car-di.java

class Car{
  private Wheels wheel;
  private Battery battery;
  
  /*Somewhere in our codebase we instatiate the objects required by this class.
    There are two methods for implementing DI:
    1. Constructor based
    2. Setter based
  */
  
  // Constructor Based
  Car(Wheel wh, Battery bt) {
    this.wh = wh;
    this.bt = bt;
  }
  
  // Setter Based
  void setWheel(Battery bt){
    this.bt = bt;
  }
  ...  
  ...
  // Rest of code  
}