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Diffstat (limited to 'libjava/classpath/java/util/StringTokenizer.java')
-rw-r--r-- | libjava/classpath/java/util/StringTokenizer.java | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/libjava/classpath/java/util/StringTokenizer.java b/libjava/classpath/java/util/StringTokenizer.java new file mode 100644 index 0000000..dcc192c --- /dev/null +++ b/libjava/classpath/java/util/StringTokenizer.java @@ -0,0 +1,268 @@ +/* StringTokenizer -- breaks a String into tokens + Copyright (C) 1998, 1999, 2001, 2002, 2005 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package java.util; + +/** + * This class splits a string into tokens. The caller can set on which + * delimiters the string should be split and if the delimiters should be + * returned. This is much simpler than {@link java.io.StreamTokenizer}. + * + * <p>You may change the delimiter set on the fly by calling + * nextToken(String). But the semantic is quite difficult; it even + * depends on calling <code>hasMoreTokens()</code>. You should call + * <code>hasMoreTokens()</code> before, otherwise the old delimiters + * after the last token are candidates for being returned. + * + * <p>If you want to get the delimiters, you have to use the three argument + * constructor. The delimiters are returned as token consisting of a + * single character. + * + * @author Jochen Hoenicke + * @author Warren Levy (warrenl@cygnus.com) + * @see java.io.StreamTokenizer + * @status updated to 1.4 + */ +public class StringTokenizer implements Enumeration +{ + // WARNING: StringTokenizer is a CORE class in the bootstrap cycle. See the + // comments in vm/reference/java/lang/Runtime for implications of this fact. + + /** + * The position in the str, where we currently are. + */ + private int pos; + + /** + * The string that should be split into tokens. + */ + private final String str; + + /** + * The length of the string. + */ + private final int len; + + /** + * The string containing the delimiter characters. + */ + private String delim; + + /** + * Tells, if we should return the delimiters. + */ + private final boolean retDelims; + + /** + * Creates a new StringTokenizer for the string <code>str</code>, + * that should split on the default delimiter set (space, tab, + * newline, return and formfeed), and which doesn't return the + * delimiters. + * + * @param str The string to split + * @throws NullPointerException if str is null + */ + public StringTokenizer(String str) + { + this(str, " \t\n\r\f", false); + } + + /** + * Create a new StringTokenizer, that splits the given string on + * the given delimiter characters. It doesn't return the delimiter + * characters. + * + * @param str the string to split + * @param delim a string containing all delimiter characters + * @throws NullPointerException if either argument is null + */ + public StringTokenizer(String str, String delim) + { + this(str, delim, false); + } + + /** + * Create a new StringTokenizer, that splits the given string on + * the given delimiter characters. If you set + * <code>returnDelims</code> to <code>true</code>, the delimiter + * characters are returned as tokens of their own. The delimiter + * tokens always consist of a single character. + * + * @param str the string to split + * @param delim a string containing all delimiter characters + * @param returnDelims tells, if you want to get the delimiters + * @throws NullPointerException if str or delim is null + */ + public StringTokenizer(String str, String delim, boolean returnDelims) + { + len = str.length(); + this.str = str; + // The toString() hack causes the NullPointerException. + this.delim = delim.toString(); + this.retDelims = returnDelims; + this.pos = 0; + } + + /** + * Tells if there are more tokens. + * + * @return true if the next call of nextToken() will succeed + */ + public boolean hasMoreTokens() + { + if (! retDelims) + { + while (pos < len && delim.indexOf(str.charAt(pos)) >= 0) + pos++; + } + return pos < len; + } + + /** + * Returns the nextToken, changing the delimiter set to the given + * <code>delim</code>. The change of the delimiter set is + * permanent, ie. the next call of nextToken(), uses the same + * delimiter set. + * + * @param delim a string containing the new delimiter characters + * @return the next token with respect to the new delimiter characters + * @throws NoSuchElementException if there are no more tokens + * @throws NullPointerException if delim is null + */ + public String nextToken(String delim) throws NoSuchElementException + { + this.delim = delim; + return nextToken(); + } + + /** + * Returns the nextToken of the string. + * + * @return the next token with respect to the current delimiter characters + * @throws NoSuchElementException if there are no more tokens + */ + public String nextToken() throws NoSuchElementException + { + if (pos < len && delim.indexOf(str.charAt(pos)) >= 0) + { + if (retDelims) + return str.substring(pos, ++pos); + while (++pos < len && delim.indexOf(str.charAt(pos)) >= 0); + } + if (pos < len) + { + int start = pos; + while (++pos < len && delim.indexOf(str.charAt(pos)) < 0); + + return str.substring(start, pos); + } + throw new NoSuchElementException(); + } + + /** + * This does the same as hasMoreTokens. This is the + * <code>Enumeration</code> interface method. + * + * @return true, if the next call of nextElement() will succeed + * @see #hasMoreTokens() + */ + public boolean hasMoreElements() + { + return hasMoreTokens(); + } + + /** + * This does the same as nextTokens. This is the + * <code>Enumeration</code> interface method. + * + * @return the next token with respect to the current delimiter characters + * @throws NoSuchElementException if there are no more tokens + * @see #nextToken() + */ + public Object nextElement() throws NoSuchElementException + { + return nextToken(); + } + + /** + * This counts the number of remaining tokens in the string, with + * respect to the current delimiter set. + * + * @return the number of times <code>nextTokens()</code> will succeed + * @see #nextToken() + */ + public int countTokens() + { + int count = 0; + int delimiterCount = 0; + boolean tokenFound = false; // Set when a non-delimiter is found + int tmpPos = pos; + + // Note for efficiency, we count up the delimiters rather than check + // retDelims every time we encounter one. That way, we can + // just do the conditional once at the end of the method + while (tmpPos < len) + { + if (delim.indexOf(str.charAt(tmpPos++)) >= 0) + { + if (tokenFound) + { + // Got to the end of a token + count++; + tokenFound = false; + } + delimiterCount++; // Increment for this delimiter + } + else + { + tokenFound = true; + // Get to the end of the token + while (tmpPos < len + && delim.indexOf(str.charAt(tmpPos)) < 0) + ++tmpPos; + } + } + + // Make sure to count the last token + if (tokenFound) + count++; + + // if counting delmiters add them into the token count + return retDelims ? count + delimiterCount : count; + } +} // class StringTokenizer |