JAVA EE: How to get name values from a list of Software engineer objects using Java 8 streams

Thursday, 31 August 2017

How to get name values from a list of Software engineer objects using Java 8 streams

Click here to watch in Youtube :
https://www.youtube.com/watch?v=c47IfvJPRUo&list=UUhwKlOVR041tngjerWxVccw

SoftwareEngineer.java

public class SoftwareEngineer
{
    private String name;
    private int age;
    private int salary;

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

    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;
    }

    public int getSalary()
    {
        return salary;
    }

    public void setSalary(int salary)
    {
        this.salary = salary;
    }

}

StreamDemo.java

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

/**
List of objects -> List of String
Get all the name values from a list of the SoftwareEngineer objects.
*/

public class StreamDemo
{
    public static void main(String[] args)
    {

        List<SoftwareEngineer> softwareEngineerList = Arrays.asList(
                new SoftwareEngineer("Ram", 30, 10000),
                new SoftwareEngineer("Peter", 27, 20000),
                new SoftwareEngineer("Jai", 33, 30000));

        // Before Java 8
        List<String> nameList = new ArrayList<String>();
        for (SoftwareEngineer softwareEngineer : softwareEngineerList)
        {
            nameList.add(softwareEngineer.getName());
        }
        System.out.println(nameList);

        // Java 8
        List<String> collectNameList = softwareEngineerList.stream()
                                                .map(softwareEngineer -> softwareEngineer.getName())
                                                .collect(Collectors.toList());
        System.out.println(collectNameList);

    }

}