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Java web设计模式

时间:2019-05-09 09:22:27      阅读:150      评论:0      收藏:0      [点我收藏+]

标签:事件对象   list   sig   span   stat   ffffff   ==   tin   round   

1.单例模式

是一种常用的软件设计模式,在它的核心结构中值包含一个被称为单例的特殊类。一个类只有一个实例,即一个类只有一个对象实例。

package design.pattern;

public class Singleton {

    private static Singleton singleton;

    private Singleton() {}

    public static Singleton getInstance() {

        if (singleton == null) {

            synchronized (Singleton.class) {

                singleton = new Singleton();

            }

        }

        return singleton;

    }

}

=============================================

2.工厂模式

package design.pattern;

public class MyFactory {

public static final int TYPE_MI = 1;// 大米

public static final int TYPE_YU = 2;// 油

public static final int TYPE_SC = 3;// 蔬菜

public static Food getFoods(int foodType) {

switch (foodType) {

case TYPE_MI:

return new DaMi();

case TYPE_YU:

return new You();

case TYPE_SC:

default:

return new ShuCai();

}

}

}

abstract class Food {

}

class DaMi extends Food {

}

class You extends Food {

}

class ShuCai extends Food {

}

=============================================

3.适配器模式

将一个类的接口转换成客户希望的另外一个接口。通俗地讲,就是在2个类之间做了一个衔接。比如你在调用A类的doSomething方法,实际上内部实现调用了B类的doSomething方法。

package design.pattern;

public class MyAdapter {

private MyAdapterImpl adapterImpl;

public MyAdapter(MyAdapterImpl myAdapterImpl) {

this.adapterImpl = myAdapterImpl;

}

public void doSomething() {

adapterImpl.doSomething();

}

public static void main(String args[]) {

new MyAdapter(new MyAdapterImpl()).doSomething();

}

}

class MyAdapterImpl {

public void doSomething() {

}

}

=============================================

4.代理模式

它的定义是:代理模式给某一个对象提供一个代理对象,并由代理对象控制对原对象的引用。Java的反射机制,很多地方就用了代理模式来实现。

package design.pattern;

import java.lang.reflect.InvocationHandler;

import java.lang.reflect.Method;

import java.lang.reflect.Proxy;

public class DynamicProxyMain {

public static void main(String[] args) {

Person smallPerson = new Child();

Person proxyBuyHouse = (Person) Proxy.newProxyInstance(Person.class.getClassLoader(),new Class[] { Person.class }, new DynamicProxyHandler(smallPerson));

proxyBuyHouse.eat();

}

}

interface Person {

void eat();

}

class Child implements Person {

@Override

public void eat() {

// 小孩吃什么

System.out.println("eating");

}

}

class DynamicProxyHandler implements InvocationHandler {

private Object object;

public DynamicProxyHandler(final Object object) {

this.object = object;

}

@Override

public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

System.out.println("调用前日志监控");

Object result = method.invoke(object, args);

System.out.println("调用后日志监控");

return result;

}

}

=============================================

5.监听模式

当事件源触发某种行为,会自动执行事件监听器里面相应的方法。Java监听模式右三个部分组成:事件源、事件对象、事件监听器。

package design.pattern;

public class ListenerTest {

public static void main(String[] args) {

MyListener myListener = new MyListener();

MyPerson person = new MyPerson();

person.addEatListener(myListener);

person.eat();

}

}

//事件源

class MyPerson{

private Listener listener;//监听器引用

//给事件源添加监听器

public void addEatListener(Listener listener) {

this.listener = listener;

}

public void eat() {

//吃了很多

if(listener != null) {

Event event=new Event() ;

event.setPerson(this);

listener.isThinking(event);//监听吃饭时,想了什么

}

}

}

//事件

class Event {

private MyPerson person;// 事件源的引用

public MyPerson getPerson() {

return person;

}

public void setPerson(MyPerson person) {

this.person = person;

}

}

interface Listener {

public void isThinking(Event event);

}

class MyListener implements Listener {

@Override

public void isThinking(Event event) {

System.out.println(" is isThinking many things !");

}

}

=============================================

6.装饰器模式

简单说就是不改变现有类的结构前提下,扩展它的功能。用别的类来增加原有类的功能

package design.pattern;

public class MyDecorator {

public static void main(String[] args) {

Animal animal= new SmallDog(new Pet());

animal.eat();

}

}

interface Animal {

public void eat();

}

class Pet implements Animal {

@Override

public void eat() {

System.out.println("eat food");

}

}

class Dog implements Animal{

protected Animal animal;

public Dog(Animal animal) {

this.animal = animal;

}

@Override

public void eat() {

this.animal.eat();

}

}

class SmallDog extends Dog{

public SmallDog(Animal animal) {

super(animal);

}

public void eat() {

System.out.println("eat other food ");

this.animal.eat();

}

}

Java web设计模式

标签:事件对象   list   sig   span   stat   ffffff   ==   tin   round   

原文地址:https://www.cnblogs.com/-liwu/p/10836493.html

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