Java Composition vs. Java Inheritance

01_Java_Composition_Car.java

public class Car {
 //private variables 
 private String color;
 private int maxSpeed;

 public void carInfo() {
  System.out.println("Car Color= " + color + " Max Speed= " + maxSpeed);
 }

 public void setColor(String color) {
  this.color = color;
 }

 public void setMaxSpeed(int maxSpeed) {
  this.maxSpeed = maxSpeed;
 }
}

02_Java_Composition_Racecar.java

public class Racecar extends Car {
 public void startRacecar() {
  Engine NASCAR_engine = new Engine();
  NASCAR_engine.start();
 }
}

03_Java_Composition_Engine.java

public class Engine {
 public void start() {
  System.out.println("Engine Started:");
 }

 public void stop() {
  System.out.println("Engine Stopped:");
 }
}

04_Java_Composition_Programmer.java

public class Programmer {
 private String name;
 private int age;
 private char gender;
 private Computer computer;

 public Programmer(String name, int age, char gender) {
  this.name = name;
  this.age = age;
  this.gender = gender;
  this.computer = new Computer();
  computer.setType("Mac");
  computer.setRAM(32);
  computer.setProcessorSpeed(4.3);
  computer.setStorageCapacity(512);
 }

 public String getType() {
  return computer.getType();
 }

 public int getRAM() {
  return computer.getRAM();
 }

 public int getStorage() {
  return computer.getStorageCapacity();
 }

 public double getProcessor() {
  return computer.getProcessorSpeed();
 }

 public void getComputer() {
  computer.getComputerInfo();
 }

 public void start() {
  computer.startUp();
 }

 public void reboot() {
  computer.sudoReboot();
 }

 public void shutdown() {
  computer.sudoShutdown();
 }

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

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

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

 public void getProgrammerInfo() {
  System.out.println("Programmer: " + "\n[Name]= " + name + "\n[Age]= " + age + " years old" + "\n[Gender]= " + gender);
 }

}

05_Java_Composition_Computer.java

public class Computer {
  private String type;
  private int RAM;
  private int storage_capacity;
  private double processor_speed;

  public void getComputerInfo() {
    System.out.println("Computer: " + "\n[Type]= " + type + "\n[RAM]= " + RAM + " GB" + "\n[Storage Capacity]= "
        + storage_capacity + "\n[Processor Speed]= " + processor_speed + " GHz");
  }

  public void setType(String type) {
    this.type = type;
  }

  public String getType() {
    return type;
  }

  public void setRAM(int RAM) {
    this.RAM = RAM;
  }

  public int getRAM() {
    return RAM;
  }

  public void setStorageCapacity(int storage_capacity) {
    this.storage_capacity = storage_capacity;
  }

  public int getStorageCapacity() {
    return storage_capacity;
  }

  public void setProcessorSpeed(double processor_speed) {
    this.processor_speed = processor_speed;
  }

  public double getProcessorSpeed() {
    return processor_speed;
  }

  public void startUp() {
    System.out.println("Mac Starting Up... Welcome!");
  }

  public void sudoReboot() {
    System.out.println("Mac Rebooting... See you soon.");
  }

  public void sudoShutdown() {
    System.out.println("Mac Shutting Down... Goodbye.");
  }
}

06_Java_Composition_Coding.java

public class Coding {
 public static void main(String[] args) {
  Programmer employee_001 = new Programmer("Bryan", 28, 'M');
  Computer c_001 = new Computer();
  System.out.println();
  employee_001.getProgrammerInfo();
  System.out.println();
  c_001.getComputerInfo();
  System.out.println();
  c_001.startUp();
  System.out.println();
  System.out.println("Upgrading processor speed...\n");
  c_001.setProcessorSpeed(5.5);
  System.out.println("New processor speed= " + c_001.getProcessorSpeed());
 }
}