java regex pattern matcher code example

Example 1: java regex

import java.util.regex.*;  
public class RegexExample1{  
public static void main(String args[]){  
//1st way  
Pattern p = Pattern.compile(".s");//. represents single character  
Matcher m = p.matcher("as");  
boolean b = m.matches();  
  
//2nd way  
boolean b2=Pattern.compile(".s").matcher("as").matches();  
  
//3rd way  
boolean b3 = Pattern.matches(".s", "as");  
  
System.out.println(b+" "+b2+" "+b3);  
}}

Example 2: java regex matcher example

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

public class MatcherExample {

    public static void main(String[] args) {

        String text    =
            "This is the text to be searched " +
            "for occurrences of the http:// pattern.";

        String patternString = ".*http://.*";

        Pattern pattern = Pattern.compile(patternString);

        Matcher matcher = pattern.matcher(text);
        boolean matches = matcher.matches();
      
      	int count = 0;
        while(matcher.find()) {
            count++;
            System.out.println("found: " + count + " : "
                    + matcher.start() + " - " + matcher.end());
        }
    }
}

Example 3: pattern matching java

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

public class Solution {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int num = scanner.nextInt();
        String emailRegEx = ".+@gmail\\.com$";
        Pattern pattern = Pattern.compile(emailRegEx);
        List<String> list = new ArrayList();
        for (int i = 0; i < num; i++){
            String name = scanner.next();
            String email = scanner.next();
            Matcher matcher = pattern.matcher(email);
            if (matcher.find()){
                list.add(name);
            }
        }
        Collections.sort(list);
        for (String name : list){
            System.out.println(name);
        }
    }
}