Java 8

 package com.java8.functional;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Comparator;

import java.util.List;

import java.util.function.BinaryOperator;

import java.util.function.Function;

import java.util.function.Predicate;

import java.util.stream.Collectors;

public class Test {

// Functional interfaces

// -Predicate

// -BinaryOpeator

// -Function

public static void main(String[] args) {

// -Predicate

Predicate<String> strPrd=(s)->s.equals("baya");

Predicate<String> strPrd1=(s)->s.equals("baya1");

System.out.println(strPrd.or(strPrd1).test("baya1"));

List<Integer> list = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);

 

Predicate<Integer> even=(i)->i%2==0; 

 

System.out.println(list.stream().filter(even).collect(Collectors.toList()));

System.out.println(list.stream().filter(even.negate()).collect(Collectors.toList()));

 

// -BinaryOpeator

BinaryOperator<Integer> sum=(i,j)->i+j;

 

 

System.out.println(sum.apply(10, 20));

System.out.println(list.stream().reduce(sum).get());

System.out.println(list.stream().reduce(BinaryOperator.minBy(Integer::compare)).get());

System.out.println(list.stream() .reduce( Integer::max).get());

 

// -Function

Function<Integer,Integer> multiplyBy2=(v)->v*2;

 

System.out.println(multiplyBy2.apply(10));

System.out.println(list.stream().map(multiplyBy2).collect(Collectors.toList()));

 

 

List<Emp> empList=new ArrayList<>();

empList.add(new Emp(10,"Baya",1000f,1));

empList.add(new Emp(11,"Baya1",1000f,4));

empList.add(new Emp(12,"Baya2",1000f,3));

empList.add(new Emp(13,"Baya3",1000f,5));

empList.add(new Emp(14,"Baya4",1000f,1));

empList.add(new Emp(15,"Baya5",1000f,6));

 

empList.forEach(System.out::println);

 

Predicate<Emp> greaterThan3=(e)->e.grade>3;

Function<Emp,Emp> hikeMapper=(e)->{e.sal=e.sal+e.sal*10/100; return e;};

System.out.println(empList.stream().filter(greaterThan3).map(hikeMapper).collect(Collectors.toList()));

}

/*Developer dev1 = new Developer("jordan", BigDecimal.valueOf(9999));

    Developer dev2 = new Developer("jack", BigDecimal.valueOf(8888));

    Developer dev3 = new Developer("jaden", BigDecimal.valueOf(10000));

    Developer dev4 = new Developer("ali", BigDecimal.valueOf(2000));

    Developer dev5 = new Developer("mkyong", BigDecimal.valueOf(1));

    List<Developer> list = Arrays.asList(dev1, dev2, dev3, dev4, dev5);

    // 1. Create a Comparator

    Comparator<Developer> comparing = Comparator.comparing(Developer::getSalary);

    // 2. BinaryOperator with a custom Comparator

    BinaryOperator<Developer> bo = BinaryOperator.maxBy(comparing);

    Developer result = find(list, bo);

    System.out.println(result);     // Developer{name='jaden', salary=10000}

    // one line

    // find developer with highest pay

    Developer developer = find(list, BinaryOperator.maxBy(Comparator.comparing(Developer::getSalary)));

    System.out.println(developer);  // Developer{name='jaden', salary=10000}

    // find developer with lowest pay

    Developer developer2 = find(list, BinaryOperator.minBy(Comparator.comparing(Developer::getSalary)));

    System.out.println(developer2); // Developer{name='mkyong', salary=1}

}

public static Developer find(List<Developer> list, BinaryOperator<Developer> accumulator) {

    Developer result = null;

    for (Developer t : list) {

        if (result == null) {

            result = t;

        } else {

            result = accumulator.apply(result, t);

        }

    }

    return result;

}*/