层次结构分明的网站配色方案,网站建设用户需求,中国正规的加盟网站,asp.net 4.0网站开...一、策略模式
背景
针对某种业务可能存在多种实现方式#xff1b;传统方式是通过传统if…else…或者switch代码判断#xff1b;
弊端#xff1a;
代码可读性差扩展性差难以维护
策略模式简介
策略模式是一种行为型模式#xff0c;它将对象和行为分开#xff0c;将行…一、策略模式
背景
针对某种业务可能存在多种实现方式传统方式是通过传统if…else…或者switch代码判断
弊端
代码可读性差扩展性差难以维护
策略模式简介
策略模式是一种行为型模式它将对象和行为分开将行为定义为一个行为接口和具体行为的实现。
组成
抽象策略类(Strategy)策略的抽象具体策略类(ConcreteStrategy)具体的策略实现一种具体实现环境类(Context)用来操作策略的上下文环境
二、代码实现
以文件存储方式为例
抽象策略类
package com.qiangesoft.file.core;import org.springframework.web.multipart.MultipartFile;/*** 文件存储策略接口** author qiangesoft* date 2024-01-06*/
public interface FileStoreStrategy {/*** 存储方式** return*/String getType();/*** 上传文件** param file* return* throws Exception*/void uploadFile(MultipartFile file) throws Exception;
}
具体策略实现
本地存储
package com.qiangesoft.file.core.local;import com.qiangesoft.file.core.FileStoreStrategy;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;/*** 文件本地存储** author qiangesoft* date 2024-01-06*/
Component
Slf4j
public class LocalStoreStrategyImpl implements FileStoreStrategy {Overridepublic String getType() {return LOCAL;}Overridepublic void uploadFile(MultipartFile file) throws Exception {log.info(upload file by local);}
}
minio存储
package com.qiangesoft.file.core.minio;import com.qiangesoft.file.core.FileStoreStrategy;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;/*** 文件minio对象存储** author qiangesoft* date 2024-01-06*/
Component
Slf4j
public class MinioStoreStrategyImpl implements FileStoreStrategy {Overridepublic String getType() {return MINIO;}Overridepublic void uploadFile(MultipartFile file) throws Exception {log.info(upload file by minio);}
}
策略上下文环境
package com.qiangesoft.file.core;import org.springframework.stereotype.Component;import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;/*** 文件存储策略上下文** author qiangesoft* date 2024-01-06*/
Component
public class FileStoreStrategyContext {/*** 策略实现类上下文*/private final MapString, FileStoreStrategy strategyMap new ConcurrentHashMap();/*** 利用Spring的发现机制将实现了FileStoreStrategy的类都放到strategyMap里面*/public FileStoreStrategyContext(ListFileStoreStrategy fileStoreStrategyList) {for (FileStoreStrategy strategy : fileStoreStrategyList) {String type strategy.getType();if (this.strategyMap.containsKey(type)) {throw new RuntimeException(String.format(Strategy [%s] is repeat!, type));}this.strategyMap.put(type, strategy);}}/*** 获取具体的策略实现类** param storeType* return*/public FileStoreStrategy getStrategy(String storeType) {FileStoreStrategy strategy strategyMap.get(storeType);if (strategy null) {throw new RuntimeException(String.format(Strategy [%s] is not found!, storeType));}return strategy;}
}调用
package com.qiangesoft.file.demo;import com.qiangesoft.file.core.FileStoreStrategy;
import com.qiangesoft.file.core.FileStoreStrategyContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;/*** Demo** author qiangesoft* date 2024-01-08*/
RestController
RequestMapping(/demo)
public class DemoController {Autowiredprivate FileStoreStrategyContext fileStoreStrategyContext;GetMapping(/upload)public String upload(String type) throws Exception {FileStoreStrategy fileStoreStrategy fileStoreStrategyContext.getStrategy(type);fileStoreStrategy.uploadFile(null);return fileStoreStrategy.getType();}} 扩展
如果新增一种存储方式只需增加一个策略实现类实现FileStoreStrategy接口重写getType方法然后再实现具体的业务逻辑
案例代码
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