Chapter 17
The java.util Package

StringTokenizer

Name

StringTokenizer

Synopsis

Class Name:

java.util.StringTokenizer

Superclass:

java.lang.Object

Immediate Subclasses:

None

Interfaces Implemented:

java.util.Enumeration

Availability:

JDK 1.0 or later

The StringTokenizer class implements a simple, delimiter-based string tokenizer. In other words, a StringTokenizer is used to break a String into tokens separated by delimiter characters. By default, the class uses the standard whitespace characters as delimiters, but you can specify any delimiter characters you want, either when the StringTokenizer is created or on a token-by-token basis. You can also specify whether the delimiters are returned as tokens or not. A StringTokenizer returns the tokens in its String in order, either as String objects or as Objects in an Enumeration.

StringTokenizer shouldn't be confused with the more complex java.io.StreamTokenizer, which parses a stream into tokens that are similar to those used in the Java language.

Class Summary

public class java.util.StringTokenizer extends java.lang.Object
             implements java.util.Enumeration {
  // Constructors
  public StringTokenizer(String str);
  public StringTokenizer(String str, String delim);
  public StringTokenizer(String str, String delim, boolean returnTokens);
  // Instance Methods
  public int countTokens();
  public boolean hasMoreElements();
  public boolean hasMoreTokens();
  public Object nextElement();
  public String nextToken();
  public String nextToken(String delim);
}

Constructors

StringTokenizer

public StringTokenizer(String str)

Parameters

str: The String to be tokenized.

Description

This constructor creates a StringTokenizer that breaks apart the given string using the default delimiter characters. The default delimiters are the standard whitespace characters: space, tab (\t), carriage return (\r), and newline (\n).

public StringTokenizer(String str, String delim)

Parameters

str

The String to be tokenized.

delim

The delimiter characters.

Description

This constructor creates a StringTokenizer that breaks apart the given string using the characters in delim as delimiter characters.

 public StringTokenizer(String str, String delim, boolean returnTokens)

Parameters

str

The String to be tokenized.

delim

The delimiter characters.

returnTokens

A boolean value that indicates whether or not delimiters should be returned as tokens.

Description

This constructor creates a StringTokenizer that breaks apart the given string using the characters in delim as delimiter characters. If returnTokens is true, the delimiters are returned as tokens; otherwise they are skipped.

Instance Methods

countTokens

public int countTokens()

Returns

The number of tokens remaining in the string.

Description

This method returns the number of tokens that remain in the string, which is the same as the number of times nextToken() can be called before an exception is thrown.

hasMoreElements

public boolean hasMoreElements()

Returns

true if there are more tokens to be returned; false otherwise.

Implements

Enumeration.hasMoreElements()

Description

This method returns the result of calling hasMoreTokens().

hasMoreTokens

public boolean hasMoreTokens()

Returns

true if there are more tokens to be returned; false otherwise.

Description

This method returns true if this object has more tokens to return.

nextElement

public Object nextElement()

Returns

The next token as an Object.

Throws

NoSuchElementException: If there are no more tokens in the string.

Implements

Enumeration.nextElement()

Description

This method returns result of calling nextToken().

nextToken

public String nextToken()

Returns

The next token as a String.

Throws

NoSuchElementException: If there are no more tokens in the string.

Description

This method returns the next token.

public String nextToken(String delim)

Parameters

delim: The delimiter characters.

Returns

The next token as a String.

Throws

NoSuchElementException: If there are no more tokens in the string.

Description

This method sets the delimiter characters to the characters in the given string and then returns the next token. The change in delimiters persists until another call to this method changes them again.

Inherited Methods

Method	Inherited From	Method	Inherited From
`clone()`	`Object`	`equals(Object)`	`Object`
`finalize()`	`Objxect`	`getClass()`	`Object`
`hashCode()`	`Object`	`notify()`	`Object`
`notifyAll()`	`Object`	`toString()`	`Object`
`wait()`	`Object`	`wait(long)`	`Object`
`wait(long, int)`	`Object`