When use java regular-expression pattern.matcher(), source does not match regex.But, my hope result is ,source matches regex

java string matches regex
java regular expression tester
java regex special characters
java regex example
groovy regular expression tester
java 8 regex
java regex cheat sheet
java regex; matcher

When use java regular-expression pattern.matcher(), source does not match regex.But, my hope result is ,source matches regex.

  • String source = "ONE.TWO"
  • String regex = "^ONE\\.TWO\\..*"

    import java.util.regex.Pattern;

    public class Test {
        public static void main(String[] args) {
            test();
        }

        public static void test() {
            Test stringDemo = new Test();
            stringDemo.testMatcher();
        }

        public void testMatcher() {
            String source = "ONE.TWO";
            String regex = "^ONE\\.TWo\\..*";
            // The result = false, "not match". But, the hope result is true, "match"
            matcher(source, regex);
        }

        public void matcher(String source, String regex) {
            Pattern pattern = Pattern.compile(regex);

            boolean match = pattern.matcher(source).matches();
            if (match) {
                System.out.println("match");
            } else {
                System.out.println("not match");
            }
        }
    }

In your code, your regular expression expects the o in TWO to be lower case and expects it to be followed by a ..

Try:

String source = "ONE.TWo.";

This will match your regular expression as coded in your question.

The expression \. means match a literal dot (rather than any character). When you code this into a Java String, you have to escape the backslash with another backslash, so it becomes "\\.".

The .* on the end of the expression means "match zero or more of any character (except line-break)".

So this would also match:

String source = "ONE.TWo.blah blah";

Regular expressions in Java - Tutorial, When use java regular-expression pattern.matcher(), source does not match regex.But, my hope result is ,source matches regex. String source = "ONE.TWO  All in one Java Regex, Matcher Pattern and Regular Expressions Tutorial Last Updated on September 30th, 2017 by App Shah Leave a comment In this tutorial we will go over list of Matcher ( java.util.regex.Matcher ) APIs.

Regular Expressions and the Java Programming Language, The pattern defined by the regex may match one or several times or not Once a source character has been used in a match, it cannot be of the following examples use JUnit Tutorial to validate the result. Common matching symbols regular expressions, i.e., the matches() , split()) , replaceFirst() and  That regex is a bit stronger than yours - it checks for whole words (no partial matches), and gets rid of any number of consecutive repetitions. The regex captures a first word: \b(\w+)\b, and then attempts to match spaces and repetitions of that word: (\s+\1)+. The final \b is to avoid partial matching of \1, as in "for formatting". more

Pattern matching is case sensitive by Default. In your case source has a uppercase O and regex a lowercase o.

So you have to add Pattern.CASE_INSENSITIVE or Change the case of o

Pattern pattern = Pattern.compile(regex,Pattern.CASE_INSENSITIVE );

or

String regex = "^ONE\\.TWO\\..*";

Pattern (Java Platform SE 7 ), To pattern match using the Java programming language required the use of the This article provides an overview of the use of regular expressions, and details Regular expression matching also allows you to test whether a string fits into a If you don't care for one of the available sources, you can write your own input  Regular expressions are used for defining String patterns that can be used for searching, manipulating and editing a text. These expressions are also known as Regex (short form of Regular expressions). In the below example, the regular expression .*book.* is used for searching the occurrence of string “book” in the text.

Your regex is a bit incorrect. You have an extra dot here:

String regex = "^ONE\.TWO\.(extra dot).*"

Try this one, without dot:

String regex = "^ONE\.TWO.*"

Groovy Regular Expressions, The resulting pattern can then be used to create a Matcher object that can This method compiles an expression and matches an input sequence against string literals in Java source code are interpreted as required by The Java™ By default, the regular expressions ^ and $ ignore line terminators and only match at the  The result of a match operation. This interface contains query methods used to determine the results of a match against a regular expression. The match boundaries, groups and group boundaries can be seen but not modified through a MatchResult.

String regex = "^ONE\\.TWO\\..*"

The DOUBLE SLASH \\ in regex is escape sequence to match a SINGLE SLASH \ in Source string.

The .* at the end matches any character 0 or More times except line breaks.

To match the regex your source should be like

String source = "ONE\.TWO\three blah @#$ etc" OR
String source = "ONE\.TWO\.123@#$ etc"

Basically its Any String which starts with ONE\.TWO\ and without line breaks.

Everything you need to know about Regular Expressions, I always found working with regular expressions in Java kind error-prone. String (if it has no variables to interpolate) or groovy.lang.GString This pattern extracts both the matching word and the letter. In Groovy, we can use spread operator to call first() method on each element to extract matching words. The Java Matcher class (java.util.regex.Matcher) is used to search through a text for multiple occurrences of a regular expression.You can also use a Matcher to search for the same regular expression in different texts.

You Should Learn Regex, You'll get a true or false result indicating whether the string belongs to the set of zip The above pattern matches foo.csv , but does not match bar.txt or my_csv_file . Before you use regular expressions in your code, you can test them using an It may contain literals, character classes, boundary matchers,  Regular expressions can be used to search, edit and manipulate text. The process of analyzing or modifying a text with a regex is called: The regular expression is applied to the text/string . The pattern defined by the regex is applied on the text from left to right. Once a source character has been used in a match, it cannot be reused. For

Finding Comments in Source Code Using Regular Expressions , A regular expression (or regex, or regexp) is a way to describe complex The source code for the examples in this tutorial can be found at the Github We could replace [0-9] with \d , which will do the same thing (match any digit). The great thing about this expression (and regular expressions in general)  The following are top voted examples for showing how to use java.util.regex.Matcher.These examples are extracted from open source projects. You can vote up the examples you like and your votes will be used in our system to generate more good examples.

How-To: Regular Expressions in Java (Part 1), This feature is allows one to find text based on complex patterns rather than based just does not implement the "non-greedy matching" feature of regular expressions. This regular expression will match them both along with anything in between: The solution is to still accept any character that is not * , but also accept a  Since java regular expression revolves around String, String class has been extended in Java 1.4 to provide a matches method that does regex pattern matching. Internally it uses Pattern and Matcher java regex classes to do the processing but obviously it reduces the code lines. Pattern class also contains matches method that takes regex and

Comments
  • Why your hope is "true" ? ^^ because it just can't work for many reason, and the easier one is 'W' does not match 'w'
  • It works for me. Thank U. I can not modify String regex = "^ONE\\.TWO\\..*" ,Because it is response of one API request. But I can modify my use source: boolean match = pattern.matcher(source).matches() || pattern.matcher(source + ".").matches();
  • I can not modify String regex = "^ONE\\.TWO\\..*" ,Because it is response of one API request. But, Thank U all the same.
  • @Vicky So you need to adapt the Regex to match it.
  • Yes. regex list is the api response. this regex list is useful for most data. Only Two regex is not useful. I must write extral custom regex for the sepecial case.
  • I can not modify String regex = "^ONE\\.TWO\\..*" ,Because it is response of one API request. But, Thank U all the same.
  • I can not modify String regex = "^ONE\\.TWO\\..*" ,Because it is response of one API request. But, Thank U all the same.
  • no. backslash must be escaped once for java, and eventually once for the regexp engine (if you need to match a dot, eg. "\\\\."). "\." is an invalid Java string. this code doesn't compile.