使用SpringBoot实现策略模式

1-定义一个抽奖接口LotteryService

public interface LotteryService {

    /**
     * 抽奖
     */
    void lottery();
}

2-实现三种不同的抽奖策略

@Service("CharacterLotteryService")
public class CharacterLotteryServiceImpl implements LotteryService {
    @Override
    public void lottery() {
        System.out.println("角色池抽奖");
    }
}

@Service("IndefiniteLotteryService")
public class IndefiniteLotteryServiceImpl implements LotteryService {
    @Override
    public void lottery() {
        System.out.println("常驻抽奖");

    }
}

@Service("WeaponLotteryService")
public class WeaponLotteryServiceImpl implements LotteryService {
    @Override
    public void lottery() {
        System.out.println("武器池抽奖");
    }
}

@Service("xxx")里的内容是注入到Spring容器中bean的名字，等会使用策略工厂获取的时候需要用到；

3-定义一个枚举类，这样可以通过编码获取注入到Spring容器中的bean名称。

public enum LotteryEnum {

    CHARACTER_ONE("00","IndefiniteLotteryService"),
    CHARACTER_TWO("01","CharacterLotteryService"),
    INDEFINITE("02","CharacterLotteryService"),
    WEAPON("03","WeaponLotteryService");

    /**
     * 00-常驻 01-角色活动1 02-角色活动2 03-武器活动
     */
    private String code;

    /**
     * 策略
     */
    private String strategy;

    LotteryEnum(String code, String strategy) {
        this.strategy = strategy;
        this.code = code;
    }

    public static String getStrategy(String code) {
        for (LotteryEnum value : LotteryEnum.values()) {
            if (value.getCode().equals(code)){
                return value.getStrategy();
            }
        }
        throw new ServiceException("没有该类型的策略");
    }

    public String getStrategy(){
        return strategy;
    }

    public void setStrategy(String strategy) {
        this.strategy = strategy;
    }

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }

    @Override
    public String toString() {
        return "LotteryEnum{" +
                "strategy='" + strategy + '\'' +
                ", code='" + code + '\'' +
                '}';
    }
}

4-实现策略工厂类

@Service
public class LotteryStrategy {

    @Resource
    Map<String, LotteryService> map = new ConcurrentHashMap<>();

    public LotteryService getLotteryService(String code){
        String strategy = LotteryEnum.getStrategy(code);
        return map.get(strategy);
    }
}

使用@Resource注解可以获取到Spring容器中的三个具体策略的bean.用ConcurrentHashMap还可以防止线程不安全问题。

5-测试

@SpringBootTest
class LotteryStrategyTest {

    @Resource
    private LotteryStrategy lotteryStrategy;

    @Test
    void strategy(){
        LotteryService lotteryService1 = lotteryStrategy.getLotteryService("01");
        LotteryService lotteryService2 = lotteryStrategy.getLotteryService("02");
        LotteryService lotteryService3 = lotteryStrategy.getLotteryService("03");
        LotteryService lotteryService4 = lotteryStrategy.getLotteryService("00");

        lotteryService1.lottery();
        lotteryService2.lottery();
        lotteryService3.lottery();
        lotteryService4.lottery();
    }

}

结果