How to find first non-repeatable character from a String using Java 8 ?

In this post we will learn How to find first non-repeatable character from a String using Java 8?

package com.kkjavatutorials.client;

import static java.util.function.Function.identity;

import java.util.LinkedHashMap;
import java.util.function.Consumer;
import java.util.stream.Collectors;

/**
 * @author KK JavaTutorials
 * This java program is all about how will you find first non-repeatable character from a String using Java 8
 */
public class FindFirstNonRepeatableCharacterInStringTest {
	public static void main(String[] args) {
		 findFirstNonRepeatingInString("KKJavaTutorials",System.out::println);
		 findFirstNonRepeatingInString("English",System.out::println);
	}

	private static void findFirstNonRepeatingInString(String inputText, Consumer<Character> callback) {
		     inputText.chars().mapToObj(i -> Character.valueOf((char) i))
				.collect(Collectors.groupingBy(identity(), LinkedHashMap::new, Collectors.counting())).entrySet()
				.stream().filter(entry -> entry.getValue() == 1L).map(entry -> entry.getKey()).findFirst().map(c -> {
					callback.accept(c);
					return c;
				});
		
	}
}

package com.kkjavatutorials.client;

import static java.util.function.Function.identity;

import java.util.LinkedHashMap;

import java.util.function.Consumer;

import java.util.stream.Collectors;

/**

* @author KK JavaTutorials

* This java program is all about how will you find first non-repeatable character from a String using Java 8

public class FindFirstNonRepeatableCharacterInStringTest {

public static void main(String[] args) {

findFirstNonRepeatingInString("KKJavaTutorials",System.out::println);

findFirstNonRepeatingInString("English",System.out::println);

}

private static void findFirstNonRepeatingInString(String inputText, Consumer<Character> callback) {

inputText.chars().mapToObj(i -> Character.valueOf((char) i))

.collect(Collectors.groupingBy(identity(), LinkedHashMap::new, Collectors.counting())).entrySet()

.stream().filter(entry -> entry.getValue() == 1L).map(entry -> entry.getKey()).findFirst().map(c -> {

callback.accept(c);

return c;

});

}

Sample output of above program:

J
E

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That’s all about Java Program to find first non-repeatable character from a String using Java 8 ?
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