package com.nf147.demo.dao;import com.nf147.demo.entity.News;
import org.springframework.data.jpa.repository.JpaRepository;public interface NewsMapper extends JpaRepository<News,Integer> {  //第一个参数是实体类，第二个是id的类型

}

package com.nf147.demo.entity;import javax.persistence.*;@Entity
@Table(name = "news") //表名
public class News {@Id@GeneratedValue(strategy = GenerationType.IDENTITY)  //标明该字段是自动增长private int id;private String title;private String body;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getTitle() {return title;}public void setTitle(String title) {this.title = title;}public String getBody() {return body;}public void setBody(String body) {this.body = body;}
}

package com.nf147.demo.service;import com.nf147.demo.entity.News;import java.util.List;public interface NewsService {List<News> listAll();void add (News news);void del (int id);void update(News news);
}

package com.nf147.demo.service;import com.nf147.demo.dao.NewsMapper;
import com.nf147.demo.entity.News;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;import java.util.List;@Service
public class NewsServiceImp implements NewsService {@Autowiredprivate NewsMapper newsMapper;@Override@Cacheable("listNews")public List<News> listAll() {return newsMapper.findAll();}@Overridepublic void add(News news) {newsMapper.save(news);}@Overridepublic void del(int id) {newsMapper.deleteById(id);}@Overridepublic void update(News news) {newsMapper.save(news);}
}

package com.nf147.demo.controller;import com.nf147.demo.entity.News;
import com.nf147.demo.service.NewsServiceImp;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;import java.util.List;@RestControllerpublic class NewsController {@Autowiredprivate NewsServiceImp newsServiceImp;//查询@RequestMapping(value = "/listNews", method = RequestMethod.GET)public List<News> getNews() {return newsServiceImp.listAll();}//添加 http://localhost:8082/listNewsAdd?title=标题&body=随便给的内容@RequestMapping(value = "/listNewsAdd", method = RequestMethod.GET)public void add(News news) {newsServiceImp.add(news);}//删除//地址栏写法 http://localhost:8082/listNewsdel?id=7@RequestMapping(value = "/listNewsdel", method = RequestMethod.GET)public void del(int id) {newsServiceImp.del(id);}//修改//地址栏写法  http://localhost:8082/listNewsupdate?id=6&title=好好&body=学习@RequestMapping(value = "/listNewsupdate", method = RequestMethod.GET)public void del(News news) {newsServiceImp.update(news);}}