Program: Java regex with case insensitive.

We need to pass Pattern.CASE_INSENSITIVE constant to Pattern.compile() method, along with regular expression. This makes case insensitive matches.

package com.java2novice.regex;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class MyPatternMatchCaseInsensitive {

	public boolean isPatternMatching(String line){
		
		Pattern ptn = Pattern.compile("java", Pattern.CASE_INSENSITIVE);
		Matcher mtch = ptn.matcher(line);
		if(mtch.find()){
			return true;
		}
		return false;
	}
	
	public static void main(String a[]){
		MyPatternMatchCaseInsensitive msp = new MyPatternMatchCaseInsensitive();
		System.out.println(msp.isPatternMatching("This line contains java, lets see"));
		System.out.println(msp.isPatternMatching("Here JAVA is in capital leters, lets see"));
		System.out.println(msp.isPatternMatching("Here C++ is in capital leters, lets see"));
	}
}

true
true
false