工厂+策略最佳实践

1.目录结构

2.SubjectType.java 策略枚举类

package com.sunxiansheng.design_pattern.factory_strategy.strategyenum;import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collectors;
import java.util.stream.Stream;/*** Description: 题目类型，分为单选、多选、判断、简答** @Author sun* @Create 2024/9/8 21:11* @Version 1.0*/
public enum SubjectType {// 单选题SINGLE_CHOICE(1, "单选题"),// 多选题MULTIPLE_CHOICE(2, "多选题"),// 判断题JUDGMENT(3, "判断题"),// 简答题SHORT_ANSWER(4, "简答题");private int code;private String desc;SubjectType(int code, String desc) {this.code = code;this.desc = desc;}// get方法public int getCode() {return code;}public String getDesc() {return desc;}// 将枚举转为mappublic static Map<Integer, SubjectType> enumeratedMaps = Stream.of(SubjectType.values()).collect(Collectors.toMap(SubjectType::getCode, Function.identity()));/*** 根据code获取题目类型** @param code* @return*/public static SubjectType getSubjectType(int code) {return enumeratedMaps.get(code);}}

3.ISubjectStrategy.java 策略接口

package com.sunxiansheng.design_pattern.factory_strategy.strategy;import com.sunxiansheng.design_pattern.factory_strategy.strategyenum.SubjectType;/*** Description: 题目策略** @Author sun* @Create 2025/2/11 12:06* @Version 1.0*/
public interface ISubjectStrategy {/*** 获取题目类型** @return*/SubjectType getSubjectType();/*** 处理题目*/void handleQuestion();
}

4.策略接口实现类

1.Judgment.java

package com.sunxiansheng.design_pattern.factory_strategy.strategy;import com.sunxiansheng.design_pattern.factory_strategy.strategyenum.SubjectType;/*** Description: 判断题策略** @Author sun* @Create 2024/9/8 21:22* @Version 1.0*/
public class Judgment implements ISubjectStrategy {@Overridepublic void handleQuestion() {System.out.println("处理判断题");}@Overridepublic SubjectType getSubjectType() {return SubjectType.JUDGMENT;}
}

2.MultipleChoice.java

package com.sunxiansheng.design_pattern.factory_strategy.strategy;import com.sunxiansheng.design_pattern.factory_strategy.strategyenum.SubjectType;/*** Description: 多选题策略** @Author sun* @Create 2024/9/8 21:21* @Version 1.0*/
public class MultipleChoice implements ISubjectStrategy {@Overridepublic void handleQuestion() {System.out.println("处理多选题");}@Overridepublic SubjectType getSubjectType() {return SubjectType.MULTIPLE_CHOICE;}
}

3.ShortAnswer.java

package com.sunxiansheng.design_pattern.factory_strategy.strategy;import com.sunxiansheng.design_pattern.factory_strategy.strategyenum.SubjectType;/*** Description: 简答题策略** @Author sun* @Create 2024/9/8 21:22* @Version 1.0*/
public class ShortAnswer implements ISubjectStrategy {@Overridepublic void handleQuestion() {System.out.println("处理简答题");}@Overridepublic SubjectType getSubjectType() {return SubjectType.SHORT_ANSWER;}
}

4.SingleChoice.java

package com.sunxiansheng.design_pattern.factory_strategy.strategy;import com.sunxiansheng.design_pattern.factory_strategy.strategyenum.SubjectType;/*** Description: 单选题策略** @Author sun* @Create 2024/9/8 21:20* @Version 1.0*/
public class SingleChoice implements ISubjectStrategy {@Overridepublic void handleQuestion() {System.out.println("处理单选题");}@Overridepublic SubjectType getSubjectType() {return SubjectType.SINGLE_CHOICE;}
}

5.Strategy.java 策略工厂

package com.sunxiansheng.design_pattern.factory_strategy.factory;import com.sunxiansheng.design_pattern.factory_strategy.strategy.ISubjectStrategy;
import com.sunxiansheng.design_pattern.factory_strategy.strategyenum.SubjectType;import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;/*** Description: 策略工厂** @Author sun* @Create 2024/9/8 21:23* @Version 1.0*/
public class Strategy {/*** 正常情况下是使用Spring的依赖注入，这里直接使用反射模拟了*/private List<ISubjectStrategy> strategies = new ArrayList<>();/*** 策略map，将list转为map，方便根据题目类型获取策略*/private Map<SubjectType, ISubjectStrategy> strategyMap = new HashMap<>();{// 反射模拟Spring的依赖注入try {Class<?> singleChoice = Class.forName("com.sunxiansheng.design_pattern.factory_strategy.strategy.SingleChoice");Class<?> multipleChoice = Class.forName("com.sunxiansheng.design_pattern.factory_strategy.strategy.MultipleChoice");Class<?> judgment = Class.forName("com.sunxiansheng.design_pattern.factory_strategy.strategy.Judgment");Class<?> shortAnswer = Class.forName("com.sunxiansheng.design_pattern.factory_strategy.strategy.ShortAnswer");strategies.add((ISubjectStrategy) singleChoice.newInstance());strategies.add((ISubjectStrategy) multipleChoice.newInstance());strategies.add((ISubjectStrategy) judgment.newInstance());strategies.add((ISubjectStrategy) shortAnswer.newInstance());} catch (Exception e) {throw new RuntimeException(e);}}{// 将list转为mapstrategies.forEach(strategy -> strategyMap.put(strategy.getSubjectType(), strategy));}/*** 根据题目类型获取策略** @param subjectType* @return*/public ISubjectStrategy getStrategy(SubjectType subjectType) {return strategyMap.get(subjectType);}}

6.Client.java 客户端

package com.sunxiansheng.design_pattern.factory_strategy;import com.sunxiansheng.design_pattern.factory_strategy.factory.Strategy;
import com.sunxiansheng.design_pattern.factory_strategy.strategyenum.SubjectType;/*** Description: 客户端** @Author sun* @Create 2024/9/8 21:34* @Version 1.0*/
public class Client {public static void main(String[] args) {// 策略工厂Strategy strategy = new Strategy();// 四种策略strategy.getStrategy(SubjectType.SINGLE_CHOICE).handleQuestion();strategy.getStrategy(SubjectType.MULTIPLE_CHOICE).handleQuestion();strategy.getStrategy(SubjectType.JUDGMENT).handleQuestion();strategy.getStrategy(SubjectType.SHORT_ANSWER).handleQuestion();}
}

7.小结

工厂+策略首先要有一个策略的枚举类，设置四种题目类型的枚举，然后一个策略接口，有两个方法，一个方法返回当前策略的枚举类型，另一个方法就是对目前题目类型的处理逻辑，去实现接口即可。接下来就要实现一个策略工厂，使用Spring的属性注入，将四种策略注入进来，然后在Bean的初始化阶段，将四种策略的List转换为Map，最后提供一个get方法，可以根据题目类型的枚举去获取不同的策略。