Springboot中Service+ServiceImpl的結構解析

爲解決移植性問題而設計的

一開始大多數項目都是直接在業務處理層的Service類中嵌入JDBC代碼，這就使得這個Service類與數據庫緊藕合，在換一種數據庫後，就要修改Service類中的sql。於是就有了controller+service+serviceImpl；  Service類設計成一個接口，使控制層只依賴這個接口；這樣，當某天這個應用要跑在其它數據庫上時，就而只需要增加一個serviceImpl類。

項目結構如下：

具體代碼如下：

PersonService

package com.service.serviceimpldemo.Service;

/**
 * description:
 * author: 
 */
public interface PersonService {
    public String name();
}

WomanServiceImpl

package com.service.serviceimpldemo.Service.impl;

import com.service.serviceimpldemo.Service.PersonService;
import org.springframework.stereotype.Service;

/**
 * description:
 * author:
 */
@Service("womanService")
public class WomanServiceImpl implements PersonService {
    @Override
    public String name(){
        return "Woman";
    }
}

ManServiceImpl

package com.service.serviceimpldemo.Service.impl;

import com.service.serviceimpldemo.Service.PersonService;
import org.springframework.stereotype.Service;

/**
 * description:
 * author: 
 */
@Service("manService")
public class ManServiceImpl implements PersonService {
    @Override
    public String name(){
     return "Man";
    }
}

PersonController

package com.service.serviceimpldemo.Controller;

import com.service.serviceimpldemo.Service.PersonService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * description:
 * author: 
 */
@RestController
public class PersonController {
    @Autowired
    
    //如果該Service有多個實現類，設置注入哪個ServiceImpl類
    @Qualifier("womanService")
    private PersonService personService;

    @RequestMapping("/name.do")
    public String name(){
        return personService.name();
    }
}