一、什么是倒转?
二、什么是依赖倒转原则
依赖倒转(Dependence Inversion Principle ):
1.抽象不应该依赖于细节,细节应该依赖于抽象。
2.高层模块不依赖底层模块,两者都依赖抽象。
三、组装电脑
四、怎样做到依赖倒转
1.工厂方法模式
2.模板方法模式
3.迭代子模式
代码实现:
电脑:
/*
* 电脑
*/
public class Computer {
private MainBoard mainBoard;
private Memory memory;
private HardDisk harddisk;
public MainBoard getMainBoard() {
return mainBoard;
}
public void setMainBoard(MainBoard mainBoard) {
this.mainBoard = mainBoard;
}
public Memory getMemory() {
return memory;
}
public void setMemory(Memory memory) {
this.memory = memory;
}
public HardDisk getHarddisk() {
return harddisk;
}
public void setHarddisk(HardDisk harddisk) {
this.harddisk = harddisk;
}
public void display() {
mainBoard.doSomething();
memory.doSomething();
harddisk.doSomething();
}
}
主板:
/*
* 主板抽象类
*/
public abstract class MainBoard {
public abstract void doSomething();
}
硬盘:
/*
* 硬盘的抽象类
*/
public abstract class HardDisk {
public abstract void doSomething();
}
内存:
/*
* 内存的抽象类
*/
public abstract class Memory {
public abstract void doSomething();
}
主板实现:
/*
* 华硕主板
*/
public class HuaSuoMainBoard extends MainBoard{
public void doSomething() {
System.out.println("this is huasuoMainBoard");
}
}
public class WeiXingMainBoard extends MainBoard {
public void doSomething() {
System.out.println("this is weixingMainBoard");
}
}
硬盘实现:
public class XiJieHardDisk extends HardDisk {
public void doSomething() {
System.out.println("this is xijieHardDisk");
}
}
public class XiShuHardDisk extends HardDisk {
public void doSomething() {
System.out.println("this is xishuHardDisk");
}
}
内存实现:
public class JinBangMemory extends Memory {
public void doSomething() {
System.out.println("this is jinbangMemory");
}
}
public class JinShiDunMemory extends Memory {
public void doSomething() {
System.out.println("this is jinshidunMemory");
}
}
测试类:
public class MainClass {
public static void main(String[] args) {
Computer computer = new Computer();
computer.setMainBoard(new HuaSuoMainBoard());
computer.setMemory(new JinShiDunMemory());
computer.setHarddisk(new XiJieHardDisk());
computer.display();
System.out.println("-------------");
computer.setMainBoard(new WeiXingMainBoard());
computer.display();
}
}
测试结果:
this is huasuoMainBoard
this is jinshidunMemory
this is xijieHardDisk
-------------
this is weixingMainBoard
this is jinshidunMemory
this is xijieHardDisk