/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/**
* The string tokenizer class allows an application to break a
* string into tokens. The tokenization method is much simpler than
* the one used by the <code>StreamTokenizer</code> class. The
* <code>StringTokenizer</code> methods do not distinguish among
* identifiers, numbers, and quoted strings, nor do they recognize
* and skip comments.
* <p>
* The set of delimiters (the characters that separate tokens) may
* be specified either at creation time or on a per-token basis.
* <p>
* An instance of <code>StringTokenizer</code> behaves in one of two
* ways, depending on whether it was created with the
* <code>returnDelims</code> flag having the value <code>true</code>
* or <code>false</code>:
* <ul>
* <li>If the flag is <code>false</code>, delimiter characters serve to
* separate tokens. A token is a maximal sequence of consecutive
* characters that are not delimiters.
* <li>If the flag is <code>true</code>, delimiter characters are themselves
* considered to be tokens. A token is thus either one delimiter
* character, or a maximal sequence of consecutive characters that are
* not delimiters.
* </ul><p>
* A <tt>StringTokenizer</tt> object internally maintains a current
* position within the string to be tokenized. Some operations advance this
* current position past the characters processed.<p>
* A token is returned by taking a substring of the string that was used to
* create the <tt>StringTokenizer</tt> object.
* <p>
* The following is one example of the use of the tokenizer. The code:
* <blockquote><pre>
* StringTokenizer st = new StringTokenizer("this is a test");
* while (st.hasMoreTokens()) {
* System.out.println(st.nextToken());
* }
* </pre></blockquote>
* <p>
* prints the following output:
* <blockquote><pre>
* this
* is
* a
* test
* </pre></blockquote>
*
* <p>
* <tt>StringTokenizer</tt> is a legacy class that is retained for
* compatibility reasons although its use is discouraged in new code. It is
* recommended that anyone seeking this functionality use the <tt>split</tt>
* method of <tt>String</tt> or the java.util.regex package instead.
* <p>
* The following example illustrates how the <tt>String.split</tt>
* method can be used to break up a string into its basic tokens:
* <blockquote><pre>
* String[] result = "this is a test".split("\\s");
* for (int x=0; x<result.length; x++)
* System.out.println(result[x]);
* </pre></blockquote>
* <p>
* prints the following output:
* <blockquote><pre>
* this
* is
* a
* test
* </pre></blockquote>
*
* @author unascribed
* @see java.io.StreamTokenizer
* @since JDK1.0
*/
public
private int currentPosition;
private int newPosition;
private int maxPosition;
private boolean retDelims;
private boolean delimsChanged;
/**
* maxDelimCodePoint stores the value of the delimiter character with the
* highest value. It is used to optimize the detection of delimiter
* characters.
*
* It is unlikely to provide any optimization benefit in the
* hasSurrogates case because most string characters will be
* smaller than the limit, but we keep it so that the two code
* paths remain similar.
*/
private int maxDelimCodePoint;
/**
* If delimiters include any surrogates (including surrogate
* pairs), hasSurrogates is true and the tokenizer uses the
* different code path. This is because String.indexOf(int)
* doesn't handle unpaired surrogates as a single character.
*/
private boolean hasSurrogates = false;
/**
* When hasSurrogates is true, delimiters are converted to code
* points and isDelimiter(int) is used to determine if the given
* codepoint is a delimiter.
*/
private int[] delimiterCodePoints;
/**
* Set maxDelimCodePoint to the highest char in the delimiter set.
*/
private void setMaxDelimCodePoint() {
if (delimiters == null) {
maxDelimCodePoint = 0;
return;
}
int m = 0;
int c;
int count = 0;
c = delimiters.charAt(i);
c = delimiters.codePointAt(i);
hasSurrogates = true;
}
if (m < c)
m = c;
count++;
}
maxDelimCodePoint = m;
if (hasSurrogates) {
delimiterCodePoints = new int[count];
c = delimiters.codePointAt(j);
delimiterCodePoints[i] = c;
}
}
}
/**
* Constructs a string tokenizer for the specified string. All
* characters in the <code>delim</code> argument are the delimiters
* for separating tokens.
* <p>
* If the <code>returnDelims</code> flag is <code>true</code>, then
* the delimiter characters are also returned as tokens. Each
* delimiter is returned as a string of length one. If the flag is
* <code>false</code>, the delimiter characters are skipped and only
* serve as separators between tokens.
* <p>
* Note that if <tt>delim</tt> is <tt>null</tt>, this constructor does
* not throw an exception. However, trying to invoke other methods on the
* resulting <tt>StringTokenizer</tt> may result in a
* <tt>NullPointerException</tt>.
*
* @param str a string to be parsed.
* @param delim the delimiters.
* @param returnDelims flag indicating whether to return the delimiters
* as tokens.
* @exception NullPointerException if str is <CODE>null</CODE>
*/
currentPosition = 0;
newPosition = -1;
delimsChanged = false;
delimiters = delim;
}
/**
* Constructs a string tokenizer for the specified string. The
* characters in the <code>delim</code> argument are the delimiters
* for separating tokens. Delimiter characters themselves will not
* be treated as tokens.
* <p>
* Note that if <tt>delim</tt> is <tt>null</tt>, this constructor does
* not throw an exception. However, trying to invoke other methods on the
* resulting <tt>StringTokenizer</tt> may result in a
* <tt>NullPointerException</tt>.
*
* @param str a string to be parsed.
* @param delim the delimiters.
* @exception NullPointerException if str is <CODE>null</CODE>
*/
}
/**
* Constructs a string tokenizer for the specified string. The
* tokenizer uses the default delimiter set, which is
* <code>" \t\n\r\f"</code>: the space character,
* the tab character, the newline character, the carriage-return character,
* and the form-feed character. Delimiter characters themselves will
* not be treated as tokens.
*
* @param str a string to be parsed.
* @exception NullPointerException if str is <CODE>null</CODE>
*/
this(str, " \t\n\r\f", false);
}
/**
* Skips delimiters starting from the specified position. If retDelims
* is false, returns the index of the first non-delimiter character at or
* after startPos. If retDelims is true, startPos is returned.
*/
if (delimiters == null)
throw new NullPointerException();
if (!hasSurrogates) {
break;
position++;
} else {
if ((c > maxDelimCodePoint) || !isDelimiter(c)) {
break;
}
}
}
return position;
}
/**
* Skips ahead from startPos and returns the index of the next delimiter
* character encountered, or maxPosition if no such delimiter is found.
*/
while (position < maxPosition) {
if (!hasSurrogates) {
break;
position++;
} else {
if ((c <= maxDelimCodePoint) && isDelimiter(c))
break;
}
}
if (!hasSurrogates) {
position++;
} else {
if ((c <= maxDelimCodePoint) && isDelimiter(c))
}
}
return position;
}
if (delimiterCodePoints[i] == codePoint) {
return true;
}
}
return false;
}
/**
* Tests if there are more tokens available from this tokenizer's string.
* If this method returns <tt>true</tt>, then a subsequent call to
* <tt>nextToken</tt> with no argument will successfully return a token.
*
* @return <code>true</code> if and only if there is at least one token
* in the string after the current position; <code>false</code>
* otherwise.
*/
public boolean hasMoreTokens() {
/*
* Temporarily store this position and use it in the following
* nextToken() method only if the delimiters haven't been changed in
* that nextToken() invocation.
*/
return (newPosition < maxPosition);
}
/**
* Returns the next token from this string tokenizer.
*
* @return the next token from this string tokenizer.
* @exception NoSuchElementException if there are no more tokens in this
* tokenizer's string.
*/
/*
* If next position already computed in hasMoreElements() and
* delimiters have changed between the computation and this invocation,
* then use the computed value.
*/
/* Reset these anyway */
delimsChanged = false;
newPosition = -1;
if (currentPosition >= maxPosition)
throw new NoSuchElementException();
int start = currentPosition;
}
/**
* Returns the next token in this string tokenizer's string. First,
* the set of characters considered to be delimiters by this
* <tt>StringTokenizer</tt> object is changed to be the characters in
* the string <tt>delim</tt>. Then the next token in the string
* after the current position is returned. The current position is
* advanced beyond the recognized token. The new delimiter set
* remains the default after this call.
*
* @param delim the new delimiters.
* @return the next token, after switching to the new delimiter set.
* @exception NoSuchElementException if there are no more tokens in this
* tokenizer's string.
* @exception NullPointerException if delim is <CODE>null</CODE>
*/
delimiters = delim;
/* delimiter string specified, so set the appropriate flag. */
delimsChanged = true;
return nextToken();
}
/**
* Returns the same value as the <code>hasMoreTokens</code>
* method. It exists so that this class can implement the
* <code>Enumeration</code> interface.
*
* @return <code>true</code> if there are more tokens;
* <code>false</code> otherwise.
* @see java.util.Enumeration
* @see java.util.StringTokenizer#hasMoreTokens()
*/
public boolean hasMoreElements() {
return hasMoreTokens();
}
/**
* Returns the same value as the <code>nextToken</code> method,
* except that its declared return value is <code>Object</code> rather than
* <code>String</code>. It exists so that this class can implement the
* <code>Enumeration</code> interface.
*
* @return the next token in the string.
* @exception NoSuchElementException if there are no more tokens in this
* tokenizer's string.
* @see java.util.Enumeration
* @see java.util.StringTokenizer#nextToken()
*/
return nextToken();
}
/**
* Calculates the number of times that this tokenizer's
* <code>nextToken</code> method can be called before it generates an
* exception. The current position is not advanced.
*
* @return the number of tokens remaining in the string using the current
* delimiter set.
* @see java.util.StringTokenizer#nextToken()
*/
public int countTokens() {
int count = 0;
int currpos = currentPosition;
while (currpos < maxPosition) {
if (currpos >= maxPosition)
break;
count++;
}
return count;
}
}