Error using . stream(). filter in JAVA

Question

I am developing an application in which it aims to create a list that respects the condition of being of type = "unit". In the code below, I create the list and from a function I try to generate this list.

code of the class Productmovement

package teste1;

public class ProductMovement {
    private int id;
    private String nome;

    public ProductMovement(int id, String nome) {

        this.id = id;
        this.nome = nome;
    }

    public ProductMovement() {


    }

    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getNome() {
        return nome;
    }
    public void setNome(String nome) {
        this.nome = nome;
    }

}

code of class Teste1

package teste1;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Stream;

import teste1.ProductMovement;



public class Teste {

    @SuppressWarnings("unchecked")
    private static  List<ProductMovement> filterFractionedMovements(List<ProductMovement> reservMovements) {

        return (List<ProductMovement>) reservMovements.stream().filter(px -> px.getNome().equals("unidade"));
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
         // Creating a list 

            List<ProductMovement> pro = Arrays.asList(new ProductMovement(1,"unidade"),
                    new ProductMovement(2,"caixa"),  
                    new ProductMovement(3,"unidade"),
                    new ProductMovement(4,"caixa"));

            //Stream<ProductMovement> ProductMovements = pro.stream();
            //Integer idTipoProduto = ProductMovements.filter(px -> px.getNome().equals("unidade")).mapToInt(px -> px.getId()).sum();
            //System.out.println(idTipoProduto);    

            //lista somente 
            List<ProductMovement> lista = filterFractionedMovements(pro);
            lista.forEach(element -> System.out.println(element));

    }
}

Error message:

Exception in thread "main" java.lang.Classcastexception: java.util.stream.Referencepipeline$2 cannot be cast to java.util.List at teste1.Teste.filterFractionedMovements(Test.java:17) at teste1.Teste.main(Test.java:34)

Answer 1

All Stream methods return another Stream. To turn back into a list, you need to use a Collector:

<Seu stream>.collect(Collectors.toList());