Write a program to find the only duplicate count list in the List
Categories: Java 9 Java 8(JDK1.8) Java Java Examples
package r4r.co.in;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collectors;
public class OnlyDuplicateCountList {
public static void main(String[] args) {
// Write a program to find the only duplicate count list in the List
List<String> list = List.of("Rajesh", "Kumar", "Verma", "Verma", "Rani", "Prisha", "Prisha", "Verma", "Rani");
Map<String, Long> map = list.stream().filter(d -> Collections.frequency(list, d) > 1)
.collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));
System.err.println(map);
}
}
Output
{Rani=2, Verma=3, Prisha=2}