/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
import java.util.stream.* ;
import java.util.function.* ;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		List<String> words = Arrays.asList( "👋", "Welcome", "to", "the", "java", "world" );
 
		Map < Character , Long > charFrequency = 
			words
			.stream()  //Stream<String>
        	.flatMap( a -> a.chars().mapToObj( c -> (char) c ) )  // Stream<Character>
        	.collect(
        		Collectors.groupingBy( Function.identity(), Collectors.counting() ) 
        	);
 
		System.out.println( charFrequency ) ;
 
	}
}

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