public class StringTokenizerUtil extends Object implements Enumeration
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
:
false
, delimiter characters serve to
separate tokens. A token is a maximal sequence of consecutive
characters that are not delimiters.
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 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
Constructor and Description |
---|
StringTokenizerUtil(String str)
Constructs a string tokenizer for the specified string.
|
StringTokenizerUtil(String str,
String delim)
Constructs a string tokenizer for the specified string.
|
StringTokenizerUtil(String str,
String delim,
boolean returnTokens)
Constructs a string tokenizer for the specified string.
|
Modifier and Type | Method and Description |
---|---|
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(String[] args)
test main
|
Object |
nextElement()
Returns the same value as the
nextToken method,
except that its declared return value is Object rather than
String . |
String |
nextToken()
Returns the next token from this string tokenizer.
|
String |
nextToken(String delim)
Returns the next token in this string tokenizer's string.
|
public StringTokenizerUtil(String str, String delim, boolean returnTokens)
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.
str
- a string to be parsed.delim
- the delimiters.returnTokens
- flag indicating whether to return the delimiters
as tokens.public StringTokenizerUtil(String str, String delim)
delim
argument are the delimiters
for separating tokens. Delimiter characters themselves will not
be treated as tokens.str
- a string to be parsed.delim
- the delimiters.public StringTokenizerUtil(String str)
"\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.str
- a string to be parsed.public boolean hasMoreTokens()
true
if and only if there is at least one token
in the string after the current position; false
otherwise.public String nextToken()
NoSuchElementException
- if there are no more tokens in this
tokenizer's string.public String nextToken(String delim)
delim
- the new delimiters.NoSuchElementException
- if there are no more tokens in this
tokenizer's string.public boolean hasMoreElements()
hasMoreTokens
method. It exists so that this class can implement the
Enumeration
interface.hasMoreElements
in interface Enumeration
true
if there are more tokens;
false
otherwise.public Object nextElement()
nextToken
method,
except that its declared return value is Object
rather than
String
. It exists so that this class can implement the
Enumeration
interface.nextElement
in interface Enumeration
NoSuchElementException
- if there are no more tokens in this
tokenizer's string.public int countTokens()
nextToken
method can be called before it generates an
exception. The current position is not advanced.public static void main(String[] args)
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