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package com.activemesa.solid.dip;

import org.javatuples.Triplet;

import java.util.ArrayList;

import java.util.List;

import java.util.Objects;

import java.util.stream.Collectors;

// A. High-level modules should not depend on low-level modules.

// Both should depend on abstractions.

// B. Abstractions should not depend on details.

// Details should depend on abstractions.

enum Relationship

{

PARENT,

CHILD,

SIBLING

}

class Person

{

public String name;

// dob etc.

public Person(String name) {

this.name = name;

}

}

interface RelationshipBrowser

{

List<Person> findAllChildrenOf(String name);

}

class Relationships implements RelationshipBrowser

{

public List<Person> findAllChildrenOf(String name) {

return relations.stream()

.filter(x -> Objects.equals(x.getValue0().name, name)

&& x.getValue1() == Relationship.PARENT)

.map(Triplet::getValue2)

.collect(Collectors.toList());

}

// Triplet class requires javatuples

private List<Triplet<Person, Relationship, Person>> relations =

new ArrayList<>();

public List<Triplet<Person, Relationship, Person>> getRelations() {

return relations;

}

public void addParentAndChild(Person parent, Person child)

{

relations.add(new Triplet<>(parent, Relationship.PARENT, child));

relations.add(new Triplet<>(child, Relationship.CHILD, parent));

}

}

class Research

{

public Research(Relationships relationships)

{

// high-level: find all of john's children

List<Triplet<Person, Relationship, Person>> relations = relationships.getRelations();

relations.stream()

.filter(x -> x.getValue0().name.equals("John")

&& x.getValue1() == Relationship.PARENT)

.forEach(ch -> System.out.println("John has a child called " + ch.getValue2().name));

}

public Research(RelationshipBrowser browser)

{

List<Person> children = browser.findAllChildrenOf("John");

for (Person child : children)

System.out.println("John has a child called " + child.name);

}

}

class DIPDemo

{

public static void main(String[] args)

{

Person parent = new Person("John");

Person child1 = new Person("Chris");

Person child2 = new Person("Matt");

// low-level module

Relationships relationships = new Relationships();

relationships.addParentAndChild(parent, child1);

relationships.addParentAndChild(parent, child2);

new Research(relationships);

}

}