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Using REGEX and Patterns in Java

Using REGEX and Patterns in Java

Java has a very powerful library for REGEX. A very basic usage of REGEX is being presented in the code snippet below and we can improve on this to develop complicated cases.

import java.util.regex.Matcher;import java.util.regex.Pattern;public class UnderstandingPatterns{   public static void main(String args[])   {      UnderstandingPatterns understandingPatterns = new UnderstandingPatterns();      understandingPatterns.proceed();   }      private void proceed()   {      String msg = "EmpID: 1501, EmpName: Sridhar";      String idHeader = "EmpID: ";      String nameHeader = "EmpName: ";      Pattern idPattern = Pattern.compile(idHeader);      Pattern namePattern = Pattern.compile(nameHeader);            Matcher idMatcher = idPattern.matcher(msg);      Matcher nameMatcher = namePattern.matcher(msg);      if(idMatcher.find() && nameMatcher.find()){         int startPos = idMatcher.end() +1;         int endPos = nameMatcher.start();         String idValue = msg.substring(idMatcher.end(), nameMatcher.start()-2);         String nameValue = msg.substring(nameMatcher.end());         System.out.println("Emp ID: " + idValue);         System.out.println("Emp Name: " + nameValue);      }   }}/*

Expected output:

[root@mypc]# java UnderstandingPatternsEmp ID: 1501Emp Name: Sridhar*/ 

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