jsky.util
Class StringTokenizerUtil

java.lang.Object
  extended by jsky.util.StringTokenizerUtil
All Implemented Interfaces:
java.util.Enumeration

public class StringTokenizerUtil
extends java.lang.Object
implements java.util.Enumeration

Modified version of the jdk1.2 StringTokenizer class that does not skip empty tokens. (See Bug Id 4140850 in the Java Bug Parade). The standard version ignores empty tokens. Below is the original doc. ( abrighto@eso.org).

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 StreamTokenizer class. The StringTokenizerUtil methods do not distinguish among identifiers, numbers, and quoted strings, nor do they recognize and skip comments.

The set of delimiters (the characters that separate tokens) may be specified either at creation time or on a per-token basis.

An instance of StringTokenizerUtil behaves in one of two ways, depending on whether it was created with the returnTokens flag having the value true or false:

A StringTokenizerUtil object internally maintains a current position within the string to be tokenized. Some operations advance this current position past the characters processed.

A token is returned by taking a substring of the string that was used to create the StringTokenizerUtil object.

The following is one example of the use of the tokenizer. The code:

     StringTokenizerUtil st = new StringTokenizerUtil("this is a test");
     while (st.hasMoreTokens()) {
         println(st.nextToken());
     }
 

prints the following output:

     this
     is
     a
     test
 

Since:
JDK1.0
Version:
1.19, 03/18/98
Author:
unascribed

Constructor Summary
StringTokenizerUtil(java.lang.String str)
          Constructs a string tokenizer for the specified string.
StringTokenizerUtil(java.lang.String str, java.lang.String delim)
          Constructs a string tokenizer for the specified string.
StringTokenizerUtil(java.lang.String str, java.lang.String delim, boolean returnTokens)
          Constructs a string tokenizer for the specified string.
 
Method Summary
 int countTokens()
          Calculates the number of times that this tokenizer's nextToken method can be called before it generates an exception.
 boolean hasMoreElements()
          Returns the same value as the hasMoreTokens method.
 boolean hasMoreTokens()
          Tests if there are more tokens available from this tokenizer's string.
static void main(java.lang.String[] args)
          test main
 java.lang.Object nextElement()
          Returns the same value as the nextToken method, except that its declared return value is Object rather than String.
 java.lang.String nextToken()
          Returns the next token from this string tokenizer.
 java.lang.String nextToken(java.lang.String delim)
          Returns the next token in this string tokenizer's string.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

StringTokenizerUtil

public StringTokenizerUtil(java.lang.String str,
                           java.lang.String delim,
                           boolean returnTokens)
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.

Parameters:
str - a string to be parsed.
delim - the delimiters.
returnTokens - flag indicating whether to return the delimiters as tokens.

StringTokenizerUtil

public StringTokenizerUtil(java.lang.String str,
                           java.lang.String delim)
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.

Parameters:
str - a string to be parsed.
delim - the delimiters.

StringTokenizerUtil

public StringTokenizerUtil(java.lang.String str)
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.

Parameters:
str - a string to be parsed.
Method Detail

hasMoreTokens

public boolean hasMoreTokens()
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.

Returns:
true if and only if there is at least one token in the string after the current position; false otherwise.

nextToken

public java.lang.String nextToken()
Returns the next token from this string tokenizer.

Returns:
the next token from this string tokenizer.
Throws:
java.util.NoSuchElementException - if there are no more tokens in this tokenizer's string.

nextToken

public java.lang.String nextToken(java.lang.String delim)
Returns the next token in this string tokenizer's string. First, the set of characters considered to be delimiters by this StringTokenizerUtil 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.

Parameters:
delim - the new delimiters.
Returns:
the next token, after switching to the new delimiter set.
Throws:
java.util.NoSuchElementException - if there are no more tokens in this tokenizer's string.

hasMoreElements

public boolean hasMoreElements()
Returns the same value as the hasMoreTokens method. It exists so that this class can implement the Enumeration interface.

Specified by:
hasMoreElements in interface java.util.Enumeration
Returns:
true if there are more tokens; false otherwise.

nextElement

public java.lang.Object nextElement()
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.

Specified by:
nextElement in interface java.util.Enumeration
Returns:
the next token in the string.
Throws:
java.util.NoSuchElementException - if there are no more tokens in this tokenizer's string.

countTokens

public int countTokens()
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.

Returns:
the number of tokens remaining in the string using the current delimiter set.

main

public static void main(java.lang.String[] args)
test main