依赖倒置原则

1、依赖倒置的本质就是通过抽象（接口或者抽象类）使各个类或模块实现彼此独立。

public interface ICar{
		public void run();
	}
	
	public interface IDriver{
		public void drive(ICar car);
	}
	
	public class Driver implements IDriver{

		@Override
		public void drive(ICar car) {
			car.run();
		}
	}
	public class Benz implements ICar{

		@Override
		public void run() {
			System.out.println(" benz running");
			
		}
		
	}
	public class Bmw implements ICar{

		@Override
		public void run() {
			System.out.println(" bmw running");
			
		}
	}
	
	public void main(String[] args){
		IDriver wanglei = new Driver();
		ICar benz = new Benz();
		wanglei.drive(benz);
	}

　　依赖的三种写法：

1、构造函数传递依赖对象

public interface IDriver{
		public void drive();
	}
	
	public class Driver implements IDriver{
		private ICar mCar;
		
		public void Driver(ICar car){
			this.mCar = car;
		}

		@Override
		public void drive() {
			mCar.run();
		}
	}

　　

2、set方法传递依赖对象

public interface IDriver{
		public void drive();
		public void setCar(ICar car);
	}
	
	public class Driver implements IDriver{
		private ICar mCar;

		@Override
		public void drive() {
			mCar.run();
		}

		@Override
		public void setCar(ICar car) {
			this.mCar = car;
			
		}
	}

　　

3、接口声明依赖对象