IService和他的多个ServiceImpl

记录简单的接口和他的多个实现类的准确调用

• 代码实现
• 注解注入方式

Spring 中 IService 有多个实现类，它是如何知道该注入哪个 ServiceImpl 类？

先上接口代码

public interface IWorkFlowHandler {

    
    IPage listPage(REQ1 req1);

    
    void add(REQ2 req2) throws IllegalAccessException;
}

抽象类

@Slf4j
@Transactional(propagation = Propagation.REQUIRED, rollbackFor = Exception.class)
public abstract class AbstractWorkFlowTemplate
        extends WorkflowbaseMethods
        implements IWorkFlowHandler {

    @Override
    public void add(REQ2 req2) throws IllegalAccessException {
    
    // 方法的具体实现
        .....
        .....
        .....
        .....
        }
    }
}

实现类

@Service("cbmWorkflowHandler")
public class CbmWorkflowHandler extends AbstractWorkFlowTemplate<
        CbmQueryParam,
        MerCbmVO,
        CbmAddParam,
        CbmUpdateParam,
        CbmChangeStatusParam,
        CbmDeleteParam,
        CbmPassParam,
        CbmRejectParam,
        CbmToBeApprovalParam,
        MerCbmVO,
        CbmApprovalRecordParam> {
         @Override
    protected Integer listPage(CbmAddParam cbmAddParam) {
        //listPage方法的具体实现
        ..................
        list = getCurrentAllChildrenDeptIds();
        .......
        .......
        ........
        .........
       }
    }

@Service("payrollWorkflowHandler")
public class PayrollWorkflowHandler extends AbstractWorkFlowTemplate<
        PayrollQueryParam,
        MerPayrollVO,
        PayrollAddParam,
        PayrollUpdateParam,
        PayrollChangeStatusParam,
        PayrollDeleteParam,
        PayrollPassParam,
        PayrollRejectParam,
        PayrollToBeApprovalParam,
        MerPayrollVO,
        PayRollApprovalRecordParam> {
         @Override
    protected Integer listPage(CbmAddParam cbmAddParam) {
        //listPage方法的具体实现
        .......
        .......
        ........
        .........
       }
    }

@Service("posWorkflowHandler")
public class PosWorkflowHandler extends AbstractWorkFlowTemplate<
        PosQueryParam,
        MerPosVO,
        PosAddParam,
        PosUpdateParam,
        PosChangeStatusParam,
        PosDeleteParam,
        PosPassParam,
        PosRejectParam,
        PosToBeApprovalParam,
        MerPosVO,
        PosApprovalRecordParam> {
         @Override
    protected Integer listPage(CbmAddParam cbmAddParam) {
        //listPage方法的具体实现
        .......
        .......
        ........
        .........
       }
    }

@Service("wechatWorkflowHandler")
public class WechatWorkflowHandler extends AbstractWorkFlowTemplate<
        WechatQueryParam,
        MerchantInformationChannelVO,
        WechatAddParam,
        WechatUpdateParam,
        WechatChangeStatusParam,
        WechatDeleteParam,
        WechatPassParam,
        WechatRejectParam,
        WechatToBeApprovalParam,
        MerchantInformationChannelVO,
        WechatApprovalRecordParam
        >  {
         @Override
    protected Integer listPage(CbmAddParam cbmAddParam) {
        //listPage方法的具体实现
        .......
        .......
        ........
        .........
       }
    }

用来调用的类
这里说明下，spring的特性，建立map后，spring会自动将@service中的内容导入进map的key里面

@Component
public class WorkflowHelper {

    @Autowired
    private Map map;

    public IWorkFlowHandler getHandler(WorkflowEnums.Type type) {
        return map.get(type.getBeanName());
    }
}

用到的枚举

public class WorkflowEnums {
public enum Type {
        PAYROLL("payroll", "payrollWorkflowHandler", "代发薪"),
        POS("pos", "posWorkflowHandler", "pos"),
        WECHAT("wechat", "wechatWorkflowHandler", "微信"),
        CBM("cbm", "cbmWorkflowHandler", "cbm");
        public String alias;
        private String beanName;
        private String value;

        Type(String alias, String beanName, String value) {
            this.alias = alias;
            this.beanName = beanName;
            this.value = value;
        }

        public String getAlias() {
            return alias;
        }

        public void setAlias(String alias) {
            this.alias = alias;
        }

        public String getBeanName() {
            return beanName;
        }

        public void setBeanName(String beanName) {
            this.beanName = beanName;
        }

        public String getValue() {
            return value;
        }

        public void setValue(String value) {
            this.value = value;
        }
    }
}

方法的调用

public Result> listPage(@Valid @RequestBody CbmQueryParam queryParam) {
            IPage returnPage = workflowHelper.getHandler(WorkflowEnums.Type.CBM).listPage(queryParam);
            return Result.success(returnPage);
        }

此抽象类还继承了一个工具集
在同包的CbmWorkflowHandler类中直接调用了该方法

@Component
public class WorkflowbaseMethods {
    protected List getCurrentAllChildrenDeptIds() {
     // 方法的具体实现
     .................
     .............
     ....................
     }
}

方法其一
Controller中注入service的时候使用@Resource(type = 类名.class)来指定注入哪一个

方法其二
1、每个service的impl都可以指定名称（使用@Service（“名称”））

2、Controller中注入service的时候使用名称来指定注入哪一个（使用@Resource(name=“名称”)）。

接口

public interface HumanService {
    public String name();
}

实现接口类

@Service("teacherService")
public class TeacherServiceImpl implements HumanService {
    @Override
    public String name() {
        System.out.println("teacher");
        return "teacher";
    }
}
@Service("doctorService")
public class DoctorServiceImpl implements HumanService {
    @Override
    public String name() {
        System.out.println("doctor");
        return "doctor";
    }
}

控制器

@RestController
public class HumanController {
 
    @Resource(name="doctorService")
    private HumanService humanService;
 
    @RequestMapping("/name")
    public String name(){
        return humanService.name();
    }
}

其余方法：链接: Spring 中 IService 有多个实现类，它是如何知道该注入哪个 ServiceImpl 类？.