With this example we are going to demonstrate how to use Matcher.lookingAt()
API method to match an input sequence, starting at the beginning of the input, against a specified pattern. In short, to match a Sting input against a pattern with Matcher.lookingAt()
API method you should:
- Compile a String regular expression to a Pattern, using
compile(String regex)
API method of Pattern. - Use
matcher(CharSequence input)
API method of Pattern to create a Matcher that will match the given String input against this pattern. - Use
lookingAt()
API method of Matcher to match the input against the pattern, starting from the beginning of the input, but without requiring that the entire region be matched. - Reset the matcher with a new input sequence with
reset(CharSequence input)
API method to match a new String input against the pattern.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core; import java.util.regex.Matcher; import java.util.regex.Pattern; public class MatcherLookingAt { public static void main(String args[]) { Pattern pattern = Pattern.compile("J2SE"); String str1 = "J2SE is the only one for me"; String str2 = "For me, it's J2SE, or nothing at all"; String str3 = "J2SEistheonlyoneforme"; Matcher m = pattern.matcher(str1); String msg = ":" + str1 + ": matches?: "; System.out.println(msg + m.lookingAt()); m.reset(str2); msg = ":" + str2 + ": matches?: "; System.out.println(msg + m.lookingAt()); m.reset(str3); msg = ":" + str3 + ": matches?: "; System.out.println(msg + m.lookingAt()); } }
Output:
:J2SE is the only one for me: matches?: true
:For me, it's J2SE, or nothing at all: matches?: false
:J2SEistheonlyoneforme: matches?: true
This was an example of Matcher.lookingAt()
API method in Java.