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Posted to commits@harmony.apache.org by te...@apache.org on 2006/07/08 23:17:12 UTC

svn commit: r420193 [1/2] - in /incubator/harmony/enhanced/classlib/trunk/modules/luni/src: main/java/java/util/Scanner.java test/java/tests/api/java/util/ScannerTest.java

Author: tellison
Date: Sat Jul  8 14:17:12 2006
New Revision: 420193

URL: http://svn.apache.org/viewvc?rev=420193&view=rev
Log:
Apply patch HARMONY-800 (Implementation of new methods findWithinHorizon(Pattern, int) in java.util.Scanner)

Modified:
    incubator/harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/util/Scanner.java
    incubator/harmony/enhanced/classlib/trunk/modules/luni/src/test/java/tests/api/java/util/ScannerTest.java

Modified: incubator/harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/util/Scanner.java
URL: http://svn.apache.org/viewvc/incubator/harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/util/Scanner.java?rev=420193&r1=420192&r2=420193&view=diff
==============================================================================
--- incubator/harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/util/Scanner.java (original)
+++ incubator/harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/util/Scanner.java Sat Jul  8 14:17:12 2006
@@ -1,994 +1,1059 @@
-/* Copyright 2006 The Apache Software Foundation or its licensors, as applicable
- * 
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package java.util;
-
-import java.io.Closeable;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.io.StringReader;
-import java.io.UnsupportedEncodingException;
-import java.math.BigDecimal;
-import java.math.BigInteger;
-import java.nio.CharBuffer;
-import java.nio.channels.Channels;
-import java.nio.channels.ReadableByteChannel;
-import java.nio.charset.Charset;
-import java.text.DecimalFormat;
-import java.text.NumberFormat;
-import java.util.regex.MatchResult;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-
-import org.apache.harmony.luni.util.NotYetImplementedException;
-
-/**
- * A parser that parses a text string to primitive types with the help of
- * regular expression. It supports localized number and various radixes.
- * 
- * The input is broken into tokens by the delimiter pattern, which is whitespace
- * by default. The primitive types can be got via corresponding next methods. If
- * the token is not in valid format, an InputMissmatchException is thrown.
- * 
- * For example: Scanner s = new Scanner("1A true");
- * System.out.println(s.nextInt(16)); System.out.println(s.nextBoolean()); The
- * result: 26 true
- * 
- * A scanner can find or skip specific pattern with no regard to the delimiter.
- * All these methods and the various next and hasNext methods may block.
- * 
- * Scanner is not thread-safe without external synchronization
- */
-public final class Scanner implements Iterator<String> {
-
-    //  Default delimiting pattern
-    private static final Pattern DEFAULT_DELIMITER = Pattern
-            .compile("\\p{javaWhitespace}+"); //$NON-NLS-1$
-    
-    //The boolean's pattern
-    private static final Pattern BOOLEAN_PATTERN = Pattern.compile(
-            "true|false", Pattern.CASE_INSENSITIVE); //$NON-NLS-1$
-    
-    // The pattern matching anything
-    private static final Pattern ANY_PATTERN = Pattern.compile("(?s).*");
-
-    private static final int DIPLOID = 2;
-
-    // Default radix
-    private static final int DEFAULT_RADIX = 10;
-
-    private static final int DEFAULT_TRUNK_SIZE = 1024;
-
-    // The input source of scanner
-    private Readable input;
-
-    private CharBuffer buffer;
-
-    private Pattern delimiter = DEFAULT_DELIMITER;
-
-    private Matcher matcher;
-
-    private int radix = DEFAULT_RADIX;
-
-    private Locale locale = Locale.getDefault();
-
-    // The position where find begins
-    private int findStartIndex = 0;
-
-    // The last find start position
-    private int preStartIndex = findStartIndex;
-
-    // The length of the buffer
-    private int bufferLength = 0;
-
-    // Used by find and nextXXX operation
-    private boolean closed = false;
-
-    private IOException lastIOException;
-    
-    private boolean matchSuccessful = false;
-
-    /**
-     * Constructs a scanner that uses File as its input. The default charset is
-     * applied when reading the file.
-     * 
-     * @param src
-     *            the file to be scanned
-     * @throws FileNotFoundException
-     *             if the specified file is not found
-     */
-    public Scanner(File src) throws FileNotFoundException {
-        this(src, Charset.defaultCharset().name());
-    }
-
-    /**
-     * Constructs a scanner that uses File as its input. The specified charset
-     * is applied when reading the file.
-     * 
-     * @param src
-     *            the file to be scanned
-     * @param charsetName
-     *            the name of the encoding type of the file
-     * @throws FileNotFoundException
-     *             if the specified file is not found
-     * @throws IllegalArgumentException
-     *            if the specified coding does not exist
-     */
-    public Scanner(File src, String charsetName) throws FileNotFoundException {
-        if (null == src) {
-            throw new NullPointerException(org.apache.harmony.luni.util.Msg
-                    .getString("KA00a"));
-        }
-        FileInputStream fis = new FileInputStream(src);
-        if (null == charsetName) {
-            throw new IllegalArgumentException(org.apache.harmony.luni.util.Msg
-                    .getString("KA009"));
-        }
-        try {
-            input = new InputStreamReader(fis, charsetName);
-        } catch (UnsupportedEncodingException e) {
-            try {
-                fis.close();
-            } catch (IOException ioException) {
-                // ignore
-            }
-            throw new IllegalArgumentException(e.getMessage());
-        }
-        initialization();
-    }
-
-    /**
-     * Constructs a scanner that uses String as its input.
-     * 
-     * @param src
-     *            the string to be scanned
-     */
-    public Scanner(String src) {
-        input = new StringReader(src);
-        initialization();
-    }
-
-    /**
-     * Constructs a scanner that uses InputStream as its input. The default
-     * charset is applied when decoding the input.
-     * 
-     * @param src
-     *            the input stream to be scanned
-     */
-    public Scanner(InputStream src) {
-        this(src, Charset.defaultCharset().name());
-    }
-
-    /**
-     * Constructs a scanner that uses InputStream as its input. The specified
-     * charset is applied when decoding the input.
-     * 
-     * @param src
-     *            the input stream to be scanned
-     * @param charsetName
-     *            the encoding type of the input stream
-     * @throws IllegalArgumentException
-     *            if the specified character set is not found
-     */
-    public Scanner(InputStream src, String charsetName) {
-        if (null == src) {
-            throw new NullPointerException(org.apache.harmony.luni.util.Msg
-                    .getString("KA00b"));
-        }
-        try {
-            input = new InputStreamReader(src, charsetName);
-        } catch (UnsupportedEncodingException e) {
-            throw new IllegalArgumentException(e.getMessage());
-        }
-        initialization();
-    }
-
-    /**
-     * Constructs a scanner that uses Readable as its input.
-     * 
-     * @param src
-     *            the Readable to be scanned
-     */
-    public Scanner(Readable src) {
-        if (null == src) {
-            throw new NullPointerException();
-        }
-        input = src;
-        initialization();
-    }
-
-    /**
-     * Constructs a scanner that uses ReadableByteChannel as its input. The
-     * default charset is applied when decoding the input.
-     * 
-     * @param src
-     *            the ReadableByteChannel to be scanned
-     */
-    public Scanner(ReadableByteChannel src) {
-        this(src, Charset.defaultCharset().name());
-    }
-
-    /**
-     * Constructs a scanner that uses ReadableByteChannel as its input. The
-     * specified charset is applied when decoding the input.
-     * 
-     * @param src
-     *            the ReadableByteChannel to be scanned
-     * @param charsetName
-     *            the encoding type of the content in the ReadableByteChannel
-     * @throws IllegalArgumentException
-     *            if the specified character set is not found           
-     */
-    public Scanner(ReadableByteChannel src, String charsetName) {
-        if (null == src) {
-            throw new NullPointerException(org.apache.harmony.luni.util.Msg
-                    .getString("KA00d"));
-        }
-        if (null == charsetName) {
-            throw new IllegalArgumentException(org.apache.harmony.luni.util.Msg
-                    .getString("KA009"));
-        }
-        try {
-            input = new InputStreamReader(Channels.newInputStream(src),
-                    charsetName);
-        } catch (UnsupportedEncodingException e) {
-            throw new IllegalArgumentException(e.getMessage());
-        }
-        initialization();
-    }
-
-    /**
-     * Closes the underlying input if the input implements Closeable. If the
-     * scanner has been closed, this method will take no effect. The scanning
-     * operation after calling this method will throw IllegalStateException
-     * 
-     */
-    public void close() {
-        if (closed == true) {
-            return;
-        }
-        if (input instanceof Closeable) {
-            try {
-                ((Closeable) input).close();
-            } catch (IOException e) {
-                lastIOException = e;
-            }
-        }
-        closed = true;
-    }
-
-    /**
-     * Returns the <code>Pattern</code> in use by this scanner.
-     * 
-     * @return the <code>Pattern</code> presently in use by this scanner
-     */
-    public Pattern delimiter() {
-        return delimiter;
-    }
-
-    //TODO: To implement this feature
-    public String findInLine(Pattern pattern) {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public String findInLine(String pattern) {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public String findWithinHorizon(Pattern pattern, int horizon) {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public String findWithinHorizon(String pattern, int horizon) {
-        throw new NotYetImplementedException();
-    }
-
-    /**
-     * Returns true if this scanner has next token. This method may be blocked
-     * when it is waiting for input to scan. This scanner does not advance past
-     * the input.
-     * 
-     * @return true 
-     *             iff this scanner has next token
-     * @throws IllegalStateException
-     *             if the scanner has been closed
-     */
-    public boolean hasNext() {
-        return hasNext(ANY_PATTERN);
-    }
-
-    /**
-     * Returns true if this scanner's next token matches the specified pattern.
-     * This method may be blocked when it is waiting for input to scan. This
-     * scanner does not advance past the input that matched the pattern.
-     * 
-     * @param pattern
-     *            the specified pattern to scan
-     * @return 
-     *            true iff this scanner's next token matches the specified pattern
-     * @throws IllegalStateException
-     *            if the scanner has been closed
-     */
-    public boolean hasNext(Pattern pattern) {
-        checkClosed();
-        if (isInputExhausted()) {
-            return false;
-        }
-        saveCurrentStatus();
-        //if the next token exists, set the match region, otherwise return false
-        if (!setTokenRegion()) {
-            recoverPreviousStatus();
-            return false;
-        }
-        matcher.usePattern(pattern);
-        boolean hasNext = false;
-        //check whether next token matches the specified pattern
-        if (matcher.matches()) {
-            hasNext = true;
-        }
-        recoverPreviousStatus();
-        return hasNext;
-    }
-
-
-    /**
-     * Returns true if this scanner's next token matches the pattern constructed
-     * from the specified string. This method may be blocked when it is waiting
-     * for input to scan. This scanner does not advance past the input that
-     * matched the pattern.
-     * 
-     * The invocation of this method in the form hasNext(pattern) behaves in the
-     * same way as the invocaiton of hasNext(Pattern.compile(pattern)).
-     * 
-     * @param pattern
-     *            the string specifying the pattern to scan for
-     * @return true 
-     *            iff this scanner's next token matches the specified pattern
-     * @throws IllegalStateException
-     *             if the scanner has been closed
-     */
-    public boolean hasNext(String pattern) {
-        return hasNext(Pattern.compile(pattern));
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextBigDecimal() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextBigInteger() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextBigInteger(int radix) {
-        throw new NotYetImplementedException();
-    }
-
-    /**
-     * Returns true if this scanner's next token can be translated into a valid
-     * boolean value. The scanner does not advance past the input that matched.
-     * 
-     * @return true 
-     *             iff the next token in this scanner's input can be translated
-     *         into a valid boolean value
-     * @throws IllegalStateException
-     *             if the scanner has been closed
-     */
-    public boolean hasNextBoolean() {
-        return hasNext(BOOLEAN_PATTERN);
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextByte() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextByte(int radix) {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextDouble() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextFloat() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextInt() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextInt(int radix) {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextLine() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextLong() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextLong(int radix) {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextShort() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public boolean hasNextShort(int radix) {
-        throw new NotYetImplementedException();
-    }
-
-    /**
-     * returns the last IOException thrown when reading the underlying input. If
-     * no exception is thrown, return null.
-     * 
-     * @return the last IOException thrown
-     */
-    public IOException ioException() {
-        return lastIOException;
-    }
-
-    /**
-     * return the locale of this scanner.
-     * 
-     * @return 
-     *             the locale of this scanner
-     */
-    public Locale locale() {
-        return locale;
-    }
-
-    /**
-     * Returns the match result of this scanner's last match operation.This
-     * method throws IllegalStateException if no match operation has been
-     * performed, or if the last match was unsuccessful.
-     * 
-     * The various nextXXX methods of Scanner provide a match result if they do
-     * not complete with throwing an exception. For example, after an invocation
-     * of the nextBoolean() method which returned a boolean value, this method
-     * returns a match result for the search of the Boolean regular expression
-     * defined above. In the same way,the findInLine(java.lang.String),
-     * findWithinHorizon(java.lang.String, int), and
-     * skip(java.util.regex.Pattern) methods will provide a match result if they
-     * are successful.
-     * 
-     * @return the match result of the last match operation
-     * @throws IllegalStateException
-     *             if the match result is available
-     */
-    public MatchResult match() {
-        if (!matchSuccessful) {
-            throw new IllegalStateException();
-        }
-        return matcher.toMatchResult();
-    }
-
-    /**
-     * Finds and Returns the next complete token which is prefixed and postfixed
-     * by input that matches the delimiter pattern. This method may be blocked
-     * when it is waiting for input to scan, even if a previous invocation of
-     * hasNext() returned true. If this match successes, the scanner advances
-     * past the next complete token.
-     * 
-     * @return 
-     *             the next complete token
-     * @throws IllegalStateException
-     *             if this scanner has been closed
-     * @throws NoSuchElementException
-     *             if input has been exhausted
-     */
-    public String next() {
-        return next(ANY_PATTERN);
-    }
-
-    /**
-     * Returns the next token which is prefixed and postfixed by input that
-     * matches the delimiter pattern if this token matches the specified
-     * pattern. This method may be blocked when it is waiting for input to scan,
-     * even if a previous invocation of hasNext(Pattern) returned true. If this
-     * match successes, the scanner advances past the next token that matched
-     * the pattern.
-     * 
-     * @param pattern
-     *            the specified pattern to scan
-     * @return 
-     *             the next token
-     * @throws IllegalStateException
-     *             if this scanner has been closed
-     * @throws NoSuchElementException
-     *             if input has been exhausted
-     */
-    public String next(Pattern pattern) {
-        checkClosed();
-        if (null == pattern) {
-            throw new NullPointerException();
-        }
-        matchSuccessful = false;
-        if (isInputExhausted()) {
-            throw new NoSuchElementException();
-        }
-        saveCurrentStatus();
-        if (!setTokenRegion()) {
-            recoverPreviousStatus();
-            // if setting match region fails
-            throw new NoSuchElementException();
-        }
-        matcher.usePattern(pattern);
-        if (matchSuccessful = matcher.matches()) {
-            return matcher.group(0);
-        } else {
-            recoverPreviousStatus();
-            throw new InputMismatchException();
-        }
-    }
-
-    /**
-     * Returns the next token which is prefixed and postfixed by input that
-     * matches the delimiter pattern if this token matches the pattern
-     * constructed from the sepcified string. This method may be blocked when it
-     * is waiting for input to scan. If this match successes, the scanner
-     * advances past the next token that matched the pattern.
-     * 
-     * The invocation of this method in the form next(pattern) behaves in the
-     * same way as the invocaiton of next(Pattern.compile(pattern)).
-     * 
-     * @param pattern
-     *            the string specifying the pattern to scan for
-     * @return 
-     *             the next token
-     * @throws IllegalStateException
-     *             if this scanner has been closed
-     * @throws NoSuchElementException
-     *             if input has been exhausted
-     */
-    public String next(String pattern) {
-        return next(Pattern.compile(pattern));
-    }
-
-    //TODO: To implement this feature
-    public BigDecimal nextBigDecimal() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public BigInteger nextBigInteger() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public BigInteger nextBigInteger(int radix) {
-        throw new NotYetImplementedException();
-    }
-
-    /**
-     * Translates the next token in this scanner's input into a boolean value and
-     * returns this value. This method will throw InputMismatchException if the
-     * next token can not be interpreted as a boolean value with a case
-     * insensitive pattern created from the string "true|false". If this match
-     * succeeds, the scanner advances past the input that matched.
-     * 
-     * @return the boolean value scanned from the input
-     * @throws IllegalStateException
-     *             if this scanner has been closed
-     * @throws NoSuchElementException
-     *             if input has been exhausted
-     * @throws InputMismatchException
-     *             if the next token can not be translated into a valid boolean
-     *             value
-     */
-    public boolean nextBoolean() {
-        return Boolean.parseBoolean(next(BOOLEAN_PATTERN));
-    }
-    
-    //TODO: To implement this feature
-    public byte nextByte() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public byte nextByte(int radix) {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public double nextDouble() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public float nextFloat() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public int nextInt() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public int nextInt(int radix) {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public String nextLine() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public long nextLong() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public long nextLong(int radix) {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public short nextShort() {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public short nextShort(int radix) {
-        throw new NotYetImplementedException();
-    }
-
-    /**
-     * return the radix of this scanner.
-     * 
-     * @return
-     *            the radix of this scanner
-     */
-    public int radix() {
-        return radix;
-    }
-
-    //TODO: To implement this feature
-    public Scanner skip(Pattern pattern) {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public Scanner skip(String pattern) {
-        throw new NotYetImplementedException();
-    }
-
-    //TODO: To implement this feature
-    public String toString() {
-        throw new NotYetImplementedException();
-    }
-
-    /**
-     * Set the delimiting pattern of this scanner
-     * 
-     * @param pattern
-     *            the delimiting pattern to use
-     * @return this scanner
-     */
-    public Scanner useDelimiter(Pattern pattern) {
-        delimiter = pattern;
-        return this;
-    }
-
-    /**
-     * Set the delimiting pattern of this scanner with a pattern compiled from
-     * the supplied string value
-     * 
-     * @param pattern
-     *            a string from which a <code>Pattern</code> can be compiled
-     * @return this scanner
-     */
-    public Scanner useDelimiter(String pattern) {
-        return useDelimiter(Pattern.compile(pattern));
-    }
-
-    /**
-     * 
-     * set the locale of this scanner to a specified locale. 
-     *
-     * @param locale
-     *              the specified locale to use
-     * @return
-     *              this scanner
-     */
-    public Scanner useLocale(Locale locale) {
-        if (null == locale)
-            throw new NullPointerException();
-        this.locale = locale;
-        return this;
-    }
-
-    /**
-     * 
-     * set the radix of this scanner to a specified radix.
-     * 
-     * @param radix
-     *             the specified radix to use
-     * @return
-     *             this scanner
-     */
-    public Scanner useRadix(int radix) {
-        if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX) {
-            throw new IllegalArgumentException(org.apache.harmony.luni.util.Msg
-                    .getString("KA008", radix));
-        }
-        this.radix = radix;
-        return this;
-    }
-
-    /**
-     * 
-     * The operation of remove is not supported by this implementation of
-     * Iterator.
-     * 
-     * @return UnsupportedOperationException 
-     *            if this method is invoked
-     */
-    public void remove() {
-        throw new UnsupportedOperationException();
-    }
-
-    /*
-     * Initial some components.
-     */
-    private void initialization() {
-        buffer = CharBuffer.allocate(DEFAULT_TRUNK_SIZE);
-        buffer.limit(0);
-        matcher = delimiter.matcher(buffer);
-    }
-    
-    /*
-     * Check the scanner's state, if it is closed, IllegalStateException will be
-     * thrown.
-     */
-    private void checkClosed() {
-        if (closed) {
-            throw new IllegalStateException();
-        }
-    }
-
-    /*
-     * Check input resource of this scanner, if it has been exhausted, return
-     * true.
-     */
-    private boolean isInputExhausted() {
-        if (findStartIndex == bufferLength) {
-            if (readMore()) {
-                resetMatcher();
-            } else {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    /*
-     * Change the matcher's string after reading input
-     */
-    private void resetMatcher() {
-        if (null == matcher) {
-            matcher = delimiter.matcher(buffer);
-        } else {
-            matcher.reset(buffer);
-        }
-        matcher.region(findStartIndex, bufferLength);
-    }
-
-    /*
-     * save the matcher's last find position
-     */
-    private void saveCurrentStatus() {
-        preStartIndex = findStartIndex;
-    }
-
-    /*
-     * Change the matcher's status to  last find position
-     */
-    private void recoverPreviousStatus() {
-        findStartIndex = preStartIndex;
-    }
-
-    /*
-     * Find the prefixed delimiter and posefixed delimiter in the input resource
-     * and set the start index and end index of Matcher region. If postfixed
-     * delimiter does not exist, the end index is set to be end of input.
-     */
-    private boolean setTokenRegion() {
-        // The position where token begins
-        int tokenStartIndex = 0;
-        // The position where token ends
-        int tokenEndIndex = 0;
-        // Use delimiter pattern
-        matcher.usePattern(delimiter);
-        matcher.region(findStartIndex, bufferLength);
-
-        tokenStartIndex = findPreDelimiter();
-        if (setHeadTokenRegion(tokenStartIndex)) {
-            return true;
-        }
-        tokenEndIndex = findPostDelimiter();
-        // If the second delimiter is not found
-        if (-1 == tokenEndIndex) {
-            // Just first Delimiter Exists
-            if (findStartIndex == bufferLength) {
-                return false;
-            }
-            tokenEndIndex = bufferLength;
-            findStartIndex = bufferLength;
-        }
-
-        matcher.region(tokenStartIndex, tokenEndIndex);
-        return true;
-    }
-
-    /*
-     * Find prefixed delimiter
-     */
-    private int findPreDelimiter() {
-        int tokenStartIndex;
-        boolean findComplete = false;
-        while (!findComplete) {
-            if (findComplete = matcher.find()) {
-                // If just delimiter remains
-                if (matcher.start() == findStartIndex
-                        && matcher.end() == bufferLength) {
-                    // If more input resource exists
-                    if (readMore()) {
-                        resetMatcher();
-                        findComplete = false;
-                    }
-                }
-            } else {
-                if (readMore()) {
-                    resetMatcher();
-                } else {
-                    return -1;
-                }
-            }
-        }
-        tokenStartIndex = matcher.end();
-        findStartIndex = matcher.end();
-        return tokenStartIndex;
-    }
-
-    /*
-     * Handle some special cases
-     */
-    private boolean setHeadTokenRegion(int findIndex) {
-        int tokenStartIndex;
-        int tokenEndIndex;
-        boolean setSuccess = false;
-        // If no delimiter exists, but something exites in this scanner
-        if (-1 == findIndex && preStartIndex != bufferLength) {
-            tokenStartIndex = preStartIndex;
-            tokenEndIndex = bufferLength;
-            findStartIndex = bufferLength;
-            matcher.region(tokenStartIndex, tokenEndIndex);
-            setSuccess = true;
-        }
-        // If the first delimiter of scanner is not at the find start position
-        if (-1 != findIndex && preStartIndex != matcher.start()) {
-            tokenStartIndex = preStartIndex;
-            tokenEndIndex = matcher.start();
-            findStartIndex = matcher.start();
-            // set match region and return
-            matcher.region(tokenStartIndex, tokenEndIndex);
-            setSuccess = true;
-        }
-        return setSuccess;
-    }
-
-    /*
-     * Find postfixed delimiter
-     */
-    private int findPostDelimiter() {
-        int tokenEndIndex = 0;
-        boolean findComplete = false;
-        while (!findComplete) {
-            if (findComplete = matcher.find()) {
-                if (matcher.start() == findStartIndex
-                        && matcher.start() == matcher.end()) {
-                    findComplete = false;
-                }
-            } else {
-                if (readMore()) {
-                    resetMatcher();
-                } else {
-                    return -1;
-                }
-            }
-        }
-        tokenEndIndex = matcher.start();
-        findStartIndex = matcher.start();
-        return tokenEndIndex;
-    }
-
-    /*
-     * Read more data from underlying Readable. Return false if nothing is
-     * available or I/O operation fails.
-     */
-    private boolean readMore() {
-        int oldPosition = buffer.position();
-        int oldLimit = buffer.limit();
-        // Increase capacity if empty space is not enough
-        if (buffer.limit() >= buffer.capacity()) {
-            expandBuffer();
-        }
-
-        // Read input resource
-        int readCount = 0;
-        try {
-            buffer.limit(buffer.capacity());
-            buffer.position(oldLimit);
-            while ((readCount = input.read(buffer)) == 0) {
-                // nothing to do here
-            }
-        } catch (IOException e) {
-            readCount = (buffer.position() - oldLimit);
-            lastIOException = e;
-        }
-
-        // The return value of readable.read() method can be used to record the
-        // actual characters read. Consider the scenario: readable puts 4 chars into
-        // buffer and then an IOException is thrown out. In this case, buffer is
-        // actually grown, but readable.read() will never return.
-
-        buffer.flip();
-        buffer.position(oldPosition);
-        if (-1 != readCount)
-            bufferLength = readCount + bufferLength;
-        return readCount != -1;
-    }
-
-    // Expand the size of internal buffer.
-    private void expandBuffer() {
-        int oldPosition = buffer.position();
-        int oldCapacity = buffer.capacity();
-        int oldLimit = buffer.limit();
-        int newCapacity = oldCapacity * DIPLOID;
-        char[] newBuffer = new char[newCapacity];
-        if (buffer != null) {
-            System.arraycopy(buffer.array(), 0, newBuffer, 0, oldLimit);
-        }
-        buffer = CharBuffer.wrap(newBuffer, 0, newCapacity);
-        buffer.position(oldPosition);
-        buffer.limit(oldLimit);
-    }
-}
+/* Copyright 2006 The Apache Software Foundation or its licensors, as applicable
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package java.util;
+
+import java.io.Closeable;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.StringReader;
+import java.io.UnsupportedEncodingException;
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.nio.CharBuffer;
+import java.nio.channels.Channels;
+import java.nio.channels.ReadableByteChannel;
+import java.nio.charset.Charset;
+import java.text.DecimalFormat;
+import java.text.NumberFormat;
+import java.util.regex.MatchResult;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.apache.harmony.luni.util.NotYetImplementedException;
+
+/**
+ * A parser that parses a text string to primitive types with the help of
+ * regular expression. It supports localized number and various radixes.
+ * 
+ * The input is broken into tokens by the delimiter pattern, which is whitespace
+ * by default. The primitive types can be got via corresponding next methods. If
+ * the token is not in valid format, an InputMissmatchException is thrown.
+ * 
+ * For example: Scanner s = new Scanner("1A true");
+ * System.out.println(s.nextInt(16)); System.out.println(s.nextBoolean()); The
+ * result: 26 true
+ * 
+ * A scanner can find or skip specific pattern with no regard to the delimiter.
+ * All these methods and the various next and hasNext methods may block.
+ * 
+ * Scanner is not thread-safe without external synchronization
+ */
+public final class Scanner implements Iterator<String> {
+
+    //  Default delimiting pattern
+    private static final Pattern DEFAULT_DELIMITER = Pattern
+            .compile("\\p{javaWhitespace}+"); //$NON-NLS-1$
+    
+    //The boolean's pattern
+    private static final Pattern BOOLEAN_PATTERN = Pattern.compile(
+            "true|false", Pattern.CASE_INSENSITIVE); //$NON-NLS-1$
+    
+    // The pattern matching anything
+    private static final Pattern ANY_PATTERN = Pattern.compile("(?s).*");
+
+    private static final int DIPLOID = 2;
+
+    // Default radix
+    private static final int DEFAULT_RADIX = 10;
+
+    private static final int DEFAULT_TRUNK_SIZE = 1024;
+
+    // The input source of scanner
+    private Readable input;
+
+    private CharBuffer buffer;
+
+    private Pattern delimiter = DEFAULT_DELIMITER;
+
+    private Matcher matcher;
+
+    private int radix = DEFAULT_RADIX;
+
+    private Locale locale = Locale.getDefault();
+
+    // The position where find begins
+    private int findStartIndex = 0;
+
+    // The last find start position
+    private int preStartIndex = findStartIndex;
+
+    // The length of the buffer
+    private int bufferLength = 0;
+
+    // Used by find and nextXXX operation
+    private boolean closed = false;
+
+    private IOException lastIOException;
+    
+    private boolean matchSuccessful = false;
+
+    /**
+     * Constructs a scanner that uses File as its input. The default charset is
+     * applied when reading the file.
+     * 
+     * @param src
+     *            the file to be scanned
+     * @throws FileNotFoundException
+     *             if the specified file is not found
+     */
+    public Scanner(File src) throws FileNotFoundException {
+        this(src, Charset.defaultCharset().name());
+    }
+
+    /**
+     * Constructs a scanner that uses File as its input. The specified charset
+     * is applied when reading the file.
+     * 
+     * @param src
+     *            the file to be scanned
+     * @param charsetName
+     *            the name of the encoding type of the file
+     * @throws FileNotFoundException
+     *             if the specified file is not found
+     * @throws IllegalArgumentException
+     *            if the specified coding does not exist
+     */
+    public Scanner(File src, String charsetName) throws FileNotFoundException {
+        if (null == src) {
+            throw new NullPointerException(org.apache.harmony.luni.util.Msg
+                    .getString("KA00a"));
+        }
+        FileInputStream fis = new FileInputStream(src);
+        if (null == charsetName) {
+            throw new IllegalArgumentException(org.apache.harmony.luni.util.Msg
+                    .getString("KA009"));
+        }
+        try {
+            input = new InputStreamReader(fis, charsetName);
+        } catch (UnsupportedEncodingException e) {
+            try {
+                fis.close();
+            } catch (IOException ioException) {
+                // ignore
+            }
+            throw new IllegalArgumentException(e.getMessage());
+        }
+        initialization();
+    }
+
+    /**
+     * Constructs a scanner that uses String as its input.
+     * 
+     * @param src
+     *            the string to be scanned
+     */
+    public Scanner(String src) {
+        input = new StringReader(src);
+        initialization();
+    }
+
+    /**
+     * Constructs a scanner that uses InputStream as its input. The default
+     * charset is applied when decoding the input.
+     * 
+     * @param src
+     *            the input stream to be scanned
+     */
+    public Scanner(InputStream src) {
+        this(src, Charset.defaultCharset().name());
+    }
+
+    /**
+     * Constructs a scanner that uses InputStream as its input. The specified
+     * charset is applied when decoding the input.
+     * 
+     * @param src
+     *            the input stream to be scanned
+     * @param charsetName
+     *            the encoding type of the input stream
+     * @throws IllegalArgumentException
+     *            if the specified character set is not found
+     */
+    public Scanner(InputStream src, String charsetName) {
+        if (null == src) {
+            throw new NullPointerException(org.apache.harmony.luni.util.Msg
+                    .getString("KA00b"));
+        }
+        try {
+            input = new InputStreamReader(src, charsetName);
+        } catch (UnsupportedEncodingException e) {
+            throw new IllegalArgumentException(e.getMessage());
+        }
+        initialization();
+    }
+
+    /**
+     * Constructs a scanner that uses Readable as its input.
+     * 
+     * @param src
+     *            the Readable to be scanned
+     */
+    public Scanner(Readable src) {
+        if (null == src) {
+            throw new NullPointerException();
+        }
+        input = src;
+        initialization();
+    }
+
+    /**
+     * Constructs a scanner that uses ReadableByteChannel as its input. The
+     * default charset is applied when decoding the input.
+     * 
+     * @param src
+     *            the ReadableByteChannel to be scanned
+     */
+    public Scanner(ReadableByteChannel src) {
+        this(src, Charset.defaultCharset().name());
+    }
+
+    /**
+     * Constructs a scanner that uses ReadableByteChannel as its input. The
+     * specified charset is applied when decoding the input.
+     * 
+     * @param src
+     *            the ReadableByteChannel to be scanned
+     * @param charsetName
+     *            the encoding type of the content in the ReadableByteChannel
+     * @throws IllegalArgumentException
+     *            if the specified character set is not found           
+     */
+    public Scanner(ReadableByteChannel src, String charsetName) {
+        if (null == src) {
+            throw new NullPointerException(org.apache.harmony.luni.util.Msg
+                    .getString("KA00d"));
+        }
+        if (null == charsetName) {
+            throw new IllegalArgumentException(org.apache.harmony.luni.util.Msg
+                    .getString("KA009"));
+        }
+        try {
+            input = new InputStreamReader(Channels.newInputStream(src),
+                    charsetName);
+        } catch (UnsupportedEncodingException e) {
+            throw new IllegalArgumentException(e.getMessage());
+        }
+        initialization();
+    }
+
+    /**
+     * Closes the underlying input if the input implements Closeable. If the
+     * scanner has been closed, this method will take no effect. The scanning
+     * operation after calling this method will throw IllegalStateException
+     * 
+     */
+    public void close() {
+        if (closed == true) {
+            return;
+        }
+        if (input instanceof Closeable) {
+            try {
+                ((Closeable) input).close();
+            } catch (IOException e) {
+                lastIOException = e;
+            }
+        }
+        closed = true;
+    }
+
+    /**
+     * Returns the <code>Pattern</code> in use by this scanner.
+     * 
+     * @return the <code>Pattern</code> presently in use by this scanner
+     */
+    public Pattern delimiter() {
+        return delimiter;
+    }
+
+    //TODO: To implement this feature
+    public String findInLine(Pattern pattern) {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public String findInLine(String pattern) {
+        throw new NotYetImplementedException();
+    }
+
+    /**
+     * @param pattern
+     * @param horizon
+     * @return
+     * @throws IllegalStateException
+     * @throws IllegalArgumentException
+     */
+    public String findWithinHorizon(Pattern pattern, int horizon) {
+        checkClosed();
+        if (null == pattern) {
+            throw new NullPointerException();
+        }
+        if (horizon < 0) {
+            throw new IllegalArgumentException(org.apache.harmony.luni.util.Msg
+                    .getString("KA00e")); //$NON-NLS-1$
+        }
+        matcher.usePattern(pattern);
+
+        boolean isInputExhausted = false;
+        String result = null;
+        int findEndIndex = 0;
+        int horizonEndIndex = 0;
+        if (horizon == 0) {
+            horizonEndIndex = Integer.MAX_VALUE;
+        } else {
+            horizonEndIndex = findStartIndex + horizon;
+        }
+        while (true) {
+            findEndIndex = bufferLength;
+
+            // If horizon > 0, then search up to
+            // min( bufferLength, findStartIndex + horizon).
+            // Otherwise search until readable is exhausted.
+            findEndIndex = Math.min(horizonEndIndex, bufferLength);
+            // If horizon == 0, consider horizon as always outside buffer.
+            boolean isHorizonInBuffer = (horizonEndIndex <= bufferLength);
+            // First, try to find pattern within buffer. If pattern can not be
+            // found in buffer, then expand the buffer and try again,
+            // util horizonEndIndex is exceeded or no more input left.
+            matcher.region(findStartIndex, findEndIndex);
+            if (matcher.find()) {
+                if (isHorizonInBuffer || isInputExhausted) {
+                    result = matcher.group();
+                    break;
+                }
+            } else {
+                // Pattern is not found in buffer while horizonEndIndex is
+                // within buffer, or input is exhausted. Under this situation,
+                // it can be judged that find fails.
+                if (isHorizonInBuffer || isInputExhausted) {
+                    break;
+                }
+            }
+
+            // Expand buffer and reset matcher if needed.
+            if (readMore()) {
+                matcher.reset(buffer);
+            } else {
+                isInputExhausted = true;
+            }
+        }
+        if (null != result) {
+            findStartIndex = matcher.end();
+            matchSuccessful = true;
+        } else {
+            matchSuccessful = false;
+        }
+        return result;
+    }
+
+    //TODO: To implement this feature
+    public String findWithinHorizon(String pattern, int horizon) {
+        throw new NotYetImplementedException();
+    }
+
+    /**
+     * Returns true if this scanner has next token. This method may be blocked
+     * when it is waiting for input to scan. This scanner does not advance past
+     * the input.
+     * 
+     * @return true 
+     *             iff this scanner has next token
+     * @throws IllegalStateException
+     *             if the scanner has been closed
+     */
+    public boolean hasNext() {
+        return hasNext(ANY_PATTERN);
+    }
+
+    /**
+     * Returns true if this scanner's next token matches the specified pattern.
+     * This method may be blocked when it is waiting for input to scan. This
+     * scanner does not advance past the input that matched the pattern.
+     * 
+     * @param pattern
+     *            the specified pattern to scan
+     * @return 
+     *            true iff this scanner's next token matches the specified pattern
+     * @throws IllegalStateException
+     *            if the scanner has been closed
+     */
+    public boolean hasNext(Pattern pattern) {
+        checkClosed();
+        if (isInputExhausted()) {
+            return false;
+        }
+        saveCurrentStatus();
+        //if the next token exists, set the match region, otherwise return false
+        if (!setTokenRegion()) {
+            recoverPreviousStatus();
+            return false;
+        }
+        matcher.usePattern(pattern);
+        boolean hasNext = false;
+        //check whether next token matches the specified pattern
+        if (matcher.matches()) {
+            hasNext = true;
+        }
+        recoverPreviousStatus();
+        return hasNext;
+    }
+
+
+    /**
+     * Returns true if this scanner's next token matches the pattern constructed
+     * from the specified string. This method may be blocked when it is waiting
+     * for input to scan. This scanner does not advance past the input that
+     * matched the pattern.
+     * 
+     * The invocation of this method in the form hasNext(pattern) behaves in the
+     * same way as the invocaiton of hasNext(Pattern.compile(pattern)).
+     * 
+     * @param pattern
+     *            the string specifying the pattern to scan for
+     * @return true 
+     *            iff this scanner's next token matches the specified pattern
+     * @throws IllegalStateException
+     *             if the scanner has been closed
+     */
+    public boolean hasNext(String pattern) {
+        return hasNext(Pattern.compile(pattern));
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextBigDecimal() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextBigInteger() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextBigInteger(int radix) {
+        throw new NotYetImplementedException();
+    }
+
+    /**
+     * Returns true if this scanner's next token can be translated into a valid
+     * boolean value. The scanner does not advance past the input that matched.
+     * 
+     * @return true 
+     *             iff the next token in this scanner's input can be translated
+     *         into a valid boolean value
+     * @throws IllegalStateException
+     *             if the scanner has been closed
+     */
+    public boolean hasNextBoolean() {
+        return hasNext(BOOLEAN_PATTERN);
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextByte() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextByte(int radix) {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextDouble() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextFloat() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextInt() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextInt(int radix) {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextLine() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextLong() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextLong(int radix) {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextShort() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public boolean hasNextShort(int radix) {
+        throw new NotYetImplementedException();
+    }
+
+    /**
+     * returns the last IOException thrown when reading the underlying input. If
+     * no exception is thrown, return null.
+     * 
+     * @return the last IOException thrown
+     */
+    public IOException ioException() {
+        return lastIOException;
+    }
+
+    /**
+     * return the locale of this scanner.
+     * 
+     * @return 
+     *             the locale of this scanner
+     */
+    public Locale locale() {
+        return locale;
+    }
+
+    /**
+     * Returns the match result of this scanner's last match operation.This
+     * method throws IllegalStateException if no match operation has been
+     * performed, or if the last match was unsuccessful.
+     * 
+     * The various nextXXX methods of Scanner provide a match result if they do
+     * not complete with throwing an exception. For example, after an invocation
+     * of the nextBoolean() method which returned a boolean value, this method
+     * returns a match result for the search of the Boolean regular expression
+     * defined above. In the same way,the findInLine(java.lang.String),
+     * findWithinHorizon(java.lang.String, int), and
+     * skip(java.util.regex.Pattern) methods will provide a match result if they
+     * are successful.
+     * 
+     * @return the match result of the last match operation
+     * @throws IllegalStateException
+     *             if the match result is available
+     */
+    public MatchResult match() {
+        if (!matchSuccessful) {
+            throw new IllegalStateException();
+        }
+        return matcher.toMatchResult();
+    }
+
+    /**
+     * Finds and Returns the next complete token which is prefixed and postfixed
+     * by input that matches the delimiter pattern. This method may be blocked
+     * when it is waiting for input to scan, even if a previous invocation of
+     * hasNext() returned true. If this match successes, the scanner advances
+     * past the next complete token.
+     * 
+     * @return 
+     *             the next complete token
+     * @throws IllegalStateException
+     *             if this scanner has been closed
+     * @throws NoSuchElementException
+     *             if input has been exhausted
+     */
+    public String next() {
+        return next(ANY_PATTERN);
+    }
+
+    /**
+     * Returns the next token which is prefixed and postfixed by input that
+     * matches the delimiter pattern if this token matches the specified
+     * pattern. This method may be blocked when it is waiting for input to scan,
+     * even if a previous invocation of hasNext(Pattern) returned true. If this
+     * match successes, the scanner advances past the next token that matched
+     * the pattern.
+     * 
+     * @param pattern
+     *            the specified pattern to scan
+     * @return 
+     *             the next token
+     * @throws IllegalStateException
+     *             if this scanner has been closed
+     * @throws NoSuchElementException
+     *             if input has been exhausted
+     */
+    public String next(Pattern pattern) {
+        checkClosed();
+        if (null == pattern) {
+            throw new NullPointerException();
+        }
+        matchSuccessful = false;
+        if (isInputExhausted()) {
+            throw new NoSuchElementException();
+        }
+        saveCurrentStatus();
+        if (!setTokenRegion()) {
+            recoverPreviousStatus();
+            // if setting match region fails
+            throw new NoSuchElementException();
+        }
+        matcher.usePattern(pattern);
+        if (matchSuccessful = matcher.matches()) {
+            return matcher.group(0);
+        } else {
+            recoverPreviousStatus();
+            throw new InputMismatchException();
+        }
+    }
+
+    /**
+     * Returns the next token which is prefixed and postfixed by input that
+     * matches the delimiter pattern if this token matches the pattern
+     * constructed from the sepcified string. This method may be blocked when it
+     * is waiting for input to scan. If this match successes, the scanner
+     * advances past the next token that matched the pattern.
+     * 
+     * The invocation of this method in the form next(pattern) behaves in the
+     * same way as the invocaiton of next(Pattern.compile(pattern)).
+     * 
+     * @param pattern
+     *            the string specifying the pattern to scan for
+     * @return 
+     *             the next token
+     * @throws IllegalStateException
+     *             if this scanner has been closed
+     * @throws NoSuchElementException
+     *             if input has been exhausted
+     */
+    public String next(String pattern) {
+        return next(Pattern.compile(pattern));
+    }
+
+    //TODO: To implement this feature
+    public BigDecimal nextBigDecimal() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public BigInteger nextBigInteger() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public BigInteger nextBigInteger(int radix) {
+        throw new NotYetImplementedException();
+    }
+
+    /**
+     * Translates the next token in this scanner's input into a boolean value and
+     * returns this value. This method will throw InputMismatchException if the
+     * next token can not be interpreted as a boolean value with a case
+     * insensitive pattern created from the string "true|false". If this match
+     * succeeds, the scanner advances past the input that matched.
+     * 
+     * @return the boolean value scanned from the input
+     * @throws IllegalStateException
+     *             if this scanner has been closed
+     * @throws NoSuchElementException
+     *             if input has been exhausted
+     * @throws InputMismatchException
+     *             if the next token can not be translated into a valid boolean
+     *             value
+     */
+    public boolean nextBoolean() {
+        return Boolean.parseBoolean(next(BOOLEAN_PATTERN));
+    }
+    
+    //TODO: To implement this feature
+    public byte nextByte() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public byte nextByte(int radix) {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public double nextDouble() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public float nextFloat() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public int nextInt() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public int nextInt(int radix) {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public String nextLine() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public long nextLong() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public long nextLong(int radix) {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public short nextShort() {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public short nextShort(int radix) {
+        throw new NotYetImplementedException();
+    }
+
+    /**
+     * return the radix of this scanner.
+     * 
+     * @return
+     *            the radix of this scanner
+     */
+    public int radix() {
+        return radix;
+    }
+
+    //TODO: To implement this feature
+    public Scanner skip(Pattern pattern) {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public Scanner skip(String pattern) {
+        throw new NotYetImplementedException();
+    }
+
+    //TODO: To implement this feature
+    public String toString() {
+        throw new NotYetImplementedException();
+    }
+
+    /**
+     * Set the delimiting pattern of this scanner
+     * 
+     * @param pattern
+     *            the delimiting pattern to use
+     * @return this scanner
+     */
+    public Scanner useDelimiter(Pattern pattern) {
+        delimiter = pattern;
+        return this;
+    }
+
+    /**
+     * Set the delimiting pattern of this scanner with a pattern compiled from
+     * the supplied string value
+     * 
+     * @param pattern
+     *            a string from which a <code>Pattern</code> can be compiled
+     * @return this scanner
+     */
+    public Scanner useDelimiter(String pattern) {
+        return useDelimiter(Pattern.compile(pattern));
+    }
+
+    /**
+     * 
+     * set the locale of this scanner to a specified locale. 
+     *
+     * @param locale
+     *              the specified locale to use
+     * @return
+     *              this scanner
+     */
+    public Scanner useLocale(Locale locale) {
+        if (null == locale)
+            throw new NullPointerException();
+        this.locale = locale;
+        return this;
+    }
+
+    /**
+     * 
+     * set the radix of this scanner to a specified radix.
+     * 
+     * @param radix
+     *             the specified radix to use
+     * @return
+     *             this scanner
+     */
+    public Scanner useRadix(int radix) {
+        if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX) {
+            throw new IllegalArgumentException(org.apache.harmony.luni.util.Msg
+                    .getString("KA008", radix));
+        }
+        this.radix = radix;
+        return this;
+    }
+
+    /**
+     * 
+     * The operation of remove is not supported by this implementation of
+     * Iterator.
+     * 
+     * @return UnsupportedOperationException 
+     *            if this method is invoked
+     */
+    public void remove() {
+        throw new UnsupportedOperationException();
+    }
+
+    /*
+     * Initial some components.
+     */
+    private void initialization() {
+        buffer = CharBuffer.allocate(DEFAULT_TRUNK_SIZE);
+        buffer.limit(0);
+        matcher = delimiter.matcher(buffer);
+    }
+    
+    /*
+     * Check the scanner's state, if it is closed, IllegalStateException will be
+     * thrown.
+     */
+    private void checkClosed() {
+        if (closed) {
+            throw new IllegalStateException();
+        }
+    }
+
+    /*
+     * Check input resource of this scanner, if it has been exhausted, return
+     * true.
+     */
+    private boolean isInputExhausted() {
+        if (findStartIndex == bufferLength) {
+            if (readMore()) {
+                resetMatcher();
+            } else {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /*
+     * Change the matcher's string after reading input
+     */
+    private void resetMatcher() {
+        if (null == matcher) {
+            matcher = delimiter.matcher(buffer);
+        } else {
+            matcher.reset(buffer);
+        }
+        matcher.region(findStartIndex, bufferLength);
+    }
+
+    /*
+     * save the matcher's last find position
+     */
+    private void saveCurrentStatus() {
+        preStartIndex = findStartIndex;
+    }
+
+    /*
+     * Change the matcher's status to  last find position
+     */
+    private void recoverPreviousStatus() {
+        findStartIndex = preStartIndex;
+    }
+
+    /*
+     * Find the prefixed delimiter and posefixed delimiter in the input resource
+     * and set the start index and end index of Matcher region. If postfixed
+     * delimiter does not exist, the end index is set to be end of input.
+     */
+    private boolean setTokenRegion() {
+        // The position where token begins
+        int tokenStartIndex = 0;
+        // The position where token ends
+        int tokenEndIndex = 0;
+        // Use delimiter pattern
+        matcher.usePattern(delimiter);
+        matcher.region(findStartIndex, bufferLength);
+
+        tokenStartIndex = findPreDelimiter();
+        if (setHeadTokenRegion(tokenStartIndex)) {
+            return true;
+        }
+        tokenEndIndex = findPostDelimiter();
+        // If the second delimiter is not found
+        if (-1 == tokenEndIndex) {
+            // Just first Delimiter Exists
+            if (findStartIndex == bufferLength) {
+                return false;
+            }
+            tokenEndIndex = bufferLength;
+            findStartIndex = bufferLength;
+        }
+
+        matcher.region(tokenStartIndex, tokenEndIndex);
+        return true;
+    }
+
+    /*
+     * Find prefixed delimiter
+     */
+    private int findPreDelimiter() {
+        int tokenStartIndex;
+        boolean findComplete = false;
+        while (!findComplete) {
+            if (findComplete = matcher.find()) {
+                // If just delimiter remains
+                if (matcher.start() == findStartIndex
+                        && matcher.end() == bufferLength) {
+                    // If more input resource exists
+                    if (readMore()) {
+                        resetMatcher();
+                        findComplete = false;
+                    }
+                }
+            } else {
+                if (readMore()) {
+                    resetMatcher();
+                } else {
+                    return -1;
+                }
+            }
+        }
+        tokenStartIndex = matcher.end();
+        findStartIndex = matcher.end();
+        return tokenStartIndex;
+    }
+
+    /*
+     * Handle some special cases
+     */
+    private boolean setHeadTokenRegion(int findIndex) {
+        int tokenStartIndex;
+        int tokenEndIndex;
+        boolean setSuccess = false;
+        // If no delimiter exists, but something exites in this scanner
+        if (-1 == findIndex && preStartIndex != bufferLength) {
+            tokenStartIndex = preStartIndex;
+            tokenEndIndex = bufferLength;
+            findStartIndex = bufferLength;
+            matcher.region(tokenStartIndex, tokenEndIndex);
+            setSuccess = true;
+        }
+        // If the first delimiter of scanner is not at the find start position
+        if (-1 != findIndex && preStartIndex != matcher.start()) {
+            tokenStartIndex = preStartIndex;
+            tokenEndIndex = matcher.start();
+            findStartIndex = matcher.start();
+            // set match region and return
+            matcher.region(tokenStartIndex, tokenEndIndex);
+            setSuccess = true;
+        }
+        return setSuccess;
+    }
+
+    /*
+     * Find postfixed delimiter
+     */
+    private int findPostDelimiter() {
+        int tokenEndIndex = 0;
+        boolean findComplete = false;
+        while (!findComplete) {
+            if (findComplete = matcher.find()) {
+                if (matcher.start() == findStartIndex
+                        && matcher.start() == matcher.end()) {
+                    findComplete = false;
+                }
+            } else {
+                if (readMore()) {
+                    resetMatcher();
+                } else {
+                    return -1;
+                }
+            }
+        }
+        tokenEndIndex = matcher.start();
+        findStartIndex = matcher.start();
+        return tokenEndIndex;
+    }
+
+    /*
+     * Read more data from underlying Readable. Return false if nothing is
+     * available or I/O operation fails.
+     */
+    private boolean readMore() {
+        int oldPosition = buffer.position();
+        int oldLimit = buffer.limit();
+        // Increase capacity if empty space is not enough
+        if (buffer.limit() >= buffer.capacity()) {
+            expandBuffer();
+        }
+
+        // Read input resource
+        int readCount = 0;
+        try {
+            buffer.limit(buffer.capacity());
+            buffer.position(oldLimit);
+            while ((readCount = input.read(buffer)) == 0) {
+                // nothing to do here
+            }
+        } catch (IOException e) {
+            readCount = (buffer.position() - oldLimit);
+            lastIOException = e;
+        }
+
+        // The return value of readable.read() method can be used to record the
+        // actual characters read. Consider the scenario: readable puts 4 chars into
+        // buffer and then an IOException is thrown out. In this case, buffer is
+        // actually grown, but readable.read() will never return.
+
+        buffer.flip();
+        buffer.position(oldPosition);
+        if (-1 != readCount)
+            bufferLength = readCount + bufferLength;
+        return readCount != -1;
+    }
+
+    // Expand the size of internal buffer.
+    private void expandBuffer() {
+        int oldPosition = buffer.position();
+        int oldCapacity = buffer.capacity();
+        int oldLimit = buffer.limit();
+        int newCapacity = oldCapacity * DIPLOID;
+        char[] newBuffer = new char[newCapacity];
+        if (buffer != null) {
+            System.arraycopy(buffer.array(), 0, newBuffer, 0, oldLimit);
+        }
+        buffer = CharBuffer.wrap(newBuffer, 0, newCapacity);
+        buffer.position(oldPosition);
+        buffer.limit(oldLimit);
+    }
+}