springboot中的工厂模式

说到工厂模式，先说说工厂模式是什么，有什么优点

平常我们在工作开发过程中，往往因为工期问题导致整体功能设计考虑的不够周到，导致后期迭代时发现需要原有功能流程基础上追加新功能时，需要耗费更多的成本，无法轻易推翻重构，接着便是将错就错，在if else之下再来一层elseif。通过设计模式去优化代码，达到代码的复用性，减少耦合，也就是我们常说的高内聚低耦合。

通过工厂模式可以把对象的创建和使用过程分割开来。比如说 Class A 想调用 Class B的方法，那么我们无需关心B是如何创建的，直接去工厂获取就行

那我们直接上代码举例一二：

代码结构：

工厂类：

@Component
public class ConnectionFactory implements ApplicationContextAware {public static Map<String, IConnectionService> connectionMap = new HashMap<String, IConnectionService>();@Overridepublic void setApplicationContext(ApplicationContext applicationContext) throws BeansException {//根据接口类型返回相应的所有beanMap<String, IConnectionService> map = applicationContext.getBeansOfType(IConnectionService.class);for (Map.Entry<String, IConnectionService> data : map.entrySet()) {List<String> typeList = data.getValue().getType();if (CollUtil.isNotEmpty(typeList)) {for (String type : typeList) {connectionMap.put(type, data.getValue());}}}}public static IConnectionService getConnectionService(String type) {IConnectionService connectionService = connectionMap.get(type);if (ObjectUtil.isNotNull(connectionService)) {return connectionService;} else {return null;}}}

接口：

public interface IConnectionService {Integer checkConnection(Connection connection);//获取类型List<String> getType();}

实现类一：

@Slf4j
@Service
public class JdbcConnectionServiceImpl implements IConnectionService {@Overridepublic Integer checkConnection(Connection connection) {int res = 0;return res;}@Overridepublic List<String> getType() {List<String> typeList = new ArrayList<>();typeList.add(PublicConstant.DATA_SOURCE_TYPE.MYSQL_TYPE);return typeList;}
}

调取：

@RequestMapping(value = "/checkConnection", method = RequestMethod.POST)@ResponseBodypublic String checkConnection(@RequestBody Connection connection) {if(StringUtils.isEmpty(connection.getDataSourceType())){return ReturnMapUtils.setFailedMsgRtnJsonStr("请传入数据源类型");}Integer integer = 0;//获取对应的Service对象IConnectionService service = ConnectionFactory.getConnectionService(connection.getDataSourceType());//检查连接是否成功if (ObjectUtil.isNotNull(service)) {integer = service.checkConnection(connection);}if (integer.equals(0)) {return ReturnMapUtils.setFailedMsgRtnJsonStr("连接失败");} else {return ReturnMapUtils.setSucceededMsgRtnJsonStr("连接成功");}}

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实现方式二：

//工厂类
import java.util.Map;
import com.google.common.collect.Maps;public class TypeCheckFactory {private static Map<String, TypeCheck> strategyMap = Maps.newHashMap();public static TypeCheck getInvokeStrategy(String name) {return strategyMap.get(name);}public static void register(String name, TypeCheck stopCheck) {if (StringUtils.isEmpty(name) || stopCheck == null) {return;}strategyMap.put(name, stopCheck);}public static Map<String, TypeCheck> getStrategyMap() {return strategyMap;}
}

//实现类：

@Component
public class LSHAnalysisSimilerType implements StopCheck {@Overridepublic String doInformationVerification() {return null;}@Overridepublic String doInformationVerification(CheckFactoryBean checkFactoryBean) {return null;}//这个方法很关键，自动注入的关键，将当前对象注入进去当一个类实现这个接口之后，Spring启动时，初始化Bean时，若该Bean实现InitializingBean接口，则会自动调用afterPropertiesSet()方法，完成一些用户自定义的初始化操作@Overridepublic void afterPropertiesSet() throws Exception {StopCheckFactory.register("LSHAnalysisSimilerType", this);}
}

//调取：

public static String typeMetaInformation(List<TypeVo> parentStopsVos, TypeVo toStopsVo,boolean checkFlag){String categories = getTypeCheckCategories(toStopsVo);TypeCheck typeCheck = StopCheckFactory.getInvokeStrategy(categories);        return typeCheck.doInformationVerification("123");}