The subexpression/metacharacter “( )” groups the regular expressions and remembers the matched text.Example 1import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example {    public static void main( String args[] ) {       String input = "Hello how are you welcome to Tutorialspoint";       String regex = "H(ell|ow)";       //Compiling the regular expression       Pattern pattern = Pattern.compile(regex);       //Retrieving the matcher object       Matcher matcher = pattern.matcher(input);       if(matcher.find()) {          System.out.println("Match found");       } else {       ... Read More

The subexpression/metacharacter “\B” matches the non-word boundaries.Example 1import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "\Bcause";       Scanner sc = new Scanner(System.in);       System.out.println("Enter a string: ");       String input = sc.nextLine();       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count ++;       }       System.out.println("Number of matches: "+count);    } ... Read More

The java.util.regex package of java provides various classes to find particular patterns in character sequences. The pattern class of this package is a compiled representation of a regular expression.To match a specific character from the given input string −Get the input string.This compile() method of this class accepts a string value representing a regular expression and an integer value representing a flag returns a Pattern object. Compile the regular expression bypassing −The pattern matcher “[ ]” with required character in it ex: “[t]”.The flag CASE_INSENSITIVE to ignore case.The matcher() method of the Pattern class accepts an input string and returns ... Read More

The pattern class of the java.regex package is a compiled representation of a regular expression.The compile() method of this class accepts a string value representing a regular expression and returns a Pattern object.Exampleimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class CompileExample {    public static void main( String args[] ) {       //Reading string value       Scanner sc = new Scanner(System.in);       System.out.println("Enter input string");       String input = sc.nextLine();       //Regular expression to find digits       String regex = "(\d)";       //Compiling the regular expression ... Read More

The com.fasterxml.jackson.databind.node.ObjectNode class can be used to map the JSON object structure in Json content. We can search for a particular value inside the JSON file using the get() method of ObjectNode class, this method used for accessing the value of a specified field of an object node.Syntaxpublic JsonNode get(String fieldName)Exampleimport com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.node.ObjectNode; public class ObjectNodeTest {    public static void main(String args[]) throws Exception {       String jsonString = "{\"Id\":101, \"name\":\"Raja Ramesh\", \"address\":\"Madhapur\"}";       ObjectMapper mapper = new ObjectMapper();       ObjectNode node = mapper.readValue(jsonString, ObjectNode.class);       if(node.has("name")) {       ... Read More

The java.util.regex.Matcher class represents an engine that performs various match operations. There is no constructor for this class you can create/obtain an object of this class using the matches() method of the class java.util.regex.Pattern.The matches() method of this class matches the string with, the pattern represented by the regular expression (both given while creating this object). In the case of a match, this method returns true else it returns false. For the result of this method to be true, the entire region should have a match.Exampleimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class MatchesExample {    public static void main(String ... Read More

The java.util.regex.Matcher class represents an engine that performs various match operations. There is no constructor for this class you can create/obtain an object of this class using the matches() method of the class java.util.regex.Pattern.The find() method of this class tries to find the next subsequent input matching the current Matcher object, in case of the match this method returns true else it returns false.Exampleimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class FindExample {    public static void main( String args[] ) {       //Reading string value       Scanner sc = new Scanner(System.in);       System.out.println("Enter ... Read More

The java.util.regex.Matcher class represents an engine that performs various match operations. There is no constructor for this class you can create/obtain an object of this class using the matches() method of the class java.util.regex.Pattern.The end() method of the Matcher class returns the offset after the last match represented by the current object.The subexpression "[...]" matches the characters specified within the braces in the input string, In the following example using this to match the character t. Here, We have compiled the regular expression using the compile() method.Obtained the Matcher object.Invoked the matcher() method on each match.Exampleimport java.util.Scanner; import java.util.regex.Matcher; import ... Read More

The java.util.regex.Matcher class represents an engine that performs various match operations. There is no constructor for this class you can create/obtain an object of this class using the matches() method of the class java.util.regex.Pattern.The start() method of the Matcher class returns the starting index of the matched character.ExampleThe subexpression "[...]" matches the characters specified within the braces in the input string, In the following example using this to match the character t. Here, We have compiled the regular expression using the compile() method.Obtained the Matcher object.Invoked the matcher() method on each match.Exampleimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class StartExample ... Read More

You can match the non-word boundaries using the meta character “\B”.Example 1import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example {    public static void main(String args[]) {       //Reading String from user       System.out.println("Enter a String");       Scanner sc = new Scanner(System.in);       String input = sc.nextLine();       String regex = "\B";       //Compiling the regular expression       Pattern pattern = Pattern.compile(regex);       //Retrieving the matcher object       Matcher matcher = pattern.matcher(input);       int count = 0;     ... Read More