com.plumtree.openfoundation.util
Class XPStringTokenizer

java.lang.Object
  com.plumtree.openfoundation.util.XPStringTokenizer

public class XPStringTokenizer

extends java.lang.Object

The string tokenizer class allows an application to break a string into tokens. The XPStringTokenizer 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 XPStringTokenizer behaves in one of two ways, depending on whether it was created with the returnDelims 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 XPStringTokenizer 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 XPStringTokenizer object.

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

     XPStringTokenizer st = new XPStringTokenizer("this is a test");
     while (st.hasMoreTokens()) {
         XPSystem.out.Write(st.nextToken());
     }
 

prints the following output:

     this
     is
     a
     test
 

Constructor Summary

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

XPStringTokenizer(java.lang.String str, java.lang.String delimiter)
Constructs a string tokenizer for the specified string.

XPStringTokenizer(java.lang.String str, java.lang.String delimiter, boolean returnDelims)
Constructs a string tokenizer for the specified string.

Method Summary

java.lang.String	GetNextElement() Returns the same value as the nextToken method, except that its declared return value is Object rather than String.
java.lang.String	GetNextToken() Returns the next token from this string tokenizer.
int	GetTokenCount() Calculates the number of times that this tokenizer's nextToken method can be called before it generates an exception.
boolean	HasMoreElements() It exists so that this class can implement the Enumeration interface.
boolean	HasMoreTokens() Tests if there are more tokens available from this tokenizer's string.

Methods inherited from class java.lang.Object

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

Constructor Detail

XPStringTokenizer

public XPStringTokenizer(java.lang.String str)

Constructs a string tokenizer for the specified string. The tokenizer uses the default delimiter set, 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.

XPStringTokenizer

public XPStringTokenizer(java.lang.String str,
                         java.lang.String delimiter)

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.

delimiter - the delimiters.

XPStringTokenizer

public XPStringTokenizer(java.lang.String str,
                         java.lang.String delimiter,
                         boolean returnDelims)

Constructs a string tokenizer for the specified string. All characters in the delim argument are the delimiters for separating tokens.

If the returnDelims 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.

Note that if delim is null, this constructor does not throw an exception. However, trying to invoke other methods on the resulting StringTokenizer may result in a NullPointerException.

Parameters:

str - a string to be parsed.

delimiter - the delimiters.

returnDelims - flag indicating whether to return the delimiters as tokens.

Method Detail

GetTokenCount

public int GetTokenCount()

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.

HasMoreElements

public boolean HasMoreElements()

It exists so that this class can implement the Enumeration interface.

Returns:

true if there are more tokens; 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.

Returns:

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

GetNextElement

public java.lang.String GetNextElement()

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.

Returns:

the next token in the string.

GetNextToken

public java.lang.String GetNextToken()

Returns the next token from this string tokenizer.

Returns:

the next token from this string tokenizer.

Throws:

XPNoSuchElementException - if there are no more tokens in this tokenizer's string.