策略模式
策略模式主要有两个类：
1.角色：作为使用各种策略的对象
2.策略：各种策略类统一的上层接口，定义统一的算法接口方法
角色通过 组合 的方式使用各种策略
实例1： 角色类：国王，王后 （角色） 策略类：各种武器
Character
package Strategy;
/**
* 角色抽象类
* 拥有武器，可以进行攻击
* @author TisaKong
* 2015-6-4
*/
public abstract class Character {
WeaponBehavior weapon;
abstract void fight();
public void setWeapon(WeaponBehavior weapon) {
this.weapon = weapon;
}
}
King
package Strategy;
public class King extends Character{
public King() {
weapon = new KnifeBehavior();
}
@Override
void fight() {
weapon.useWeapon();
}
}
Queen
package Strategy;
public class Queen extends Character {
public Queen() {
weapon = new BowAndArrowBehavior();
}
@Override
void fight() {
weapon.useWeapon();
}
}
weapon
package Strategy;
/**
* 武器接口
* @author TisaKong
* 2015-6-4
*/
public interface WeaponBehavior {
public void useWeapon();
}
Knife
package Strategy;
public class KnifeBehavior implements WeaponBehavior {
@Override
public void useWeapon() {
System.out.println("use knife to kill enemies!");
}
}
BowAndArrow
package Strategy;
public class BowAndArrowBehavior implements WeaponBehavior {
@Override
public void useWeapon() {
System.out.println("use BowAndArrow to kill enemies!");
}
}
客户端测试
package Strategy;
public class Client {
public static void main(String[] args) {
Character king = new King();
king.fight();
Character queen = new Queen();
queen.fight();
}
}
实例2：
顾客到商场购物
商品抽象类Things
package Strategy;
public abstract class Things {
protected String name;
protected double price;
public Things() {
}
public Things(String name , double price) {
this.name = name;
this.price = price;
}
abstract double discount(double originalPrice);
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
}
衣服Clothes
package Strategy;
public class Clothes extends Things{
public Clothes(String name, double price) {
super(name, price);
}
@Override
public double discount(double originalPrice) {
double paid = Discount.CLOTHES_DISCOUNT*originalPrice;
return paid;
}
}
裤子Pants
package Strategy;
public class Pants extends Things{
public Pants(String name, double price) {
super(name, price);
}
@Override
double discount(double originalPrice) {
return Discount.PANTS_DISCOUNT*originalPrice;
}
}
电子产品Electronics
package Strategy;
public class Electronics extends Things {
public Electronics(String name, double price) {
super(name, price);
}
@Override
double discount(double originalPrice) {
return Discount.ELECTRONICS_DISCOUNT*originalPrice;
}
}
商城Market
package Strategy;
public class Market {
Storage myStorage = new Storage();
/**
* 初始化时将货物装载入库
*/
public Market(){
myStorage.install();
}
/**
* 从仓库中提取货物
* @return
*/
public Things getClothesFormStorage(){
Clothes clothes = myStorage.clothesStorage.get(0);
myStorage.clothesStorage.remove(0);
return clothes ;
}
public Things getPantsFormStorage(){
Pants pants = myStorage.pantsStorage.get(0);
myStorage.pantsStorage.remove(0);
return pants ;
}
public Things getElectronicsFormStorage(){
Electronics electronics = myStorage.electronicsStorage.get(0);
myStorage.electronicsStorage.remove(0);
return electronics ;
}
public Things buy(String name) {
//购买产品的类型
Things product = null;
if(name.equalsIgnoreCase("clothes")){
product = this.getClothesFormStorage();
product.setPrice(product.discount(product.getPrice()));
}
else if(name.equalsIgnoreCase("pants")){
product = this.getPantsFormStorage();
product.setPrice(product.discount(product.getPrice()));
}
else if(name.equalsIgnoreCase("electronics")){
product = this.getElectronicsFormStorage();
product.setPrice(product.discount(product.getPrice()));
}
return product;
}
}
商城的商品储藏室
package Strategy;
import java.util.ArrayList;
import java.util.List;
public class Storage {
/*
* 仓库内衣服的数量
*/
private static int NUM_CLOTHES = 100;
/*
* 仓库内裤子的数量
*/
private static int NUM_PANTS = 200;
/*
* 仓库内电子产品的数量
*/
private static int NUM_ELECTRONICS = 50;
/**
* 存储产品的集合类
*/
public List<Clothes> clothesStorage = new ArrayList<Clothes>();
public List<Pants> pantsStorage = new ArrayList<Pants>();
public List<Electronics> electronicsStorage = new ArrayList<Electronics>();;
/**
* 装产品
*/
public void install(){
for(int i=0 ; i<NUM_CLOTHES ; i++){
clothesStorage.add(new Clothes("Clothes"+(i+1), new Random().random()));
}
for(int i=0 ; i<NUM_PANTS ; i++){
pantsStorage.add(new Pants("Pants"+(i+1), new Random().random()));
}
for(int i=0 ; i<NUM_ELECTRONICS ; i++){
electronicsStorage.add(new Electronics("Electronic"+(i+1) , new Random().random()));
}
}
/* public static void main(String[] args) {
for(int i=0;i<10;i++){
System.out.println(new Random().random());
}
}*/
}
/**
* 价格随机数类
* @author TisaKong
* 2015-2-2
*/
class Random{
public double random(){
java.util.Random r = new java.util.Random();
r.setSeed(System.nanoTime());
return r.nextDouble()*100;
}
}
顾客Customer
package Strategy;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
public class Customer {
/**
* 去某个商场 买几样东西
* @param market
* @return
*/
public List<Things> goShopping(Market market , Map<String , Integer > ... products){
//获取购买商品的数量
int numClothes=0 , numPants=0 , numElectronics=0 , sum=0;
for(Map<String ,Integer > product : products){
if(product.get("clothes")!=null){
numClothes = product.get("clothes");
}else if(product.get("pants") != null){
numPants = product.get("pants");
}else if(product.get("electronics") != null){
numElectronics = product.get("electronics");
}
}
List<Things> haveBuy = new ArrayList<Things>();
for(int i=0;i<numClothes;i++){
haveBuy.add(market.buy("clothes"));
}
for(int i=0;i<numPants;i++){
haveBuy.add(market.buy("pants"));
}
for(int i=0;i<numElectronics;i++){
haveBuy.add(market.buy("electronics"));
}
return haveBuy;
}
}
商品打折信息
package Strategy;
public class Discount {
public static final double CLOTHES_DISCOUNT = 0.8;
public static final double PANTS_DISCOUNT = 0.65;
public static final double ELECTRONICS_DISCOUNT = 0.9;
}
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