if (lineSep != null)
result = result.substring(0, result.length() - lineSep.length());
if (result == null)
throw new NoSuchElementException();
else
return result;
}
// Public methods that ignore delimiters
/**
* Attempts to find the next occurrence of a pattern constructed from the
* specified string, ignoring delimiters.
*
* An invocation of this method of the form {@code findInLine(pattern)}
* behaves in exactly the same way as the invocation
* {@code findInLine(Pattern.compile(pattern))}.
*
* @param pattern a string specifying the pattern to search for
* @return the text that matched the specified pattern
* @throws IllegalStateException if this scanner is closed
*/
public String findInLine(String pattern) {
return findInLine(patternCache.forName(pattern));
}
/**
* Attempts to find the next occurrence of the specified pattern ignoring
* delimiters. If the pattern is found before the next line separator, the
* scanner advances past the input that matched and returns the string that
* matched the pattern.
* If no such pattern is detected in the input up to the next line
* separator, then {@code 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.
*
* @param pattern the pattern to scan for
* @return the text that matched the specified pattern
* @throws IllegalStateException if this scanner is closed
*/
public String findInLine(Pattern pattern) {
ensureOpen();
if (pattern == null)
throw new NullPointerException();
clearCaches();
modCount++;
// Expand buffer to include the next newline or end of input
int endPosition = 0;
saveState();
while (true) {
if (findPatternInBuffer(separatorPattern(), 0)) {
endPosition = matcher.start();
break; // up to next newline
}
if (needInput) {
readInput();
} else {
endPosition = buf.limit();
break; // up to end of input
}
}
revertState();
int horizonForLine = endPosition - position;
// If there is nothing between the current pos and the next
// newline simply return null, invoking findWithinHorizon
// with "horizon=0" will scan beyond the line bound.
if (horizonForLine == 0)
return null;
// Search for the pattern
return findWithinHorizon(pattern, horizonForLine);
}
/**
* Attempts to find the next occurrence of a pattern constructed from the
* specified string, ignoring delimiters.
*
* An invocation of this method of the form
* {@code findWithinHorizon(pattern)} behaves in exactly the same way as
* the invocation
* {@code findWithinHorizon(Pattern.compile(pattern), horizon)}.
*
* @param pattern a string specifying the pattern to search for
* @param horizon the search horizon
* @return the text that matched the specified pattern
* @throws IllegalStateException if this scanner is closed
* @throws IllegalArgumentException if horizon is negative
*/
public String findWithinHorizon(String pattern, int horizon) {
return findWithinHorizon(patternCache.forName(pattern), horizon);
}
/**
* Attempts to find the next occurrence of the specified pattern.
*
* This method searches through the input up to the specified
* search horizon, ignoring delimiters. If the pattern is found the
* scanner advances past the input that matched and returns the string
* that matched the pattern. If no such pattern is detected then the
* null is returned and the scanner's position remains unchanged. This
* method may block waiting for input that matches the pattern.
*
* A scanner will never search more than {@code 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 {@link
* Matcher#useTransparentBounds} and {@link Matcher#useAnchoringBounds}).
*
* If horizon is {@code 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.
*
* @param pattern the pattern to scan for
* @param horizon the search horizon
* @return the text that matched the specified pattern
* @throws IllegalStateException if this scanner is closed
* @throws IllegalArgumentException if horizon is negative
*/
public String findWithinHorizon(Pattern pattern, int horizon) {
ensureOpen();
if (pattern == null)
throw new NullPointerException();
if (horizon < 0)
throw new IllegalArgumentException("horizon < 0");
clearCaches();
modCount++;
// Search for the pattern
while (true) {
if (findPatternInBuffer(pattern, horizon)) {
matchValid = true;
return matcher.group();
}
if (needInput)
readInput();
else
break; // up to end of input
}
return null;
}
/**
* 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
* {@code 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
* {@code NoSuchElementException} by using a pattern that can
* match nothing, e.g., {@code sc.skip("[ \t]*")}.
*
* @param pattern a string specifying the pattern to skip over
* @return this scanner
* @throws NoSuchElementException if the specified pattern is not found
* @throws IllegalStateException if this scanner is closed
*/
public Scanner skip(Pattern pattern) {
ensureOpen();
if (pattern == null)
throw new NullPointerException();
clearCaches();
modCount++;
// Search for the pattern
while (true) {
if (matchPatternInBuffer(pattern)) {
matchValid = true;
position = matcher.end();
return this;
}
if (needInput)
readInput();
else
throw new NoSuchElementException();
}
}
/**
* Skips input that matches a pattern constructed from the specified
* string.
*
* An invocation of this method of the form {@code skip(pattern)}
* behaves in exactly the same way as the invocation
* {@code skip(Pattern.compile(pattern))}.
*
* @param pattern a string specifying the pattern to skip over
* @return this scanner
* @throws IllegalStateException if this scanner is closed
*/
public Scanner skip(String pattern) {
return skip(patternCache.forName(pattern));
}
// Convenience methods for scanning primitives
/**
* 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 true if and only if this scanner's next token is a valid
* boolean value
* @throws IllegalStateException if this scanner is closed
*/
public boolean hasNextBoolean() {
return hasNext(boolPattern());
}
/**
* Scans the next token of the input into a boolean value and returns
* that value. This method will throw {@code 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 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
*/
public boolean nextBoolean() {
clearCaches();
return Boolean.parseBoolean(next(boolPattern()));
}
/**
* Returns true if the next token in this scanner's input can be
* interpreted as a byte value in the default radix using the
* {@link #nextByte} method. The scanner does not advance past any input.
*
* @return true if and only if this scanner's next token is a valid
* byte value
* @throws IllegalStateException if this scanner is closed
*/
public boolean hasNextByte() {
return hasNextByte(defaultRadix);
}
/**
* Returns true if the next token in this scanner's input can be
* interpreted as a byte value in the specified radix using the
* {@link #nextByte} method. The scanner does not advance past any input.
*
* If the radix is less than {@link Character#MIN_RADIX Character.MIN_RADIX}
* or greater than {@link Character#MAX_RADIX Character.MAX_RADIX}, then an
* {@code IllegalArgumentException} is thrown.
*
* @param radix the radix used to interpret the token as a byte value
* @return true if and only if this scanner's next token is a valid
* byte value
* @throws IllegalStateException if this scanner is closed
* @throws IllegalArgumentException if the radix is out of range
*/
public boolean hasNextByte(int radix) {
setRadix(radix);
boolean result = hasNext(integerPattern());
if (result) { // Cache it
try {
String s = (matcher.group(SIMPLE_GROUP_INDEX) == null) ?
processIntegerToken(hasNextResult) :
hasNextResult;
typeCache = Byte.parseByte(s, radix);
} catch (NumberFormatException nfe) {
result = false;
}
}
return result;
}
/**
* Scans the next token of the input as a {@code byte}.
*
* An invocation of this method of the form
* {@code nextByte()} behaves in exactly the same way as the
* invocation {@code nextByte(radix)}, where {@code radix}
* is the default radix of this scanner.
*
* @return the {@code byte} scanned from the input
* @throws InputMismatchException
* if the next token does not match the Integer
* regular expression, or is out of range
* @throws NoSuchElementException if input is exhausted
* @throws IllegalStateException if this scanner is closed
*/
public byte nextByte() {
return nextByte(defaultRadix);
}
/**
* Scans the next token of the input as a {@code byte}.
* This method will throw {@code 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 {@code 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 {@link Character#digit Character.digit}, prepending a
* negative sign (-) if the locale specific negative prefixes and suffixes
* were present, and passing the resulting string to
* {@link Byte#parseByte(String, int) Byte.parseByte} with the
* specified radix.
*
* If the radix is less than {@link Character#MIN_RADIX Character.MIN_RADIX}
* or greater than {@link Character#MAX_RADIX Character.MAX_RADIX}, then an
* {@code IllegalArgumentException} is thrown.
*
* @param radix the radix used to interpret the token as a byte value
* @return the {@code byte} scanned from the input
* @throws InputMismatchException
* if the next token does not match the Integer
* regular expression, or is out of range
* @throws NoSuchElementException if input is exhausted
* @throws IllegalStateException if this scanner is closed
* @throws IllegalArgumentException if the radix is out of range
*/
public byte nextByte(int radix) {
// Check cached result
if ((typeCache != null) && (typeCache instanceof Byte)
&& this.radix == radix) {
byte val = ((Byte)typeCache).byteValue();
useTypeCache();
return val;
}
setRadix(radix);
clearCaches();
// Search for next byte
try {
String s = next(integerPattern());
if (matcher.group(SIMPLE_GROUP_INDEX) == null)
s = processIntegerToken(s);
return Byte.parseByte(s, radix);
} catch (NumberFormatException nfe) {
position = matcher.start(); // don't skip bad token
throw new InputMismatchException(nfe.getMessage());
}
}
/**
* Returns true if the next token in this scanner's input can be
* interpreted as a short value in the default radix using the
* {@link #nextShort} method. The scanner does not advance past any input.
*
* @return true if and only if this scanner's next token is a valid
* short value in the default radix
* @throws IllegalStateException if this scanner is closed
*/
public boolean hasNextShort() {
return hasNextShort(defaultRadix);
}
/**
* Returns true if the next token in this scanner's input can be
* interpreted as a short value in the specified radix using the
* {@link #nextShort} method. The scanner does not advance past any input.
*
* If the radix is less than {@link Character#MIN_RADIX Character.MIN_RADIX}
* or greater than {@link Character#MAX_RADIX Character.MAX_RADIX}, then an
* {@code IllegalArgumentException} is thrown.
*
* @param radix the radix used to interpret the token as a short value
* @return true if and only if this scanner's next token is a valid
* short value in the specified radix
* @throws IllegalStateException if this scanner is closed
* @throws IllegalArgumentException if the radix is out of range
*/
public boolean hasNextShort(int radix) {
setRadix(radix);
boolean result = hasNext(integerPattern());
if (result) { // Cache it
try {
String s = (matcher.group(SIMPLE_GROUP_INDEX) == null) ?
processIntegerToken(hasNextResult) :
hasNextResult;
typeCache = Short.parseShort(s, radix);
} catch (NumberFormatException nfe) {
result = false;
}
}
return result;
}
/**
* Scans the next token of the input as a {@code short}.
*
* An invocation of this method of the form
* {@code nextShort()} behaves in exactly the same way as the
* invocation {@link #nextShort(int) nextShort(radix)}, where {@code radix}
* is the default radix of this scanner.
*
* @return the {@code short} scanned from the input
* @throws InputMismatchException
* if the next token does not match the Integer
* regular expression, or is out of range
* @throws NoSuchElementException if input is exhausted
* @throws IllegalStateException if this scanner is closed
*/
public short nextShort() {
return nextShort(defaultRadix);
}
/**
* Scans the next token of the input as a {@code short}.
* This method will throw {@code 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 {@code 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 {@link Character#digit Character.digit}, prepending a
* negative sign (-) if the locale specific negative prefixes and suffixes
* were present, and passing the resulting string to
* {@link Short#parseShort(String, int) Short.parseShort} with the
* specified radix.
*
* If the radix is less than {@link Character#MIN_RADIX Character.MIN_RADIX}
* or greater than {@link Character#MAX_RADIX Character.MAX_RADIX}, then an
* {@code IllegalArgumentException} is thrown.
*
* @param radix the radix used to interpret the token as a short value
* @return the {@code short} scanned from the input
* @throws InputMismatchException
* if the next token does not match the Integer
* regular expression, or is out of range
* @throws NoSuchElementException if input is exhausted
* @throws IllegalStateException if this scanner is closed
* @throws IllegalArgumentException if the radix is out of range
*/
public short nextShort(int radix) {
// Check cached result
if ((typeCache != null) && (typeCache instanceof Short)
&& this.radix == radix) {
short val = ((Short)typeCache).shortValue();
useTypeCache();
return val;
}
setRadix(radix);
clearCaches();
// Search for next short
try {
String s = next(integerPattern());
if (matcher.group(SIMPLE_GROUP_INDEX) == null)
s = processIntegerToken(s);
return Short.parseShort(s, radix);
} catch (NumberFormatException nfe) {
position = matcher.start(); // don't skip bad token
throw new InputMismatchException(nfe.getMessage());
}
}
/**
* Returns true if the next token in this scanner's input can be
* interpreted as an int value in the default radix using the
* {@link #nextInt} method. The scanner does not advance past any input.
*
* @return true if and only if this scanner's next token is a valid
* int value
* @throws IllegalStateException if this scanner is closed
*/
public boolean hasNextInt() {
return hasNextInt(defaultRadix);
}
/**
* Returns true if the next token in this scanner's input can be
* interpreted as an int value in the specified radix using the
* {@link #nextInt} method. The scanner does not advance past any input.
*
* If the radix is less than {@link Character#MIN_RADIX Character.MIN_RADIX}
* or greater than {@link Character#MAX_RADIX Character.MAX_RADIX}, then an
* {@code IllegalArgumentException} is thrown.
*
* @param radix the radix used to interpret the token as an int value
* @return true if and only if this scanner's next token is a valid
* int value
* @throws IllegalStateException if this scanner is closed
* @throws IllegalArgumentException if the radix is out of range
*/
public boolean hasNextInt(int radix) {
setRadix(radix);
boolean result = hasNext(integerPattern());
if (result) { // Cache it
try {
String s = (matcher.group(SIMPLE_GROUP_INDEX) == null) ?
processIntegerToken(hasNextResult) :
hasNextResult;
typeCache = Integer.parseInt(s, radix);
} catch (NumberFormatException nfe) {
result = false;
}
}
return result;
}
/**
* The integer token must be stripped of prefixes, group separators,
* and suffixes, non ascii digits must be converted into ascii digits
* before parse will accept it.
*/
private String processIntegerToken(String token) {
String result = token.replaceAll(""+groupSeparator, "");
boolean isNegative = false;
int preLen = negativePrefix.length();
if ((preLen > 0) && result.startsWith(negativePrefix)) {
isNegative = true;
result = result.substring(preLen);
}
int sufLen = negativeSuffix.length();
if ((sufLen > 0) && result.endsWith(negativeSuffix)) {
isNegative = true;
result = result.substring(result.length() - sufLen,
result.length());
}
if (isNegative)
result = "-" + result;
return result;
}
/**
* Scans the next token of the input as an {@code int}.
*
* An invocation of this method of the form
* {@code nextInt()} behaves in exactly the same way as the
* invocation {@code nextInt(radix)}, where {@code radix}
* is the default radix of this scanner.
*
* @return the {@code int} scanned from the input
* @throws InputMismatchException
* if the next token does not match the Integer
* regular expression, or is out of range
* @throws NoSuchElementException if input is exhausted
* @throws IllegalStateException if this scanner is closed
*/
public int nextInt() {
return nextInt(defaultRadix);
}
/**
* Scans the next token of the input as an {@code int}.
* This method will throw {@code 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 {@code 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 {@link Character#digit Character.digit}, prepending a
* negative sign (-) if the locale specific negative prefixes and suffixes
* were present, and passing the resulting string to
* {@link Integer#parseInt(String, int) Integer.parseInt} with the
* specified radix.
*
* If the radix is less than {@link Character#MIN_RADIX Character.MIN_RADIX}
* or greater than {@link Character#MAX_RADIX Character.MAX_RADIX}, then an
* {@code IllegalArgumentException} is thrown.
*
* @param radix the radix used to interpret the token as an int value
* @return the {@code int} scanned from the input
* @throws InputMismatchException
* if the next token does not match the Integer
* regular expression, or is out of range
* @throws NoSuchElementException if input is exhausted
* @throws IllegalStateException if this scanner is closed
* @throws IllegalArgumentException if the radix is out of range
*/
public int nextInt(int radix) {
// Check cached result
if ((typeCache != null) && (typeCache instanceof Integer)
&& this.radix == radix) {
int val = ((Integer)typeCache).intValue();
useTypeCache();
return val;
}
setRadix(radix);
clearCaches();
// Search for next int
try {
String s = next(integerPattern());
if (matcher.group(SIMPLE_GROUP_INDEX) == null)
s = processIntegerToken(s);
return Integer.parseInt(s, radix);
} catch (NumberFormatException nfe) {
position = matcher.start(); // don't skip bad token
throw new InputMismatchException(nfe.getMessage());
}
}
/**
* Returns true if the next token in this scanner's input can be
* interpreted as a long value in the default radix using the
* {@link #nextLong} method. The scanner does not advance past any input.
*
* @return true if and only if this scanner's next token is a valid
* long value
* @throws IllegalStateException if this scanner is closed
*/
public boolean hasNextLong() {
return hasNextLong(defaultRadix);
}
/**
* Returns true if the next token in this scanner's input can be
* interpreted as a long value in the specified radix using the
* {@link #nextLong} method. The scanner does not advance past any input.
*
* If the radix is less than {@link Character#MIN_RADIX Character.MIN_RADIX}
* or greater than {@link Character#MAX_RADIX Character.MAX_RADIX}, then an
* {@code IllegalArgumentException} is thrown.
*
* @param radix the radix used to interpret the token as a long value
* @return true if and only if this scanner's next token is a valid
* long value
* @throws IllegalStateException if this scanner is closed
* @throws IllegalArgumentException if the radix is out of range
*/
public boolean hasNextLong(int radix) {
setRadix(radix);
boolean result = hasNext(integerPattern());
if (result) { // Cache it
try {
String s = (matcher.group(SIMPLE_GROUP_INDEX) == null) ?
processIntegerToken(hasNextResult) :
hasNextResult;
typeCache = Long.parseLong(s, radix);
} catch (NumberFormatException nfe) {
result = false;
}
}
return result;
}
/**
* Scans the next token of the input as a {@code long}.
*
* An invocation of this method of the form
* {@code nextLong()} behaves in exactly the same way as the
* invocation {@code nextLong(radix)}, where {@code radix}
* is the default radix of this scanner.
*
* @return the {@code long} scanned from the input
* @throws InputMismatchException
* if the next token does not match the Integer
* regular expression, or is out of range
* @throws NoSuchElementException if input is exhausted
* @throws IllegalStateException if this scanner is closed
*/
public long nextLong() {
return nextLong(defaultRadix);
}
/**
* Scans the next token of the input as a {@code long}.
* This method will throw {@code 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 {@code 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 {@link Character#digit Character.digit}, prepending a
* negative sign (-) if the locale specific negative prefixes and suffixes
* were present, and passing the resulting string to
* {@link Long#parseLong(String, int) Long.parseLong} with the
* specified radix.
*
* If the radix is less than {@link Character#MIN_RADIX Character.MIN_RADIX}
* or greater than {@link Character#MAX_RADIX Character.MAX_RADIX}, then an
* {@code IllegalArgumentException} is thrown.
*
* @param radix the radix used to interpret the token as an int value
* @return the {@code long} scanned from the input
* @throws InputMismatchException
* if the next token does not match the Integer
* regular expression, or is out of range
* @throws NoSuchElementException if input is exhausted
* @throws IllegalStateException if this scanner is closed
* @throws IllegalArgumentException if the radix is out of range
*/
public long nextLong(int radix) {
// Check cached result
if ((typeCache != null) && (typeCache instanceof Long)
&& this.radix == radix) {
long val = ((Long)typeCache).longValue();
useTypeCache();
return val;
}
setRadix(radix);
clearCaches();
try {
String s = next(integerPattern());
if (matcher.group(SIMPLE_GROUP_INDEX) == null)
s = processIntegerToken(s);
return Long.parseLong(s, radix);
} catch (NumberFormatException nfe) {
position = matcher.start(); // don't skip bad token
throw new InputMismatchException(nfe.getMessage());
}
}
/**
* The float token must be stripped of prefixes, group separators,
* and suffixes, non ascii digits must be converted into ascii digits
* before parseFloat will accept it.
*
* If there are non-ascii digits in the token these digits must
* be processed before the token is passed to parseFloat.
*/
private String processFloatToken(String token) {
String result = token.replaceAll(groupSeparator, "");
if (!decimalSeparator.equals("\\."))
result = result.replaceAll(decimalSeparator, ".");
boolean isNegative = false;
int preLen = negativePrefix.length();
if ((preLen > 0) && result.startsWith(negativePrefix)) {
isNegative = true;
result = result.substring(preLen);
}
int sufLen = negativeSuffix.length();
if ((sufLen > 0) && result.endsWith(negativeSuffix)) {
isNegative = true;
result = result.substring(result.length() - sufLen,
result.length());
}
if (result.equals(nanString))
result = "NaN";
if (result.equals(infinityString))
result = "Infinity";
// BEGIN Android-added: Match the infinity symbol.
if (result.equals("\u221E"))
result = "Infinity";
// END Android-added: Match the infinity symbol.
if (isNegative)
result = "-" + result;
// Translate non-ASCII digits
Matcher m = NON_ASCII_DIGIT.matcher(result);
if (m.find()) {
StringBuilder inASCII = new StringBuilder();
for (int i=0; i If the next token matches the Float regular expression defined above
* then the token is converted into a {@code 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 {@link Character#digit Character.digit}, prepending a
* negative sign (-) if the locale specific negative prefixes and suffixes
* were present, and passing the resulting string to
* {@link Double#parseDouble Double.parseDouble}. If the token matches
* the localized NaN or infinity strings, then either "Nan" or "Infinity"
* is passed to {@link Double#parseDouble(String) Double.parseDouble} as
* appropriate.
*
* @return the {@code double} scanned from the input
* @throws InputMismatchException
* if the next token does not match the Float
* regular expression, or is out of range
* @throws NoSuchElementException if the input is exhausted
* @throws IllegalStateException if this scanner is closed
*/
public double nextDouble() {
// Check cached result
if ((typeCache != null) && (typeCache instanceof Double)) {
double val = ((Double)typeCache).doubleValue();
useTypeCache();
return val;
}
setRadix(10);
clearCaches();
// Search for next float
try {
return Double.parseDouble(processFloatToken(next(floatPattern())));
} catch (NumberFormatException nfe) {
position = matcher.start(); // don't skip bad token
throw new InputMismatchException(nfe.getMessage());
}
}
// Convenience methods for scanning multi precision numbers
/**
* Returns true if the next token in this scanner's input can be
* interpreted as a {@code BigInteger} in the default radix using the
* {@link #nextBigInteger} method. The scanner does not advance past any
* input.
*
* @return true if and only if this scanner's next token is a valid
* {@code BigInteger}
* @throws IllegalStateException if this scanner is closed
*/
public boolean hasNextBigInteger() {
return hasNextBigInteger(defaultRadix);
}
/**
* Returns true if the next token in this scanner's input can be
* interpreted as a {@code BigInteger} in the specified radix using
* the {@link #nextBigInteger} method. The scanner does not advance past
* any input.
*
* If the radix is less than {@link Character#MIN_RADIX Character.MIN_RADIX}
* or greater than {@link Character#MAX_RADIX Character.MAX_RADIX}, then an
* {@code IllegalArgumentException} is thrown.
*
* @param radix the radix used to interpret the token as an integer
* @return true if and only if this scanner's next token is a valid
* {@code BigInteger}
* @throws IllegalStateException if this scanner is closed
* @throws IllegalArgumentException if the radix is out of range
*/
public boolean hasNextBigInteger(int radix) {
setRadix(radix);
boolean result = hasNext(integerPattern());
if (result) { // Cache it
try {
String s = (matcher.group(SIMPLE_GROUP_INDEX) == null) ?
processIntegerToken(hasNextResult) :
hasNextResult;
typeCache = new BigInteger(s, radix);
} catch (NumberFormatException nfe) {
result = false;
}
}
return result;
}
/**
* Scans the next token of the input as a {@link java.math.BigInteger
* BigInteger}.
*
* An invocation of this method of the form
* {@code nextBigInteger()} behaves in exactly the same way as the
* invocation {@code nextBigInteger(radix)}, where {@code radix}
* is the default radix of this scanner.
*
* @return the {@code BigInteger} scanned from the input
* @throws InputMismatchException
* if the next token does not match the Integer
* regular expression, or is out of range
* @throws NoSuchElementException if the input is exhausted
* @throws IllegalStateException if this scanner is closed
*/
public BigInteger nextBigInteger() {
return nextBigInteger(defaultRadix);
}
/**
* Scans the next token of the input as a {@link java.math.BigInteger
* BigInteger}.
*
* If the next token matches the Integer regular expression defined
* above then the token is converted into a {@code BigInteger} value as if
* by removing all group separators, mapping non-ASCII digits into ASCII
* digits via the {@link Character#digit Character.digit}, and passing the
* resulting string to the {@link
* java.math.BigInteger#BigInteger(java.lang.String)
* BigInteger(String, int)} constructor with the specified radix.
*
* If the radix is less than {@link Character#MIN_RADIX Character.MIN_RADIX}
* or greater than {@link Character#MAX_RADIX Character.MAX_RADIX}, then an
* {@code IllegalArgumentException} is thrown.
*
* @param radix the radix used to interpret the token
* @return the {@code BigInteger} scanned from the input
* @throws InputMismatchException
* if the next token does not match the Integer
* regular expression, or is out of range
* @throws NoSuchElementException if the input is exhausted
* @throws IllegalStateException if this scanner is closed
* @throws IllegalArgumentException if the radix is out of range
*/
public BigInteger nextBigInteger(int radix) {
// Check cached result
if ((typeCache != null) && (typeCache instanceof BigInteger val)
&& this.radix == radix) {
useTypeCache();
return val;
}
setRadix(radix);
clearCaches();
// Search for next int
try {
String s = next(integerPattern());
if (matcher.group(SIMPLE_GROUP_INDEX) == null)
s = processIntegerToken(s);
return new BigInteger(s, radix);
} catch (NumberFormatException nfe) {
position = matcher.start(); // don't skip bad token
throw new InputMismatchException(nfe.getMessage());
}
}
/**
* Returns true if the next token in this scanner's input can be
* interpreted as a {@code BigDecimal} using the
* {@link #nextBigDecimal} method. The scanner does not advance past any
* input.
*
* @return true if and only if this scanner's next token is a valid
* {@code BigDecimal}
* @throws IllegalStateException if this scanner is closed
*/
public boolean hasNextBigDecimal() {
setRadix(10);
boolean result = hasNext(decimalPattern());
if (result) { // Cache it
try {
String s = processFloatToken(hasNextResult);
typeCache = new BigDecimal(s);
} catch (NumberFormatException nfe) {
result = false;
}
}
return result;
}
/**
* Scans the next token of the input as a {@link java.math.BigDecimal
* BigDecimal}.
*
* If the next token matches the Decimal regular expression defined
* above then the token is converted into a {@code BigDecimal} value as if
* by removing all group separators, mapping non-ASCII digits into ASCII
* digits via the {@link Character#digit Character.digit}, and passing the
* resulting string to the {@link
* java.math.BigDecimal#BigDecimal(java.lang.String) BigDecimal(String)}
* constructor.
*
* @return the {@code BigDecimal} scanned from the input
* @throws InputMismatchException
* if the next token does not match the Decimal
* regular expression, or is out of range
* @throws NoSuchElementException if the input is exhausted
* @throws IllegalStateException if this scanner is closed
*/
public BigDecimal nextBigDecimal() {
// Check cached result
if ((typeCache != null) && (typeCache instanceof BigDecimal val)) {
useTypeCache();
return val;
}
setRadix(10);
clearCaches();
// Search for next float
try {
String s = processFloatToken(next(decimalPattern()));
return new BigDecimal(s);
} catch (NumberFormatException nfe) {
position = matcher.start(); // don't skip bad token
throw new InputMismatchException(nfe.getMessage());
}
}
/**
* Resets this scanner.
*
* Resetting a scanner discards all of its explicit state
* information which may have been changed by invocations of
* {@link #useDelimiter useDelimiter()},
* {@link #useLocale useLocale()}, or
* {@link #useRadix useRadix()}.
*
* An invocation of this method of the form
* {@code scanner.reset()} behaves in exactly the same way as the
* invocation
*
* 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 {@link #close} and {@link #ioException} may return undefined results
* or may cause undefined effects on the returned stream. The returned stream's source
* {@code Spliterator} is fail-fast and will, on a best-effort basis, throw a
* {@link 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 {@link #close} method, or by
* closing the returned stream. Closing the stream will close the underlying scanner.
* {@code 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.
*
* @apiNote
* For example, the following code will create a list of
* comma-delimited tokens from a string:
*
* The resulting list would contain {@code "abc"}, {@code "def"},
* the empty string, and {@code "ghi"}.
*
* @return a sequential stream of token strings
* @throws IllegalStateException if this scanner is closed
* @since 9
*/
public Stream 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 {@link #close} and {@link #ioException} may return undefined results
* or may cause undefined effects on the returned stream. The returned stream's source
* {@code Spliterator} is fail-fast and will, on a best-effort basis, throw a
* {@link 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 {@link #close} method, or by
* closing the returned stream. Closing the stream will close the underlying scanner.
* {@code 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 {@link #findWithinHorizon findWithinHorizon()} methods, this method
* might block waiting for additional input, and it might buffer an unbounded amount of
* input searching for a match.
*
* @apiNote
* For example, the following code will read a file and return a list
* of all sequences of characters consisting of seven or more Latin capital
* letters:
*
*
*
* @return this scanner
*
* @since 1.6
*/
public Scanner reset() {
delimPattern = WHITESPACE_PATTERN;
useLocale(Locale.getDefault(Locale.Category.FORMAT));
useRadix(10);
clearCaches();
modCount++;
return this;
}
/**
* 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 {@link #next} method
* repeatedly until the {@link #hasNext} method returns false.
*
* {@code
* scanner.useDelimiter("\\p{javaWhitespace}+")
* .useLocale(Locale.getDefault(Locale.Category.FORMAT))
* .useRadix(10);
* }{@code
* List
*
* {@code
* try (Scanner sc = new Scanner(Path.of("input.txt"))) {
* Pattern pat = Pattern.compile("[A-Z]{7,}");
* List
*
* @param pattern the pattern to be matched
* @return a sequential stream of match results
* @throws NullPointerException if pattern is null
* @throws IllegalStateException if this scanner is closed
* @since 9
*/
public Stream{@code
* scanner.findAll(Pattern.compile(patString))
* }
*
* @param patString the pattern string
* @return a sequential stream of match results
* @throws NullPointerException if patString is null
* @throws IllegalStateException if this scanner is closed
* @throws PatternSyntaxException if the regular expression's syntax is invalid
* @since 9
* @see java.util.regex.Pattern
*/
public Stream