Find out words occurrences in a file

In the previous post, we have seen how to find common elements among 2 unsorted arrays. In this post, we will see how to get the count of same word occurrences in a file.

Find out words occurrences in a file:

There are few steps given below that need to be followed.

• Create a object for file
• Read it using Buffered Reader
• Create a Map of String and Integer as key and value respectively
• Keep increasing the counter if key matches more than once
• Display keys and their values

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

public class FindWordsOccurances {

	public static BufferedReader bufferedReader= null;
	static String  inputLine = null;
	static String key = null;
	static int value = 0;
	public static void main(String[] args) throws FileNotFoundException {
		File file = new File("C://Personal//New folder/Sample.txt");
		bufferedReader = new BufferedReader(new FileReader(file));
		
		//Create a map for counting word occurrences 
		Map<String,Integer> CountMap = new HashMap<>();
		
		try {
			while ((inputLine = bufferedReader.readLine()) != null) {
				//create an array by splitting the line
				String[] wordsArr = inputLine.split("[ \n\t\r.,;:!?(){}]");
 
				for (int counter = 0; counter < wordsArr.length; counter++) {
					 key = wordsArr[counter].toLowerCase();  //Convert into lowercase to make it case insensitive
					if (key.length() > 0) {               // If key does not exist then assign value 1
						if (CountMap.get(key) == null) {
							CountMap.put(key, 1);
						} else {
							int value = CountMap.get(key).intValue();    // If key already exists then increase value by 1
							value++;
							CountMap.put(key, value);
						}
					}
				}
				
			}
		
		}catch(Exception e){
			System.out.println(e.getMessage());
		}
		
		//Create an entry set to read key and value
		for(Entry<String, Integer> s : CountMap.entrySet())
		System.out.println(s.getKey()+"-- "+s.getValue());
	}
}

Output: