/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.cocoon.util;
import java.util.Enumeration;
import java.util.NoSuchElementException;
/**
* Replacement for StringTokenizer in java.util, because of bug in the
* Sun's implementation.
*
* @deprecated Use commons lang. This class will be removed in 2.2.
* @author <A HREF="mailto:moravek@pobox.sk">Peter Moravek</A>
* @version CVS $Id$
*/
public class Tokenizer implements Enumeration {
/**
* Constructs a string tokenizer for the specified string. All characters
* in the delim argument are the delimiters for separating tokens.
* If the returnTokens flag is true, then the delimiter characters are
* also returned as tokens. Each delimiter is returned as a string of
* length one. If the flag is false, the delimiter characters are skipped
* and only serve as separators between tokens.
*
* @param str a string to be parsed
* @param delim the delimiters
* @param returnTokens flag indicating whether to return the delimiters
* as tokens
*/
public Tokenizer(String str, String delim, boolean returnTokens) {
this.str = str;
this.delim = delim;
this.returnTokens = returnTokens;
max = str.length();
}
/**
* Constructs a string tokenizer for the specified string. The characters
* in the delim argument are the delimiters for separating tokens.
* Delimiter characters themselves will not be treated as tokens.
*
* @param str a string to be parsed
* @param delim the delimiters
*/
public Tokenizer(String str, String delim) {
this(str, delim, false);
}
/**
* Constructs a string tokenizer for the specified string. The character
* in the delim argument is the delimiter for separating tokens.
* Delimiter character themselves will not be treated as token.
*
* @param str a string to be parsed
* @param delim the delimiter
*/
public Tokenizer(String str, char delim) {
this(str, String.valueOf(delim), false);
}
/**
* Constructs a string tokenizer for the specified string. The tokenizer
* uses the default delimiter set, which is " \t\n\r\f": 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
*/
public Tokenizer(String str) {
this(str, DEFAULT_DELIMITERS, false);
}
/**
* Tests if there are more tokens available from this tokenizer's string.
* If this method returns true, then a subsequent call to nextToken with
* no argument will successfully return a token.
*
* @return true if and only if there is at least one token in the string
* after the current position; false otherwise.
*/
public boolean hasMoreTokens() {
return ((current < max) ? (true) :
(((current == max) && (max == 0
|| (returnTokens && delim.indexOf(str.charAt(previous)) >= 0)))));
}
/**
* 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
*/
public String nextToken() throws NoSuchElementException {
if (current == max
&& (max == 0
|| (returnTokens && delim.indexOf(str.charAt(previous)) >= 0))) {
current++;
return "";
}
if (current >= max)
throw new NoSuchElementException();
int start = current;
String result = null;
if (delim.indexOf(str.charAt(start)) >= 0) {
if (previous == -1 || (returnTokens && previous != current
&& delim.indexOf(str.charAt(previous)) >= 0)) {
result = "";
}
else if (returnTokens)
result = str.substring(start, ++current);
if (!returnTokens)
current++;
}
previous = start;
start = current;
if (result == null)
while (current < max && delim.indexOf(str.charAt(current)) < 0)
current++;
return result == null ? str.substring(start, current) : result;
}
/**
* Returns the next token in this string tokenizer's string. First, the
* set of characters considered to be delimiters by this Tokenizer
* object is changed to be the characters in the string delim.
* 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.
*/
public String nextToken(String delim) throws NoSuchElementException {
this.delim = delim;
return nextToken();
}
/**
* Returns the same value as the hasMoreTokens method. It exists so that
* this class can implement the Enumeration interface.
*
* @return true if there are more tokens; false otherwise.
*/
public boolean hasMoreElements() {
return hasMoreTokens();
}
/**
* Returns the same value as the nextToken method, except that its
* declared return value is Object rather than String. It exists so that
* this class can implement the Enumeration interface.
*
* @return the next token in the string
*
* @exception NoSuchElementException if there are no more tokens in this
* tokenizer's string
*/
public Object nextElement() {
return nextToken();
}
/**
* Calculates the number of times that this tokenizer's nextToken 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
*/
public int countTokens() {
int curr = current;
int count = 0;
for (int i = curr; i < max; i++) {
if (delim.indexOf(str.charAt(i)) >= 0)
count++;
curr++;
}
return count + (returnTokens ? count : 0) + 1;
}
/**
* Resets this tokenizer's state so the tokenizing starts from the begin.
*/
public void reset() {
previous = -1;
current = 0;
}
/**
* Constructs a string tokenizer for the specified string. All characters
* in the delim argument are the delimiters for separating tokens.
* If the returnTokens flag is true, then the delimiter characters are
* also returned as tokens. Each delimiter is returned as a string of
* length one. If the flag is false, the delimiter characters are skipped
* and only serve as separators between tokens. Then tokenizes the str
* and return an String[] array with tokens.
*
* @param str a string to be parsed
* @param delim the delimiters
* @param returnTokens flag indicating whether to return the delimiters
* as tokens
*
* @return array with tokens
*/
public static String[] tokenize(String str, String delim,
boolean returnTokens) {
Tokenizer tokenizer = new Tokenizer(str, delim, returnTokens);
String[] tokens = new String[tokenizer.countTokens()];
int i = 0;
while (tokenizer.hasMoreTokens()) {
tokens[i] = tokenizer.nextToken();
i++;
}
return tokens;
}
/**
* Default delimiters " \t\n\r\f":
* the space character, the tab character, the newline character,
* the carriage-return character, and the form-feed character.
*/
public static final String DEFAULT_DELIMITERS = " \t\n\r\f";
/**
* String to tokenize.
*/
private String str = null;
/**
* Delimiters.
*/
private String delim = null;
/**
* Flag indicating whether to return the delimiters as tokens.
*/
private boolean returnTokens = false;
/**
* Previous token start.
*/
private int previous = -1;
/**
* Current position in str string.
*/
private int current = 0;
/**
* Maximal position in str string.
*/
private int max = 0;
}