JAVA EE: How to filter the List of Person based on Gender using Java 8 Stream

Wednesday, 27 September 2017

How to filter the List of Person based on Gender using Java 8 Stream | Streams in Java 8

Click here to watch in Youtube :
https://www.youtube.com/watch?v=DQVdAQPUkuk&list=UUhwKlOVR041tngjerWxVccw

Person.java

enum Gender
{
    MALE, FEMALE
}

public class Person
{
    private String name;
    private String email;
    private Gender gender;
    private int age;

    public Person(String name, String email, Gender gender, int age)
    {
        super();
        this.name = name;
        this.email = email;
        this.gender = gender;
        this.age = age;
    }

    public String getName()
    {
        return name;
    }

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

    public String getEmail()
    {
        return email;
    }

    public void setEmail(String email)
    {
        this.email = email;
    }

    public Gender getGender()
    {
        return gender;
    }

    public void setGender(Gender gender)
    {
        this.gender = gender;
    }

    public int getAge()
    {
        return age;
    }

    public void setAge(int age)
    {
        this.age = age;
    }

    @Override
    public String toString()
    {
        return "Person [name=" + name + ", gender=" + gender + ", age=" + age
                + "]";
    }

}

StreamFilterDemo.java

import java.util.ArrayList;
import java.util.List;

public class StreamFilterDemo
{
    public static void main(String[] args)
    {
        List<Person> personList = new ArrayList<>();

        personList.add(new Person("Alice","alice@gmail.com",Gender.FEMALE, 16));
        personList.add(new Person("Bob","bob@gmail.com", Gender.MALE, 15));
        personList.add(new Person("Carol","carol@gmail.com",Gender.FEMALE, 23));
        personList.add(new Person("David","david@gmail.com",    Gender.MALE, 19));
        personList.add(new Person("Eric","eric@gmail.com", Gender.MALE, 26));
        
        System.out.println("--------Filterd based on FEMALE--------");
        
        /*
         * The filter() operation returns a new stream that consists elements
         * matching a given condition which is typically a boolean test in form
         * of a Lambda expression.
         * 
         * The following code lists only female persons:
         */
        personList.stream().filter(p -> p.getGender().equals(Gender.FEMALE))
                                                .forEach(System.out::println);
        
        
        System.out.println("\n--------Filterd based on Male and Age<=25--------");
        
        /*
         * The following code shows only male who are under 25:
         */
        personList.stream().filter(p -> p.getGender().equals(Gender.MALE) && p.getAge() <= 25)
                .forEach(System.out::println);

    }

}

Output

--------Filterd based on FEMALE--------
Person [name=Alice, gender=FEMALE, age=16]
Person [name=Carol, gender=FEMALE, age=23]

--------Filterd based on Male and Age<=25--------
Person [name=Bob, gender=MALE, age=15]
Person [name=David, gender=MALE, age=19]