CODEWITHSUNDEEP
javacollectionsjava-8java-stream
Ashish
Ashish

Reputation: 1952

Stream Filter with individual collect

I have list of persons & each person has person type ie 10, 11, 12

I want to make sublist which has each of person type

With Streams I have achieved this with 3 iterations

Can group & get in 1 iteration ?

Person.java

public class Person {

    String personType;
    String name;

    public Person(String personType, String name) {
        this.personType = personType;
        this.name = name;
    }

    public String getPersonType() {
        return personType;
    }

    public void setPersonType(String personType) {
        this.personType = personType;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "Person{" +
                "personType='" + personType + '\'' +
                ", name='" + name + '\'' +
                '}';
    }
}

Driver.java

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class Driver {

    public static void main(String[] args) {

        List<Person> persons = populateList();

         List<Person> persons1 =  persons.stream().filter( p -> p.getPersonType().equals("10")).collect(Collectors.toList());
        List<Person> persons2 =  persons.stream().filter( p -> p.getPersonType().equals("10")).collect(Collectors.toList());
        List<Person> persons3 =  persons.stream().filter( p -> p.getPersonType().equals("10")).collect(Collectors.toList());

    }
    public static List<Person> populateList(){
            Person person01 = new Person("10","Tony");
            Person person02 = new Person("11","Steve");
            Person person03 = new Person("12","Banner");
            Person person04 = new Person("10","Thor");
            Person person05 = new Person("11","Natasha");
            Person person06 = new Person("12","Loki");
            Person person07 = new Person("10","Peter");
            Person person08 = new Person("11","HawkEye");
            Person person09 = new Person("12","Falcon");
            Person person10 = new Person("10","Jarvis");
        List<Person> persons = new ArrayList<>();
            persons.add(person01);
            persons.add(person02);
            persons.add(person03);
            persons.add(person04);
            persons.add(person05);
            persons.add(person06);
            persons.add(person07);
            persons.add(person08);
            persons.add(person09);
            persons.add(person10);
        return persons;
    }
}

Upvotes: 0

Views: 55

Answers (1)

cody123
cody123

Reputation: 2080

You can use group by.

Map<String, List<Person>> obj1 = persons.stream().collect(Collectors.groupingBy(Person :: getPersonType));
System.out.println(obj1);

Upvotes: 3

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