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
:
- 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 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 |
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.
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