策略模式

业务场景：操作类型三种。0、1、2、为了层次清晰，减少if判断，所以使用。

目录结构：

1、server类

@Transactional
public void saveQuestion(QuestionRequest request) {
   IQuestionSaveHandler handler = null;

   try {
      handler = SpringContextHolder.getBean(IQuestionSaveHandler.QUESTION_SAVE_HANDLER_BEAN_PREFIX+request.getHandlerType(), IQuestionSaveHandler.class);
   }catch(Exception e) {
      throw new IntfException("未知的处理类型 "+request.getHandlerType());
   }
   handler.questionSave(request);

}

2、IQuestionSaveHandler类

public interface IQuestionSaveHandler {

   public final static String QUESTION_SAVE_HANDLER_BEAN_PREFIX = "questionSaveHandler_";
   /**
    * 问题保存
    */
   public void questionSave(QuestionRequest request);
}

3、AbstractQuestionSaveHandler类

package com.yemast.road.roadpatrol.server.service.strategy.questionsave;

import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cglib.beans.BeanCopier;
import com.yemast.road.roadpatrol.server.service.strategy.IQuestionSaveHandler;
import com.yemast.road.roadsso.common.exception.IntfException;
import com.yemast.road.roadsso.common.util.CommonUtil;

/**
 * 抽象类
 * 
 * 
 */
public abstract class AbstractQuestionSaveHandler implements IQuestionSaveHandler {
   @Autowired
   protected SectionService sectionService;
   @Autowired
   protected InformationService informationService;

   @Autowired
   protected UserQuestionService userQuestionService;
   
   @Override
   public void questionSave(QuestionRequest request) {

      // 方法体
      

   public abstract void doProcess(Question question, QuestionRequest request);
}

4、QuestionSaveHandlerImmediate 类

package com.yemast.road.roadpatrol.server.service.strategy.questionsave;

import com.yemast.road.roadpatrol.core.entity.patrol.Question;
import com.yemast.road.roadpatrol.core.entity.patrol.QuestionProcess;


@Service(IQuestionSaveHandler.QUESTION_SAVE_HANDLER_BEAN_PREFIX+"0")
public class QuestionSaveHandlerImmediate extends AbstractQuestionSaveHandler{

   @Override
   public void doProcess(Question question, QuestionRequest request) {
     //方法体

   }

}

5、QuestionSaveHandlerInstructions 类

package com.yemast.road.roadpatrol.server.service.strategy.questionsave;

import com.yemast.road.roadpatrol.core.response.PushParams;
import org.springframework.stereotype.Service;

import com.yemast.road.roadpatrol.core.entity.patrol.Question;
import com.yemast.road.roadpatrol.core.entity.patrol.QuestionProcess;



@Service(IQuestionSaveHandler.QUESTION_SAVE_HANDLER_BEAN_PREFIX+"2")
public class QuestionSaveHandlerInstructions extends AbstractQuestionSaveHandler{

   @Override
   public void doProcess(Question question, QuestionRequest request) {

      //方法体
   }
}

6、QuestionSaveHandlerNotify 类

package com.yemast.road.roadpatrol.server.service.strategy.questionsave;

import com.yemast.road.roadpatrol.core.response.PushParams;
import org.springframework.stereotype.Service;

import com.yemast.road.roadpatrol.core.entity.patrol.Question;
import com.yemast.road.roadpatrol.core.entity.patrol.QuestionProcess;
import com.yemast.road.roadpatrol.core.entity.patrol.Task;


@Service(IQuestionSaveHandler.QUESTION_SAVE_HANDLER_BEAN_PREFIX+"1")
public class QuestionSaveHandlerNotify extends AbstractQuestionSaveHandler{


  
   @Override
   public void doProcess(Question question, QuestionRequest request) {
      //方法体


   }

}

策略模式

原文：https://www.cnblogs.com/zhangcf420/p/10315975.html