1.创建自动配置类

public class DesignPatternAutoConfiguration {
    @Autowired
    private ApplicationContext context;
   /**
    * 策略模式选择器
    */
   @Bean
   public AbstractStrategyChoose abstractStrategyChoose() {
      return new AbstractStrategyChoose(context);
    }
}    

2.spring.facotries添加自动配置类

3.创建策略选择器

 /**
  * 策略模式选择器
  */
@Configuration
public class AbstractStrategyChoose implements InitializingBean {

    private ApplicationContext context;

    /**
     * 执行策略集合
     */
    private final Map<String, AbstractExecuteStrategy> abstractExecuteStrategyMap = new HashMap<>();

    public AbstractStrategyChoose(ApplicationContext context) {
        this.context = context;
    }

    /**
     * 根据 mark 查询具体策略
     *
     * @param mark 策略标识
     * @return 实际执行策略
     */
    public AbstractExecuteStrategy choose(String mark) {
        return Optional.ofNullable(abstractExecuteStrategyMap.get(mark)).orElseThrow(() ->
 new ServiceException(String.format("[%s] 策略未定义", mark)));
    }

    /**
     * 根据 mark 查询具体策略并执行
     *
     * @param mark         策略标识
     * @param requestParam 执行策略入参
     * @param <REQUEST>    执行策略入参范型
     */
    public <REQUEST> void chooseAndExecute(String mark, REQUEST requestParam) {
        AbstractExecuteStrategy executeStrategy = choose(mark);
        executeStrategy.execute(requestParam);
    }

    /**
     * 根据 mark 查询具体策略并执行，带返回结果
     *
     * @param mark         策略标识
     * @param requestParam 执行策略入参
     * @param <REQUEST>    执行策略入参范型
     * @param <RESPONSE>   执行策略出参范型
     * @return
     */
    public <REQUEST, RESPONSE> RESPONSE chooseAndExecuteResp(String mark, REQUEST requestParam) {
        AbstractExecuteStrategy executeStrategy = choose(mark);
        return (RESPONSE) executeStrategy.executeResp(requestParam);
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        Map<String, AbstractExecuteStrategy> actual = context.getBeansOfType(AbstractExecuteStrategy.class);
        actual.forEach((beanName, bean) -> {
            AbstractExecuteStrategy beanExist = abstractExecuteStrategyMap.get(bean.mark());
            if (beanExist != null) {
                throw new ServiceException(String.format("[%s] Duplicate execution policy", bean.mark()));
            }
            abstractExecuteStrategyMap.put(bean.mark(), bean);
        });
    }
}

4.创建策略执行抽象接口

public interface AbstractExecuteStrategy<REQUEST, RESPONSE> {

    /**
     * 执行策略标识
     */
    String mark();

    /**
     * 执行策略
     *
     * @param requestParam 执行策略入参
     */
    default void execute(REQUEST requestParam) {

    }

    /**
     * 执行策略，带返回值
     *
     * @param requestParam 执行策略入参
     * @return 执行策略后返回值
     */
    default RESPONSE executeResp(REQUEST requestParam) {
        return null;
    }
}

5.使用

创建策略处理Handler实现策略抽象执行接口即可对其添加相应标记，执行方法重写 注入策略选择器即可使用