JAVA EE: Lambda expression[How to filter the list of person using lambda expression

Thursday, 25 May 2017

Lambda expression[How to filter the list of person using lambda expression - Predicate and Consumer]

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https://www.youtube.com/watch?v=GcHBJnaT5RY&list=UUhwKlOVR041tngjerWxVccw

Person.java

public class Person
{
    private String name;
    private int age;

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

    public String getName()
    {
        return name;
    }

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

    public int getAge()
    {
        return age;
    }

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

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

}

LambdaPredicateConsumerDemo.java

import java.util.Arrays;
import java.util.List;
import java.util.function.Consumer;
import java.util.function.Predicate;

public class LambdaPredicateConsumerDemo
{
    public static void main(String[] args)
    {
        List<Person> personList = Arrays.asList(
                new Person("Carla", 33), new Person("Balu", 32),
                new Person("Bharth", 40), new Person("Ajay", 31));

        System.out.println("------------Name Starts with B---------");
        /*
         * Create a method that prints all people that have name
         * begins with B.
         */
        printNameBeginWith_B(personList,
                p -> p.getName().startsWith("B"),
                p -> System.out.println(p));

        System.out.println("----------------------------------------");

        printNameBeginWith_B(personList,
                p -> p.getName().startsWith("B"),
                p -> System.out.println(p.getName()));

        System.out.println("----------------------------------------");
        
        printNameBeginWith_B(personList,
                p -> p.getName().startsWith("B"),
                p -> System.out.println(p.getAge()));

    }

    private static void printNameBeginWith_B(List<Person> personList,
            Predicate<Person> predicate, Consumer<Person> consumer)
    {
        for (Person person : personList)
        {
            if (predicate.test(person))
            {
                consumer.accept(person);
            }
        }

    }

}

Output

------------Name Starts with B---------
Person [name=Balu, age=32]
Person [name=Bharth, age=40]
----------------------------------------
Balu
Bharth
----------------------------------------
32
40