7天學會設計模式 CHAP06 策略模式 Strategy

7天學會設計模式
http://www.books.com.tw/products/0010750585

chap06.
策略模式 Strategy
目的：將各種可以互換的演算法（策略）包裝成一個類別。

package com.ssc24.chap06.demo01;
public class Adventurer {
 FightStrategy fightStrategy;
 public Adventurer() {
  System.out.println("冒險者");
 }
 public void attack() {
  if (fightStrategy == null) {
   fightStrategy = new NormalAttack();
  }
  fightStrategy.execute();
 }
 public void choiceStrategy(FightStrategy fightStrategy) {
  this.fightStrategy = fightStrategy;
 }
}

package com.ssc24.chap06.demo01;
public interface FightStrategy {
 void execute();
}

package com.ssc24.chap06.demo01;
public class NormalAttack implements FightStrategy {
 @Override
 public void execute() {
  System.out.println("使用一般攻擊");
 }
}

package com.ssc24.chap06.demo01;
public class UseItem implements FightStrategy {
 @Override
 public void execute() {
  System.out.println("使用道具，丟火把");

 }
}

package com.ssc24.chap06.demo01;
public class UseSkill implements FightStrategy {
 @Override
 public void execute() {
  System.out.println("使用超級痛的攻擊技能");

 }
}

package com.ssc24.chap06.demo01;
import static org.junit.Assert.*;
import org.junit.Test;
public class FightStrategyTest {
 @Test
 public void test() {
  System.out.println("===策略模式測試===");
  Adventurer adventurer = new Adventurer();
  System.out.println("出現史萊姆");
  adventurer.attack();
  System.out.println("出現非常巨大的史萊姆");
  adventurer.choiceStrategy(new UseSkill());
  adventurer.attack();
  System.out.println("出現不怕刀槍的殭屍");
  adventurer.choiceStrategy(new UseItem());
  adventurer.attack();
 }
}

/**
===策略模式測試===
冒險者
出現史萊姆
使用一般攻擊
出現非常巨大的史萊姆
使用超級痛的攻擊技能
出現不怕刀槍的殭屍
使用道具，丟火把
**/

package com.ssc24.chap06.demo02;
import java.util.Comparator;
public class SortVillageByArea implements Comparator<Village> {
 @Override
 public int compare(Village o1, Village o2) {
  if (o1.area > o2.area){
   return 1;
  }
  if (o1.area < o2.area){
   return -1;
  }
  return 0;
 }
}

package com.ssc24.chap06.demo02;
import java.util.Comparator;
public class SortVillageById implements Comparator<Village> {
 @Override
 public int compare(Village o1, Village o2) {
  if (o1.id > o2.id){
   return 1;
  }
  if (o1.id < o2.id){
   return -1;
  }
  return 0;
 }
}

package com.ssc24.chap06.demo02;
import java.util.Comparator;
public class SortVillageByName implements Comparator<Village> {
 @Override
 public int compare(Village o1, Village o2) {
  if (o1.name.charAt(0) > o2.name.charAt(0)){
   return 1;
  }
  if (o1.name.charAt(0) < o2.name.charAt(0)){
   return -1;
  }
  return 0;
 }
}

package com.ssc24.chap06.demo02;
import java.util.Comparator;
public class SortVillageByPopulation implements Comparator<Village> {
 @Override
 public int compare(Village o1, Village o2) {
  if (o1.population > o2.population){
   return 1;
  }
  if (o1.population < o2.population){
   return -1;
  }
  return 0;
 }
}

package com.ssc24.chap06.demo02;
public class Village {
 public int id;
 public String name;
 public int population;
 public double area;
 public Village ( int id,String name,int population,double area){
  this.id = id;
  this.name = name;
  this.population = population;
  this.area = area;
 }
 public String toString(){
  return id + "." + name + "(人口：" + population + " 面積: " + area + ")"; 
 }
}

package com.ssc24.chap06.demo02;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class StrategyExample {
 public static void main(String[] args) {
  System.out.println("===裝飾者模式 測試===");
  Village appleFarm = new Village(3, "apple farm", 32, 5.1);
  Village barnField = new Village(1, "barn field", 22, 1.7);
  Village capeValley = new Village(2, "cape valley", 10, 10.2);
  List<Village> villages = new ArrayList<Village>();
  villages.add(appleFarm);
  villages.add(barnField);
  villages.add(capeValley);
  System.out.println("沒排序過");
  showList(villages);
  System.out.println("根據ID排序");
  Collections.sort(villages,new SortVillageById());
  showList(villages);
  System.out.println("根據名字排序");
  Collections.sort(villages,new SortVillageByName());
  showList(villages);
  System.out.println("根據人口排序");
  Collections.sort(villages,new SortVillageByPopulation());
  showList(villages);
  System.out.println("根據面積排序");
  Collections.sort(villages,new SortVillageByArea());
  showList(villages);
 }
 public static void showList(List<Village> list) {
  for (Village v : list) {
   System.out.println(v);
  }
 }
}

/**
===裝飾者模式 測試===
沒排序過
3.apple farm(人口：32 面積: 5.1)
1.barn field(人口：22 面積: 1.7)
2.cape valley(人口：10 面積: 10.2)
根據ID排序
1.barn field(人口：22 面積: 1.7)
2.cape valley(人口：10 面積: 10.2)
3.apple farm(人口：32 面積: 5.1)
根據名字排序
3.apple farm(人口：32 面積: 5.1)
1.barn field(人口：22 面積: 1.7)
2.cape valley(人口：10 面積: 10.2)
根據人口排序
2.cape valley(人口：10 面積: 10.2)
1.barn field(人口：22 面積: 1.7)
3.apple farm(人口：32 面積: 5.1)
根據面積排序
1.barn field(人口：22 面積: 1.7)
3.apple farm(人口：32 面積: 5.1)
2.cape valley(人口：10 面積: 10.2)
**/