| Frames | No Frames |
1: /* StringTokenizer -- breaks a String into tokens 2: Copyright (C) 1998, 1999, 2001, 2002, 2005 Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package java.util; 40: 41: /** 42: * This class splits a string into tokens. The caller can set on which 43: * delimiters the string should be split and if the delimiters should be 44: * returned. This is much simpler than {@link java.io.StreamTokenizer}. 45: * 46: * <p>You may change the delimiter set on the fly by calling 47: * nextToken(String). But the semantic is quite difficult; it even 48: * depends on calling <code>hasMoreTokens()</code>. You should call 49: * <code>hasMoreTokens()</code> before, otherwise the old delimiters 50: * after the last token are candidates for being returned. 51: * 52: * <p>If you want to get the delimiters, you have to use the three argument 53: * constructor. The delimiters are returned as token consisting of a 54: * single character. 55: * 56: * @author Jochen Hoenicke 57: * @author Warren Levy (warrenl@cygnus.com) 58: * @see java.io.StreamTokenizer 59: * @status updated to 1.4 60: */ 61: public class StringTokenizer implements Enumeration<Object> 62: { 63: // WARNING: StringTokenizer is a CORE class in the bootstrap cycle. See the 64: // comments in vm/reference/java/lang/Runtime for implications of this fact. 65: 66: /** 67: * The position in the str, where we currently are. 68: */ 69: private int pos; 70: 71: /** 72: * The string that should be split into tokens. 73: */ 74: private final String str; 75: 76: /** 77: * The length of the string. 78: */ 79: private final int len; 80: 81: /** 82: * The string containing the delimiter characters. 83: */ 84: private String delim; 85: 86: /** 87: * Tells, if we should return the delimiters. 88: */ 89: private final boolean retDelims; 90: 91: /** 92: * Creates a new StringTokenizer for the string <code>str</code>, 93: * that should split on the default delimiter set (space, tab, 94: * newline, return and formfeed), and which doesn't return the 95: * delimiters. 96: * 97: * @param str The string to split 98: * @throws NullPointerException if str is null 99: */ 100: public StringTokenizer(String str) 101: { 102: this(str, " \t\n\r\f", false); 103: } 104: 105: /** 106: * Create a new StringTokenizer, that splits the given string on 107: * the given delimiter characters. It doesn't return the delimiter 108: * characters. 109: * 110: * @param str the string to split 111: * @param delim a string containing all delimiter characters 112: * @throws NullPointerException if either argument is null 113: */ 114: public StringTokenizer(String str, String delim) 115: { 116: this(str, delim, false); 117: } 118: 119: /** 120: * Create a new StringTokenizer, that splits the given string on 121: * the given delimiter characters. If you set 122: * <code>returnDelims</code> to <code>true</code>, the delimiter 123: * characters are returned as tokens of their own. The delimiter 124: * tokens always consist of a single character. 125: * 126: * @param str the string to split 127: * @param delim a string containing all delimiter characters 128: * @param returnDelims tells, if you want to get the delimiters 129: * @throws NullPointerException if str or delim is null 130: */ 131: public StringTokenizer(String str, String delim, boolean returnDelims) 132: { 133: len = str.length(); 134: this.str = str; 135: this.delim = delim; 136: this.retDelims = returnDelims; 137: this.pos = 0; 138: } 139: 140: /** 141: * Tells if there are more tokens. 142: * 143: * @return true if the next call of nextToken() will succeed 144: */ 145: public boolean hasMoreTokens() 146: { 147: if (! retDelims) 148: { 149: while (pos < len && delim.indexOf(str.charAt(pos)) >= 0) 150: pos++; 151: } 152: return pos < len; 153: } 154: 155: /** 156: * Returns the nextToken, changing the delimiter set to the given 157: * <code>delim</code>. The change of the delimiter set is 158: * permanent, ie. the next call of nextToken(), uses the same 159: * delimiter set. 160: * 161: * @param delim a string containing the new delimiter characters 162: * @return the next token with respect to the new delimiter characters 163: * @throws NoSuchElementException if there are no more tokens 164: * @throws NullPointerException if delim is null 165: */ 166: public String nextToken(String delim) throws NoSuchElementException 167: { 168: this.delim = delim; 169: return nextToken(); 170: } 171: 172: /** 173: * Returns the nextToken of the string. 174: * 175: * @return the next token with respect to the current delimiter characters 176: * @throws NoSuchElementException if there are no more tokens 177: */ 178: public String nextToken() throws NoSuchElementException 179: { 180: if (pos < len && delim.indexOf(str.charAt(pos)) >= 0) 181: { 182: if (retDelims) 183: return str.substring(pos, ++pos); 184: while (++pos < len && delim.indexOf(str.charAt(pos)) >= 0) 185: ; 186: } 187: if (pos < len) 188: { 189: int start = pos; 190: while (++pos < len && delim.indexOf(str.charAt(pos)) < 0) 191: ; 192: 193: return str.substring(start, pos); 194: } 195: throw new NoSuchElementException(); 196: } 197: 198: /** 199: * This does the same as hasMoreTokens. This is the 200: * <code>Enumeration</code> interface method. 201: * 202: * @return true, if the next call of nextElement() will succeed 203: * @see #hasMoreTokens() 204: */ 205: public boolean hasMoreElements() 206: { 207: return hasMoreTokens(); 208: } 209: 210: /** 211: * This does the same as nextTokens. This is the 212: * <code>Enumeration</code> interface method. 213: * 214: * @return the next token with respect to the current delimiter characters 215: * @throws NoSuchElementException if there are no more tokens 216: * @see #nextToken() 217: */ 218: public Object nextElement() throws NoSuchElementException 219: { 220: return nextToken(); 221: } 222: 223: /** 224: * This counts the number of remaining tokens in the string, with 225: * respect to the current delimiter set. 226: * 227: * @return the number of times <code>nextTokens()</code> will succeed 228: * @see #nextToken() 229: */ 230: public int countTokens() 231: { 232: int count = 0; 233: int delimiterCount = 0; 234: boolean tokenFound = false; // Set when a non-delimiter is found 235: int tmpPos = pos; 236: 237: // Note for efficiency, we count up the delimiters rather than check 238: // retDelims every time we encounter one. That way, we can 239: // just do the conditional once at the end of the method 240: while (tmpPos < len) 241: { 242: if (delim.indexOf(str.charAt(tmpPos++)) >= 0) 243: { 244: if (tokenFound) 245: { 246: // Got to the end of a token 247: count++; 248: tokenFound = false; 249: } 250: delimiterCount++; // Increment for this delimiter 251: } 252: else 253: { 254: tokenFound = true; 255: // Get to the end of the token 256: while (tmpPos < len 257: && delim.indexOf(str.charAt(tmpPos)) < 0) 258: ++tmpPos; 259: } 260: } 261: 262: // Make sure to count the last token 263: if (tokenFound) 264: count++; 265: 266: // if counting delmiters add them into the token count 267: return retDelims ? count + delimiterCount : count; 268: } 269: } // class StringTokenizer