Online Training Spring Hibernate Training in Delhi R Programming Training Course Big Data and Hadoop Training Java Training

Getting the Indices of a Matching Group in a Regular Expression

Here, in this section, you will find the lower and upper indices of the matching group of the text through the regular expression in Java. This section explains some method or APIs which have been used in the following program.

Ads

Tutorials   
How to read properties file in Java? Generate random numbers in Java Cloneable Interface in Java What is the flaw with the Stack class? List In Java Java Stack Example HashSet In Java Enumeration in java How to generate random number in java Iterator in java Queue in java Transient Java Keyword clone method in Java Java Queue example Logger in Java Java current date - How to get current date in Java Collection : LinkedList Example Collection : ArrayList Example Random alpha numeric string of fixed size Java List Iterator Example The Hashtable Class The BitSet class Java Vector Java Enumeration Data Structures in Java Java Transient Variable Java Date Format Example Java Properties File Example Map.Entry Java Interface Java Property File java preferences,Change the value of Preferences by user Retrieving a Preference Node Java hasNext Write Keys and Values to the Properties file in Java Get All Keys and Values of the Properties files in Java Properties file in Java Properties file in Java Determining If a Preference Node Contains a Specific Value Change the value of Preferences by user Clone method example in Java Implementing a Simple Event Notifier Determining When a Preference Node Is Added or Removed Listening for Changes to Preference Values in a Preference Node Importing Preferences Finding a Preference in a Preference Tree Retrieving the Parent and Child Nodes of a Preference Node Determining If a Preference Node Exists Removing a Preference Node Creating a Preference Node Getting the Maximum Size of a Preference Key and Value
Ads

Getting the Indices of a Matching Group in a Regular Expression

     

Here, in this section, you will find the lower and upper indices of the matching group of the text  through the regular expression in Java. This section explains some method or APIs which have been used in the following program.

Code Description:

Matcher.groupCount():
This method counts the matched string or text of the given group of the text or string.

Matcher.start(index):
Above method returns the starting index of the matching word.

Matcher.end(index):
This method returns the last position of the matching word.

String.subSequence(groupStart, groupEnd):
This method returns the character sequences from the given start index to the given end index of the string or text.

Here is the code of the program:

import java.util.regex.*;
import java.io.*;

public class IndicesOfGroupOfText{
  public static void main(String[] args){
  CharSequence inputStr = "abbabcd";
  String patternStr = "(a(b*))+(c*)";
  
  // Compile and use regular expression
  Pattern pattern = Pattern.compile(patternStr);
  Matcher matcher = pattern.matcher(inputStr);
  boolean matchFound = matcher.find();
  System.out.println("Complete string/text: " + inputStr);
  int a = 0;
  if(matchFound){
  // Get all groups for this match
  for(int i=0; i<=matcher.groupCount(); i++){
  a = a + 1;
  // Get the group's captured text
  String groupStr = matcher.group(i);
  System.out.println(groupStr);
  
  // Get the group's indices
  int groupStart = matcher.start(i);
  int groupEnd = matcher.end(i);
  System.out.println("Last index of the group of \'" 

+ groupStr + "\': " + groupStart + " " (groupEnd-1));
  
  // groupStr is equivalent to
  inputStr.subSequence(groupStart, groupEnd);
  }
  }
  if (a == 0){
  System.out.println("No match found.");
  System.exit(0);
  }
  }
}

Download this example.

Advertisements

Share on Google+Share on Google+

Getting the Indices of a Matching Group in a Regular Expression

Posted on: February 22, 2008 If you enjoyed this post then why not add us on Google+? Add us to your Circles

Advertisements

 

Discuss: Getting the Indices of a Matching Group in a Regular Expression  

Post your Comment


Your Name (*) :
Your Email :
Subject (*):
Your Comment (*):
  Reload Image
 
 
Comments:0

Ads

 

Ads