com.jaxfront.core.util
Class StringTokenizer

java.lang.Object
  java.util.StringTokenizer
      com.jaxfront.core.util.StringTokenizer

All Implemented Interfaces:

java.util.Enumeration<java.lang.Object>

public class StringTokenizer
extends java.util.StringTokenizer

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 G10SICSStringTokenizer 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 G10SICSStringTokenizer behaves in one of two ways, depending on whether it was created with the returnTokens flag having the value true or false:

• If the flag is false, delimiter characters serve to separate tokens. A token is a maximal sequence of consecutive characters that are not delimiters.
• If the flag is true, delimiter characters are themselves considered to be tokens. A token is thus either one delimiter character, or a maximal sequence of consecutive characters that are not delimiters.

A G10SICSStringTokenizer 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 G10SICSStringTokenizer object.

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

 G10SICSStringTokenizer st = new G10SICSStringTokenizer("this is a test");
 while (st.hasMoreTokens()) {
        println(st.nextToken());
 }
 

prints the following output:

     this
     is
     a
     test
 

See Also:

StringTokenizer

Constructor Summary

StringTokenizer(java.lang.String str)
Constructs a string tokenizer for the specified string.

StringTokenizer(java.lang.String str, java.lang.String delim)
Constructs a string tokenizer for the specified string.

StringTokenizer(java.lang.String str, java.lang.String delim, boolean returnTokens)
Constructs a string tokenizer for the specified string.

StringTokenizer(java.lang.String str, java.lang.String delim, boolean returnTokens, boolean emptyReturnTockenIsNull)
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	hasMorePreviousTokens() Tests if there are more tokens available from this tokenizer's string.
boolean	hasMoreTokens() Tests if there are more tokens available from this tokenizer's string.
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.
java.lang.String	previousToken() Returns the next token from this string tokenizer.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StringTokenizer

public StringTokenizer(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.

StringTokenizer

public StringTokenizer(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.

StringTokenizer

public StringTokenizer(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.

StringTokenizer

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

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.

Method Detail

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.

Overrides:

countTokens in class java.util.StringTokenizer

Returns:

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

See Also:

java.util.G10SICSStringTokenizer#nextToken()

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<java.lang.Object>

Overrides:

hasMoreElements in class java.util.StringTokenizer

Returns:

true if there are more tokens; false otherwise.

See Also:

Enumeration, java.util.G10SICSStringTokenizer#hasMoreTokens()

hasMorePreviousTokens

public boolean hasMorePreviousTokens()

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.

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.

Overrides:

hasMoreTokens in class java.util.StringTokenizer

Returns:

true if and only if there is at least one token in the string after the current position; 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<java.lang.Object>

Overrides:

nextElement in class java.util.StringTokenizer

Returns:

the next token in the string.

Throws:

java.util.NoSuchElementException - if there are no more tokens in this tokenizer's string.

See Also:

Enumeration, java.util.G10SICSStringTokenizer#nextToken()

nextToken

public java.lang.String nextToken()

Returns the next token from this string tokenizer.

Overrides:

nextToken in class java.util.StringTokenizer

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 G10SICSStringTokenizer 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.

Overrides:

nextToken in class java.util.StringTokenizer

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.

previousToken

public java.lang.String previousToken()

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.