设计模式学习心得——one

背景

最近在工作中，要处理分布式多组件间的通信反馈问题，但是因为没有学习过设计模式，导致了编码实现的功能健壮性很差，并且难以维护，自己都理不清整个流程的逻辑细节。

面对这种情况，开始学习《Head First 设计模式》这本书。并将学到的模型记录下来。接下来学第一个设计模式：

策略模式

设计原则汇总

1. 找出应用中可能需要变化之处，把他们独立出来，不要和那些不需要变化的代码混在一起。
2. 针对接口编程，而不是针对实现编程。
3. 多用组合，少用继承。

代码实现

1.Duck.java

package lesson1;

/**
* Created by willard on 17/4/4.
*/
public abstract class Duck {

FlyBehavior flyBehavior;
QuackBehavior quackBehavior;

public Duck() {

}

public abstract void display();

public void performFly() {
flyBehavior.fly();
}

public void performQuack() {
quackBehavior.quack();
}

public void swim() {
System.out.println("All ducks float, even decoys!");
}

public void setFlyBehavior(FlyBehavior flyBehavior) {
this.flyBehavior = flyBehavior;
}

public void setQuackBehavior(QuackBehavior quackBehavior) {
this.quackBehavior = quackBehavior;
}
}

2.FlyBehavior.java

package lesson1;

/**
* Created by willard on 17/4/4.
*/
public interface FlyBehavior {
public void fly();
}

3.FlyNoWings.java

package lesson1;

/**
* Created by willard on 17/4/4.
*/
public class FlyNoWings implements FlyBehavior {
@Override
public void fly() {
System.out.println("I can't fly.");
}
}

4.FlyRocketPowered.java

package lesson1;

/**
* Created by willard on 17/4/4.
*/
public class FlyRocketPowered implements FlyBehavior {
@Override
public void fly() {
System.out.println("I'm flying with a rocket!");
}
}

5.FlyWithWings.java

package lesson1;

/**
* Created by willard on 17/4/4.
*/
public class FlyWithWings implements FlyBehavior {
@Override
public void fly() {
System.out.println("I'm flying!!");
}
}

6.MallardDuck.java

package lesson1;

/**
* Created by willard on 17/4/4.
*/
public class MallardDuck extends Duck {

public MallardDuck() {
quackBehavior = new Quack();
flyBehavior = new FlyWithWings();
}

@Override
public void display() {
System.out.println("I'm a real Mallard duck");
}

}

7.MiniDuckSimulator.java

package lesson1;

/**
* Created by willard on 17/4/4.
*/
public class MiniDuckSimulator {
public static void main(String[] args) {
Duck mallard = new MallardDuck();
mallard.performQuack();
mallard.performFly();

Duck model = new ModelDuck();
model.performFly();
model.setFlyBehavior(new FlyRocketPowered());
model.performFly();
}
}

8.ModelDuck.java

package lesson1;

/**
* Created by willard on 17/4/4.
*/
public class ModelDuck extends Duck {
public ModelDuck() {
flyBehavior = new FlyNoWings();
quackBehavior = new Quack();
}

@Override
public void display() {
System.out.println("I'm a model duck");
}
}

9.MuteQuack.java

package lesson1;

/**
* Created by willard on 17/4/4.
*/
public class MuteQuack implements QuackBehavior {
@Override
public void quack() {
System.out.println("<< Silence >>");
}
}

10.Quack.java

package lesson1;

/**
* Created by willard on 17/4/4.
*/
public class Quack implements QuackBehavior {
@Override
public void quack() {
System.out.println("Quack");
}
}

11.QuackBehavior.java

package lesson1;

/**
* Created by willard on 17/4/4.
*/
public interface QuackBehavior {
public void quack();
}

12.Squeak.java

package lesson1;

/**
* Created by willard on 17/4/4.
*/
public class Squeak implements QuackBehavior {
@Override
public void quack() {
System.out.println("Squea");
}
}

结构关系图

待补充......