/* * 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 java.util; /** * Breaks a string into tokens; new code should probably use {@link String#split}. * *
*
 * // Legacy code:
 * StringTokenizer st = new StringTokenizer("a:b:c", ":");
 * while (st.hasMoreTokens()) {
 *     System.err.println(st.nextToken());
 * }
 *
 * // New code:
 * for (String token : "a:b:c".split(":")) {
 *     System.err.println(token);
 * }
 * 
*
* * @since 1.0 */ public class StringTokenizer implements Enumeration { private String string; private String delimiters; private boolean returnDelimiters; private int position; /** * Constructs a new {@code StringTokenizer} for the parameter string using * whitespace as the delimiter. The {@code returnDelimiters} flag is set to * {@code false}. * * @param string * the string to be tokenized. */ public StringTokenizer(String string) { this(string, " \t\n\r\f", false); } /** * Constructs a new {@code StringTokenizer} for the parameter string using * the specified delimiters. The {@code returnDelimiters} flag is set to * {@code false}. If {@code delimiters} is {@code null}, this constructor * doesn't throw an {@code Exception}, but later calls to some methods might * throw a {@code NullPointerException}. * * @param string * the string to be tokenized. * @param delimiters * the delimiters to use. */ public StringTokenizer(String string, String delimiters) { this(string, delimiters, false); } /** * Constructs a new {@code StringTokenizer} for the parameter string using * the specified delimiters, returning the delimiters as tokens if the * parameter {@code returnDelimiters} is {@code true}. If {@code delimiters} * is null this constructor doesn't throw an {@code Exception}, but later * calls to some methods might throw a {@code NullPointerException}. * * @param string * the string to be tokenized. * @param delimiters * the delimiters to use. * @param returnDelimiters * {@code true} to return each delimiter as a token. */ public StringTokenizer(String string, String delimiters, boolean returnDelimiters) { if (string == null) { throw new NullPointerException("string == null"); } this.string = string; this.delimiters = delimiters; this.returnDelimiters = returnDelimiters; this.position = 0; } /** * Returns the number of unprocessed tokens remaining in the string. * * @return number of tokens that can be retreived before an {@code * Exception} will result from a call to {@code nextToken()}. */ public int countTokens() { int count = 0; boolean inToken = false; for (int i = position, length = string.length(); i < length; i++) { if (delimiters.indexOf(string.charAt(i), 0) >= 0) { if (returnDelimiters) count++; if (inToken) { count++; inToken = false; } } else { inToken = true; } } if (inToken) count++; return count; } /** * Returns {@code true} if unprocessed tokens remain. This method is * implemented in order to satisfy the {@code Enumeration} interface. * * @return {@code true} if unprocessed tokens remain. */ public boolean hasMoreElements() { return hasMoreTokens(); } /** * Returns {@code true} if unprocessed tokens remain. * * @return {@code true} if unprocessed tokens remain. */ public boolean hasMoreTokens() { if (delimiters == null) { throw new NullPointerException("delimiters == null"); } int length = string.length(); if (position < length) { if (returnDelimiters) return true; // there is at least one character and even if // it is a delimiter it is a token // otherwise find a character which is not a delimiter for (int i = position; i < length; i++) if (delimiters.indexOf(string.charAt(i), 0) == -1) return true; } return false; } /** * Returns the next token in the string as an {@code Object}. This method is * implemented in order to satisfy the {@code Enumeration} interface. * * @return next token in the string as an {@code Object} * @throws NoSuchElementException * if no tokens remain. */ public Object nextElement() { return nextToken(); } /** * Returns the next token in the string as a {@code String}. * * @return next token in the string as a {@code String}. * @throws NoSuchElementException * if no tokens remain. */ public String nextToken() { if (delimiters == null) { throw new NullPointerException("delimiters == null"); } int i = position; int length = string.length(); if (i < length) { if (returnDelimiters) { if (delimiters.indexOf(string.charAt(position), 0) >= 0) return String.valueOf(string.charAt(position++)); for (position++; position < length; position++) if (delimiters.indexOf(string.charAt(position), 0) >= 0) return string.substring(i, position); return string.substring(i); } while (i < length && delimiters.indexOf(string.charAt(i), 0) >= 0) i++; position = i; if (i < length) { for (position++; position < length; position++) if (delimiters.indexOf(string.charAt(position), 0) >= 0) return string.substring(i, position); return string.substring(i); } } throw new NoSuchElementException(); } /** * Returns the next token in the string as a {@code String}. The delimiters * used are changed to the specified delimiters. * * @param delims * the new delimiters to use. * @return next token in the string as a {@code String}. * @throws NoSuchElementException * if no tokens remain. */ public String nextToken(String delims) { this.delimiters = delims; return nextToken(); } }