The PatternCompiler interface defines the operations a regular
expression compiler must implement. However, the types of
regular expressions recognized by a compiler and the Pattern
implementations produced as a result of compilation are not
restricted.
A PatternCompiler instance is used to compile the string representation
(either as a String or char[]) of a regular expression into a Pattern
instance. The Pattern can then be used in conjunction with the appropriate
PatternMatcher instance to perform pattern searches. A form
of use might be:
PatternCompiler compiler;
PatternMatcher matcher;
Pattern pattern;
String input;
// Initialization of compiler, matcher, and input omitted;
try {
pattern = compiler.compile("\\d+");
} catch(MalformedPatternException e) {
System.out.println("Bad pattern.");
System.out.println(e.getMessage());
System.exit(1);
}
if(matcher.matches(input, pattern))
System.out.println(input + " is a number");
else
System.out.println(input + " is not a number");
Specific PatternCompiler implementations such as Perl5Compiler may have
variations of the compile() methods that take extra options affecting
the compilation of a pattern. However, the PatternCompiler method
implementations should provide the default behavior of the class.
compile(char[] pattern)
Compiles a regular expression into a data structure that can be used
by a PatternMatcher implementation to perform pattern matching.
compile(char[] pattern,
int options)
Compiles a regular expression into a data structure that can be
used by a PatternMatcher implementation to perform pattern matching.
compile(java.lang.String pattern)
Compiles a regular expression into a data structure that can be used
by a PatternMatcher implementation to perform pattern matching.
compile(java.lang.String pattern,
int options)
Compiles a regular expression into a data structure that can be
used by a PatternMatcher implementation to perform pattern matching.
Compiles a regular expression into a data structure that can be used
by a PatternMatcher implementation to perform pattern matching.
Parameters:
pattern - A regular expression to compile.
Returns:
A Pattern instance constituting the compiled regular expression.
Throws:
MalformedPatternException - If the compiled expression
does not conform to the grammar understood by the PatternCompiler or
if some other error in the expression is encountered.
Compiles a regular expression into a data structure that can be
used by a PatternMatcher implementation to perform pattern matching.
Additional regular expression syntax specific options can be passed
as a bitmask of options.
Parameters:
pattern - A regular expression to compile.
options - A set of flags giving the compiler instructions on
how to treat the regular expression. The flags
are a logical OR of any number of the allowable
constants permitted by the PatternCompiler
implementation.
Returns:
A Pattern instance constituting the compiled regular expression.
Throws:
MalformedPatternException - If the compiled expression
does not conform to the grammar understood by the PatternCompiler or
if some other error in the expression is encountered.
Compiles a regular expression into a data structure that can be used
by a PatternMatcher implementation to perform pattern matching.
Parameters:
pattern - A regular expression to compile.
Returns:
A Pattern instance constituting the compiled regular expression.
Throws:
MalformedPatternException - If the compiled expression
does not conform to the grammar understood by the PatternCompiler or
if some other error in the expression is encountered.
Compiles a regular expression into a data structure that can be
used by a PatternMatcher implementation to perform pattern matching.
Additional regular expression syntax specific options can be passed
as a bitmask of options.
Parameters:
pattern - A regular expression to compile.
options - A set of flags giving the compiler instructions on
how to treat the regular expression. The flags
are a logical OR of any number of the allowable
constants permitted by the PatternCompiler
implementation.
Returns:
A Pattern instance constituting the compiled regular expression.
Throws:
MalformedPatternException - If the compiled expression
does not conform to the grammar understood by the PatternCompiler or
if some other error in the expression is encountered.